From b5475eb38b8b79a13a0a9e8a6cb68755b84f0c7b Mon Sep 17 00:00:00 2001 From: Vas Crabb Date: Tue, 7 Mar 2023 01:39:42 +1100 Subject: Various updates, mostly around Lua: Compile Lua as C++. When Lua is compiled as C, it uses setjmp/longjmp for error handling, resulting in failure to unwind intermediate stack frames. Trying to ensure no objects with non-trivial destructors are in scope when raising a Lua error is error-prone. In particular, converting an exception to a Lua error becomes convoluted, and raising a Lua error from a constructor is effectively impossible. Updated Lua to 5.4.4 - this includes a brand-new garbage collector implementation with better performance. The main thing removed is the deprecated bitlib. Updated sol2 to version 3.3.0 - this adds support for Lua 5.4 and fixes a number of issues, including not correctly handling errors when Lua is built as C++. Updated LuaFileSystem to version 1.8.0 - this adds support for symbolic links on Windows, as well as Lua 5.4 compatibility. Updated LuaSQLite3 to version 0.9.5 - this fixes issues in multi-threaded environments, as well as Lua 5.4 compatibility. Fixed double-free after attempting to construct a debugger expression from Lua with an invalid string, and exposed expression error to Lua in a better way. Added warning level print function to Lua. Fixed saving cheats with shift operators in expressions, although this code isn't actually used as there's no cheat editor. --- 3rdparty/lsqlite3/HISTORY | 15 +- 3rdparty/lsqlite3/README | 12 +- 3rdparty/lsqlite3/doc/lsqlite3.wiki | 64 +- 3rdparty/lsqlite3/lsqlite3-0.9.4-0.rockspec | 43 - 3rdparty/lsqlite3/lsqlite3-0.9.5-1.rockspec | 39 + 3rdparty/lsqlite3/lsqlite3.c | 76 +- .../lsqlite3/lsqlite3complete-0.9.5-1.rockspec | 40 + 3rdparty/lsqlite3/test/test.lua | 2 +- 3rdparty/lsqlite3/test/tests-sqlite3.lua | 40 + 3rdparty/lua/Makefile | 28 +- 3rdparty/lua/README | 2 +- 3rdparty/lua/doc/contents.html | 109 +- 3rdparty/lua/doc/lua.1 | 93 +- 3rdparty/lua/doc/lua.css | 33 +- 3rdparty/lua/doc/manual.html | 3452 +++++--- 3rdparty/lua/doc/readme.html | 117 +- 3rdparty/lua/src/Makefile | 87 +- 3rdparty/lua/src/lapi.c | 762 +- 3rdparty/lua/src/lapi.h | 29 +- 3rdparty/lua/src/lauxlib.c | 431 +- 3rdparty/lua/src/lauxlib.h | 81 +- 3rdparty/lua/src/lbaselib.c | 175 +- 3rdparty/lua/src/lbitlib.c | 233 - 3rdparty/lua/src/lcode.c | 1175 ++- 3rdparty/lua/src/lcode.h | 34 +- 3rdparty/lua/src/lcorolib.c | 100 +- 3rdparty/lua/src/lctype.c | 43 +- 3rdparty/lua/src/lctype.h | 18 +- 3rdparty/lua/src/ldblib.c | 105 +- 3rdparty/lua/src/ldebug.c | 580 +- 3rdparty/lua/src/ldebug.h | 32 +- 3rdparty/lua/src/ldo.c | 823 +- 3rdparty/lua/src/ldo.h | 41 +- 3rdparty/lua/src/ldump.c | 197 +- 3rdparty/lua/src/lfunc.c | 217 +- 3rdparty/lua/src/lfunc.h | 45 +- 3rdparty/lua/src/lgc.c | 1419 +++- 3rdparty/lua/src/lgc.h | 138 +- 3rdparty/lua/src/linit.c | 7 +- 3rdparty/lua/src/liolib.c | 151 +- 3rdparty/lua/src/ljumptab.h | 112 + 3rdparty/lua/src/llex.c | 116 +- 3rdparty/lua/src/llex.h | 12 +- 3rdparty/lua/src/llimits.h | 122 +- 3rdparty/lua/src/lmathlib.c | 438 +- 3rdparty/lua/src/lmem.c | 177 +- 3rdparty/lua/src/lmem.h | 72 +- 3rdparty/lua/src/loadlib.c | 278 +- 3rdparty/lua/src/lobject.c | 353 +- 3rdparty/lua/src/lobject.h | 747 +- 3rdparty/lua/src/lopcodes.c | 190 +- 3rdparty/lua/src/lopcodes.h | 416 +- 3rdparty/lua/src/lopnames.h | 103 + 3rdparty/lua/src/loslib.c | 95 +- 3rdparty/lua/src/lparser.c | 978 ++- 3rdparty/lua/src/lparser.h | 80 +- 3rdparty/lua/src/lprefix.h | 4 +- 3rdparty/lua/src/lstate.c | 245 +- 3rdparty/lua/src/lstate.h | 259 +- 3rdparty/lua/src/lstring.c | 135 +- 3rdparty/lua/src/lstring.h | 22 +- 3rdparty/lua/src/lstrlib.c | 718 +- 3rdparty/lua/src/ltable.c | 769 +- 3rdparty/lua/src/ltable.h | 32 +- 3rdparty/lua/src/ltablib.c | 68 +- 3rdparty/lua/src/ltm.c | 174 +- 3rdparty/lua/src/ltm.h | 37 +- 3rdparty/lua/src/lua.c | 486 +- 3rdparty/lua/src/lua.h | 64 +- 3rdparty/lua/src/luac.c | 472 +- 3rdparty/lua/src/luaconf.h | 323 +- 3rdparty/lua/src/lualib.h | 11 +- 3rdparty/lua/src/lundump.c | 276 +- 3rdparty/lua/src/lundump.h | 8 +- 3rdparty/lua/src/lutf8lib.c | 130 +- 3rdparty/lua/src/lvm.c | 1780 ++-- 3rdparty/lua/src/lvm.h | 93 +- 3rdparty/lua/src/lzio.c | 2 +- 3rdparty/lua/src/lzio.h | 2 +- 3rdparty/luafilesystem/.gitignore | 2 + 3rdparty/luafilesystem/.travis.yml | 37 +- 3rdparty/luafilesystem/.travis/platform.sh | 15 - 3rdparty/luafilesystem/.travis/setup_lua.sh | 101 - 3rdparty/luafilesystem/Makefile | 6 +- 3rdparty/luafilesystem/README | 23 - 3rdparty/luafilesystem/README.md | 28 + 3rdparty/luafilesystem/appveyor.yml | 41 + 3rdparty/luafilesystem/config | 12 +- 3rdparty/luafilesystem/config.win | 10 +- 3rdparty/luafilesystem/doc/us/doc.css | 233 +- 3rdparty/luafilesystem/doc/us/examples.html | 4 +- 3rdparty/luafilesystem/doc/us/index.html | 55 +- 3rdparty/luafilesystem/doc/us/license.html | 10 +- 3rdparty/luafilesystem/doc/us/manual.html | 38 +- .../luafilesystem/luafilesystem-scm-1.rockspec | 28 + .../rockspecs/luafilesystem-1.3.0-1.rockspec | 27 - .../rockspecs/luafilesystem-1.4.0-1.rockspec | 27 - .../rockspecs/luafilesystem-1.4.0-2.rockspec | 43 - .../rockspecs/luafilesystem-1.4.1-1.rockspec | 43 - .../rockspecs/luafilesystem-1.4.1rc1-1.rockspec | 43 - .../rockspecs/luafilesystem-1.4.2-1.rockspec | 26 - .../rockspecs/luafilesystem-1.5.0-1.rockspec | 27 - .../rockspecs/luafilesystem-1.6.0-1.rockspec | 27 - .../rockspecs/luafilesystem-1.6.1-1.rockspec | 27 - .../rockspecs/luafilesystem-1.6.2-1.rockspec | 27 - .../rockspecs/luafilesystem-1.6.3-1.rockspec | 28 - .../rockspecs/luafilesystem-cvs-1.rockspec | 44 - .../rockspecs/luafilesystem-cvs-2.rockspec | 26 - .../rockspecs/luafilesystem-cvs-3.rockspec | 27 - 3rdparty/luafilesystem/src/lfs.c | 1324 +-- 3rdparty/luafilesystem/src/lfs.def | 2 +- 3rdparty/luafilesystem/src/lfs.h | 11 +- 3rdparty/luafilesystem/tests/test.lua | 57 +- 3rdparty/sol2/sol/config.hpp | 4 +- 3rdparty/sol2/sol/forward.hpp | 733 +- 3rdparty/sol2/sol/sol.hpp | 8973 ++++++++++++-------- docs/source/techspecs/luareference.rst | 35 +- scripts/src/3rdparty.lua | 32 +- src/emu/debug/express.h | 16 +- src/frontend/mame/cheat.cpp | 10 +- src/frontend/mame/luaengine.cpp | 23 +- src/frontend/mame/luaengine.h | 1 + src/frontend/mame/luaengine.ipp | 4 +- src/frontend/mame/luaengine_debug.cpp | 60 +- 124 files changed, 21692 insertions(+), 12165 deletions(-) delete mode 100644 3rdparty/lsqlite3/lsqlite3-0.9.4-0.rockspec create mode 100644 3rdparty/lsqlite3/lsqlite3-0.9.5-1.rockspec create mode 100644 3rdparty/lsqlite3/lsqlite3complete-0.9.5-1.rockspec delete mode 100644 3rdparty/lua/src/lbitlib.c create mode 100644 3rdparty/lua/src/ljumptab.h create mode 100644 3rdparty/lua/src/lopnames.h create mode 100644 3rdparty/luafilesystem/.gitignore delete mode 100644 3rdparty/luafilesystem/.travis/platform.sh delete mode 100644 3rdparty/luafilesystem/.travis/setup_lua.sh delete mode 100644 3rdparty/luafilesystem/README create mode 100644 3rdparty/luafilesystem/README.md create mode 100644 3rdparty/luafilesystem/appveyor.yml create mode 100644 3rdparty/luafilesystem/luafilesystem-scm-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.3.0-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.4.0-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.4.0-2.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.4.1-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.4.1rc1-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.4.2-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.5.0-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.6.0-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.6.1-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.6.2-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-1.6.3-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-cvs-1.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-cvs-2.rockspec delete mode 100644 3rdparty/luafilesystem/rockspecs/luafilesystem-cvs-3.rockspec diff --git a/3rdparty/lsqlite3/HISTORY b/3rdparty/lsqlite3/HISTORY index 0fa8e7bdc92..bd9103955dc 100644 --- a/3rdparty/lsqlite3/HISTORY +++ b/3rdparty/lsqlite3/HISTORY @@ -1,9 +1,22 @@ -2016-November-?? +2018-June-30 + +Version "0.9.5" + +Since the "0.9.4-devel" release of this Lua library... + +Lua 5.4 compatibility (backward compatible with Lua 5.3, 5.2, and Lua 5.1.5). + +2016-November-13 Version "0.9.4" Since the "0.9.3-devel" release of this Lua library... +Add functions db:get_ptr() and sqlite3.open_ptr(db_ptr) to pass a db connection between threads. +Add function db:db_filename(name). +Update sqlite3_open to sqlite3_open_v2 and add open flags constants. +Thanks to Wolfgang Oertl! + Added second module 'lsqlite3complete' that statically links sqlite.c. Continue to use 'lsqlite3' for dynamic linking to 'sqlite3.so' or 'sqlite3.dll'. diff --git a/3rdparty/lsqlite3/README b/3rdparty/lsqlite3/README index 92c27b2770b..a7751bce130 100644 --- a/3rdparty/lsqlite3/README +++ b/3rdparty/lsqlite3/README @@ -1,8 +1,16 @@ -LuaSQLite 3 provides a means to manipulate SQLite3 +LuaSQLite3 provides a means to manipulate SQLite3 databases directly from lua using Lua 5. -To use this library you need SQLite3 library. +There are two modules, identical except that one links +SQLite3 dynamically, the other statically. + +The module lsqlite3 links SQLite3 dynamically. +To use this module you need the SQLite3 library. You can get it from http://www.sqlite.org/ +The module lsqlite3complete links SQLite3 statically. +The SQLite3 amalgamation source code is included in +the LuaSQLite3 distribution. + Lua 5 is available from http://www.lua.org/ diff --git a/3rdparty/lsqlite3/doc/lsqlite3.wiki b/3rdparty/lsqlite3/doc/lsqlite3.wiki index 083959f152f..baa2bed76e1 100644 --- a/3rdparty/lsqlite3/doc/lsqlite3.wiki +++ b/3rdparty/lsqlite3/doc/lsqlite3.wiki @@ -18,6 +18,7 @@
  • sqlite3.lversion
  • sqlite3.open
  • sqlite3.open_memory
  • +
  • sqlite3.open_ptr
  • sqlite3.backup_init
  • sqlite3.temp_directory
  • sqlite3.version
  • @@ -31,6 +32,7 @@
  • db:changes
  • db:close
  • db:close_vm
  • +
  • db:get_ptr
  • db:commit_hook
  • db:create_aggregate
  • db:create_collation
  • @@ -38,7 +40,8 @@
  • db:errcode
  • db:errmsg
  • db:exec
  • -
  • db:interrupt
  • +
  • db:interrupt
  • +
  • db:db_filename
  • db:isopen
  • db:last_insert_rowid
  • db:load_extension
  • @@ -129,8 +132,18 @@

    OVERVIEW

    LuaSQLite 3 is a thin wrapper around the public domain SQLite3 database engine.

    -

    The lsqlite3 module supports the creation and manipulation of -SQLite3 databases. After a sqlite3 = require('lsqlite3') the exported +

    There are two modules, identical except that one links SQLite3 dynamically, the other +statically.

    +

    The module lsqlite3 links SQLite3 dynamically. +To use this module you need the SQLite3 library (DLL or .so). +You can get it from http://www.sqlite.org/ +

    +

    The module lsqlite3complete links SQLite3 statically. +The SQLite3 amalgamation source code is included in +the LuaSQLite 3 distribution.

    +

    Both modules support the creation and manipulation of +SQLite3 databases. After a sqlite3 = require('lsqlite3') +(or sqlite3 = require('lsqlite3complete')) the exported functions are called with prefix sqlite3. However, most sqlite3 functions are called via an object-oriented interface to either database or SQL statement objects; see below for details.

    @@ -138,7 +151,9 @@ database or SQL statement objects; see below for details.

    works, it just describes the Lua binding and the available functions. For more information about the SQL features supported by SQLite3 and details about the syntax of SQL statements and queries, please see the -SQLite3 documentation http://www.sqlite.org/. Using some of the +SQLite3 documentation +http://www.sqlite.org/. +Using some of the advanced features (how to use callbacks, for instance) will require some familiarity with the SQLite3 API.

    @@ -147,15 +162,18 @@ some familiarity with the SQLite3 API.

    DOWNLOAD

    LuaSQLite 3 source code can be downloaded from its Fossil (http://lua.sqlite.org/) page.

    -

    You will also need to build or obtain an SQLite3 loadable library -(DLL or .so). See http://www.sqlite.org/ for obtaining SQLite3 +

    For lsqlite3 (but not for lsqlite3complete) you will also need to +build or obtain an SQLite3 loadable library (DLL or .so). +See http://www.sqlite.org/ for obtaining SQLite3 source code or downloading a binary SQLite3 library.


    INSTALLATION

    Luarocks (http://luarocks.org/) is the preferred mechanism -to build and install lsqlite3; it assumes an SQLite3 library is already installed.

    +to build and install lsqlite3 or lsqlite3complete; for +lsqlite3 it assumes an SQLite3 library is already installed. For +lsqlite3complete no SQLite3 library is needed.


    @@ -171,7 +189,7 @@ an enhanced version of Michael Roth's lunit called lunitxlua-sqlite3 module, and more unit tests added by Doug Currie. Get lunitx using Luarocks.

    The distribution also contains some functional tests by Tiago.

    -

    This version of lsqlite3 was tested with SQLite 3.11.0 and 3.15.0.

    +

    This version of lsqlite3 was tested with SQLite 3.11.0 and 3.15.1.


    @@ -225,7 +243,14 @@ and an error message. (In-memory databases are volatile as they are never stored on disk.)

    - +

    sqlite3.open_ptr

    +
    +        sqlite3.open_ptr(db_ptr)
    +

    Opens the SQLite database corresponding to the light userdata db_ptr and returns +its handle as userdata. Use db:get_ptr to get +a db_ptr for an open database.

    +

    +

    sqlite3.backup_init

             sqlite3.backup_init(target_db, target_name, source_db, source_name)
    @@ -325,6 +350,16 @@ have been finalized before this function is called. The function returns This function returns nothing.

    +

    db:get_ptr

    +
    +        db:get_ptr()
    +

    Returns a lightuserdata corresponding to the open db. Use with +sqlite3.open_ptr to pass a database connection +between threads. (When using lsqlite3 in a multithreaded environment, each thread has a separate +Lua environment; full userdata structures can't be passed from one thread to another, but this +is possible with lightuserdata.)

    +

    +

    db:commit_hook

             db:commit_hook(func,udata)
    @@ -499,6 +534,17 @@ all subsequent SQL statements are skipped and db:exec() returns at the next opportunity. This function returns nothing.

    +

    db:db_filename

    +
    +        db:db_filename(name)
    +

    This function returns the filename associated with database name of connection +db. The name may be "main" for the main database file, or +the name specified after the AS keyword in an ATTACH statement for an attached database. +If there is no attached database name on the database connection db, +then no value is returned; if database name is a temporary or in-memory database, +then an empty string is returned.

    +

    +

    db:isopen

             db:isopen()
    diff --git a/3rdparty/lsqlite3/lsqlite3-0.9.4-0.rockspec b/3rdparty/lsqlite3/lsqlite3-0.9.4-0.rockspec deleted file mode 100644 index 4d7a2dabb70..00000000000 --- a/3rdparty/lsqlite3/lsqlite3-0.9.4-0.rockspec +++ /dev/null @@ -1,43 +0,0 @@ -package = "lsqlite3" -version = "0.9.4-0" -source = { - url = "http://lua.sqlite.org/index.cgi/zip/lsqlite3_fsl09x.zip?uuid=fsl_9x", - file = "lsqlite3_fsl09x.zip" -} -description = { - summary = "A binding for Lua to the SQLite3 database library", - detailed = [[ - lsqlite3 is a thin wrapper around the public domain SQLite3 database engine. - The lsqlite3 module supports the creation and manipulation of SQLite3 databases. - After a require('lsqlite3') the exported functions are called with prefix sqlite3. - However, most sqlite3 functions are called via an object-oriented interface to - either database or SQL statement objects. - ]], - license = "MIT/X11", - homepage = "http://lua.sqlite.org/" -} -dependencies = { - "lua >= 5.1, < 5.4" -} -external_dependencies = { - SQLITE = { - header = "sqlite3.h" - } -} -build = { - type = "builtin", - modules = { - lsqlite3 = { - sources = { "lsqlite3.c" }, - defines = {'LSQLITE_VERSION="0.9.4"'}, - libraries = { "sqlite3" }, - incdirs = { "$(SQLITE_INCDIR)" }, - libdirs = { "$(SQLITE_LIBDIR)" } - }, - lsqlite3complete = { - sources = { "lsqlite3.c", "sqlite3.c" }, - defines = {'LSQLITE_VERSION="0.9.4"', 'luaopen_lsqlite3=luaopen_lsqlite3complete'} - } - }, - copy_directories = { 'doc', 'examples' } -} diff --git a/3rdparty/lsqlite3/lsqlite3-0.9.5-1.rockspec b/3rdparty/lsqlite3/lsqlite3-0.9.5-1.rockspec new file mode 100644 index 00000000000..b5d2c85df04 --- /dev/null +++ b/3rdparty/lsqlite3/lsqlite3-0.9.5-1.rockspec @@ -0,0 +1,39 @@ +package = "lsqlite3" +version = "0.9.5-1" +source = { + url = "http://lua.sqlite.org/index.cgi/zip/lsqlite3_fsl09y.zip?uuid=fsl_9y", + file = "lsqlite3_fsl09y.zip" +} +description = { + summary = "A binding for Lua to the SQLite3 database library", + detailed = [[ + lsqlite3 is a thin wrapper around the public domain SQLite3 database engine. SQLite3 is + dynamically linked to lsqlite3. The statically linked alternative is lsqlite3complete. + The lsqlite3 module supports the creation and manipulation of SQLite3 databases. + Most sqlite3 functions are called via an object-oriented interface to either + database or SQL statement objects. + ]], + license = "MIT", + homepage = "http://lua.sqlite.org/" +} +dependencies = { + "lua >= 5.1, < 5.5" +} +external_dependencies = { + SQLITE = { + header = "sqlite3.h" + } +} +build = { + type = "builtin", + modules = { + lsqlite3 = { + sources = { "lsqlite3.c" }, + defines = {'LSQLITE_VERSION="0.9.5"'}, + libraries = { "sqlite3" }, + incdirs = { "$(SQLITE_INCDIR)" }, + libdirs = { "$(SQLITE_LIBDIR)" } + }, + }, + copy_directories = { 'doc', 'examples' } +} diff --git a/3rdparty/lsqlite3/lsqlite3.c b/3rdparty/lsqlite3/lsqlite3.c index 483bbf8deae..8688c6e09d7 100644 --- a/3rdparty/lsqlite3/lsqlite3.c +++ b/3rdparty/lsqlite3/lsqlite3.c @@ -31,18 +31,20 @@ #include #define LUA_LIB -#include -#include +#include "lua.h" +#include "lauxlib.h" #if LUA_VERSION_NUM > 501 /* ** Lua 5.2 */ -//#define lua_strlen lua_rawlen +#ifndef lua_strlen +#define lua_strlen lua_rawlen +#endif /* luaL_typerror always used with arg at ndx == NULL */ #define luaL_typerror(L,ndx,str) luaL_error(L,"bad argument %d (%s expected, got nil)",ndx,str) /* luaL_register used once, so below expansion is OK for this case */ -//#define luaL_register(L,name,reg) lua_newtable(L);luaL_setfuncs(L,reg,0) +#define luaL_register(L,name,reg) lua_newtable(L);luaL_setfuncs(L,reg,0) /* luaL_openlib always used with name == NULL */ #define luaL_openlib(L,name,reg,nup) luaL_setfuncs(L,reg,nup) @@ -54,7 +56,7 @@ #endif #endif -#include +#include "sqlite3.h" /* compile time features */ #if !defined(SQLITE_OMIT_PROGRESS_CALLBACK) @@ -930,6 +932,14 @@ static int db_interrupt(lua_State *L) { return 0; } +static int db_db_filename(lua_State *L) { + sdb *db = lsqlite_checkdb(L, 1); + const char *db_name = luaL_checkstring(L, 2); + // sqlite3_db_filename may return NULL, in that case Lua pushes nil... + lua_pushstring(L, sqlite3_db_filename(db->db, db_name)); + return 1; +} + /* ** Registering SQL functions: */ @@ -1171,7 +1181,7 @@ static int collwrapper(scc *co,int l1,const void *p1, lua_rawgeti(L,LUA_REGISTRYINDEX,co->ref); lua_pushlstring(L,p1,l1); lua_pushlstring(L,p2,l2); - if (lua_pcall(L,2,1,0)==0) res=lua_tonumber(L,-1); + if (lua_pcall(L,2,1,0)==0) res=(int)lua_tonumber(L,-1); lua_pop(L,1); return res; } @@ -1307,7 +1317,7 @@ static void db_update_hook_callback(void *user, int op, char const *dbname, char sdb *db = (sdb*)user; lua_State *L = db->L; int top = lua_gettop(L); - //lua_Number n; + lua_Number n; /* setup lua callback call */ lua_rawgeti(L, LUA_REGISTRYINDEX, db->update_hook_cb); /* get callback */ @@ -2005,6 +2015,17 @@ static int db_close_vm(lua_State *L) { return 0; } +/* From: Wolfgang Oertl +When using lsqlite3 in a multithreaded environment, each thread has a separate Lua +environment, but full userdata structures can't be passed from one thread to another. +This is possible with lightuserdata, however. See: lsqlite_open_ptr(). +*/ +static int db_get_ptr(lua_State *L) { + sdb *db = lsqlite_checkdb(L, 1); + lua_pushlightuserdata(L, db->db); + return 1; +} + static int db_gc(lua_State *L) { sdb *db = lsqlite_getdb(L, 1); if (db->db != NULL) /* ignore closed databases */ @@ -2029,7 +2050,7 @@ static int lsqlite_complete(lua_State *L) { return 1; } -#ifndef WIN32 +#ifndef _WIN32 static int lsqlite_temp_directory(lua_State *L) { const char *oldtemp = sqlite3_temp_directory; @@ -2080,6 +2101,30 @@ static int lsqlite_open_memory(lua_State *L) { return lsqlite_do_open(L, ":memory:", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE); } +/* From: Wolfgang Oertl +When using lsqlite3 in a multithreaded environment, each thread has a separate Lua +environment, but full userdata structures can't be passed from one thread to another. +This is possible with lightuserdata, however. See: db_get_ptr(). +*/ +static int lsqlite_open_ptr(lua_State *L) { + sqlite3 *db_ptr; + sdb *db; + int rc; + + luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); + db_ptr = lua_touserdata(L, 1); + /* This is the only API function that runs sqlite3SafetyCheck regardless of + * SQLITE_ENABLE_API_ARMOR and does almost nothing (without an SQL + * statement) */ + rc = sqlite3_exec(db_ptr, NULL, NULL, NULL, NULL); + if (rc != SQLITE_OK) + luaL_argerror(L, 1, "not a valid SQLite3 pointer"); + + db = newdb(L); /* create and leave in stack */ + db->db = db_ptr; + return 1; +} + static int lsqlite_newindex(lua_State *L) { lua_pushliteral(L, "attempt to change readonly table"); lua_error(L); @@ -2188,6 +2233,7 @@ static const luaL_Reg dblib[] = { {"errmsg", db_errmsg }, {"error_message", db_errmsg }, {"interrupt", db_interrupt }, + {"db_filename", db_db_filename }, {"create_function", db_create_function }, {"create_aggregate", db_create_aggregate }, @@ -2213,6 +2259,7 @@ static const luaL_Reg dblib[] = { {"execute", db_exec }, {"close", db_close }, {"close_vm", db_close_vm }, + {"get_ptr", db_get_ptr }, {"__tostring", db_tostring }, {"__gc", db_gc }, @@ -2304,11 +2351,12 @@ static const luaL_Reg sqlitelib[] = { {"lversion", lsqlite_lversion }, {"version", lsqlite_version }, {"complete", lsqlite_complete }, -#ifndef WIN32 +#ifndef _WIN32 {"temp_directory", lsqlite_temp_directory }, #endif {"open", lsqlite_open }, {"open_memory", lsqlite_open_memory }, + {"open_ptr", lsqlite_open_ptr }, {"backup_init", lsqlite_backup_init }, @@ -2329,12 +2377,6 @@ static void create_meta(lua_State *L, const char *name, const luaL_Reg *lib) { lua_pop(L, 1); } -static int luaopen_sqlite3 ( lua_State * L ) -{ - luaL_newlib(L, sqlitelib); - return 1; -} - LUALIB_API int luaopen_lsqlite3(lua_State *L) { create_meta(L, sqlite_meta, dblib); create_meta(L, sqlite_vm_meta, vmlib); @@ -2345,8 +2387,8 @@ LUALIB_API int luaopen_lsqlite3(lua_State *L) { sqlite_ctx_meta_ref = luaL_ref(L, LUA_REGISTRYINDEX); /* register (local) sqlite metatable */ - //luaL_register(L, "sqlite3", sqlitelib); - luaL_requiref(L, "sqlite3", luaopen_sqlite3, 1); + luaL_register(L, "sqlite3", sqlitelib); + { int i = 0; /* add constants to global table */ diff --git a/3rdparty/lsqlite3/lsqlite3complete-0.9.5-1.rockspec b/3rdparty/lsqlite3/lsqlite3complete-0.9.5-1.rockspec new file mode 100644 index 00000000000..c71c6365c11 --- /dev/null +++ b/3rdparty/lsqlite3/lsqlite3complete-0.9.5-1.rockspec @@ -0,0 +1,40 @@ +package = "lsqlite3complete" +version = "0.9.5-1" +source = { + url = "http://lua.sqlite.org/index.cgi/zip/lsqlite3_fsl09y.zip?uuid=fsl_9y", + file = "lsqlite3_fsl09y.zip" +} +description = { + summary = "A binding for Lua to the SQLite3 database library", + detailed = [[ + lsqlite3complete is a thin wrapper around the public domain SQLite3 database engine. + SQLite3 is included and statically linked. (The dynamically linked alternative is lsqlite3). + The lsqlite3complete module supports the creation and manipulation of SQLite3 databases. + Most sqlite3 functions are called via an object-oriented interface to either database + or SQL statement objects. + ]], + license = "MIT", + homepage = "http://lua.sqlite.org/" +} +dependencies = { + "lua >= 5.1, < 5.5" +} +build = { + type = "builtin", + modules = { + lsqlite3complete = { + sources = { "lsqlite3.c", "sqlite3.c" }, + defines = {'LSQLITE_VERSION="0.9.5"', 'luaopen_lsqlite3=luaopen_lsqlite3complete'} + }, + }, + platforms = { + unix = { + modules = { + lsqlite3complete = { + libraries = { "pthread", "m", "dl" } + } + } + } + }, + copy_directories = { 'doc', 'examples' } +} diff --git a/3rdparty/lsqlite3/test/test.lua b/3rdparty/lsqlite3/test/test.lua index e5e3bfa35f2..e94b957a89c 100644 --- a/3rdparty/lsqlite3/test/test.lua +++ b/3rdparty/lsqlite3/test/test.lua @@ -44,7 +44,7 @@ line("select * from t", 'db:exec') assert(db:exec('select * from t', function (ud, ncols, values, names) --table.setn(values, 2) - print(table.unpack(values)) + print((unpack or table.unpack)(values)) return sqlite3.OK end) == sqlite3.OK) diff --git a/3rdparty/lsqlite3/test/tests-sqlite3.lua b/3rdparty/lsqlite3/test/tests-sqlite3.lua index 4a276b0bc29..125ec22b3f6 100644 --- a/3rdparty/lsqlite3/test/tests-sqlite3.lua +++ b/3rdparty/lsqlite3/test/tests-sqlite3.lua @@ -1204,5 +1204,45 @@ function db_bu_null.test() end +-------------------------------------- +-- Functions added 2016-11-xx 0.9.4 -- +-------------------------------------- + +r094 = lunit_TestCase("Functions added 0.9.4") + +function r094.setup() + r094.db = assert( sqlite3.open_memory() ) + r094.filename = "/tmp/__lua-sqlite3-20161112163049." .. os.time() + r094.db_fn = assert_userdata( sqlite3.open(r094.filename) ) +end + +function r094.teardown() + assert_number( r094.db:close() ) + assert_number( r094.db_fn:close() ) +end + +function r094.test_db_filename() + + assert_nil( r094.db:db_filename("frob") ) + assert_equal( '', r094.db:db_filename("main") ) + + assert_nil( r094.db_fn:db_filename("frob") ) + assert_equal( r094.filename, r094.db_fn:db_filename("main") ) + + -- from Wolfgang Oertl + local db_ptr = assert_userdata( r094.db:get_ptr() ) + local db2 = assert_userdata( sqlite3.open_ptr(db_ptr) ) + -- do something via connection 1 + r094.db:exec("CREATE TABLE test1(a, b)") + r094.db:exec("INSERT INTO test1 VALUES(1, 2)") + -- see result via connection 2 + for a, b in db2:urows("SELECT * FROM test1 ORDER BY a") do + assert_equal(a, 1) + assert_equal(b, 2) + end + assert_number( db2:close() ) + +end + lunit.main() diff --git a/3rdparty/lua/Makefile b/3rdparty/lua/Makefile index 119110d2f01..fef1af4821e 100644 --- a/3rdparty/lua/Makefile +++ b/3rdparty/lua/Makefile @@ -4,7 +4,7 @@ # == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT ======================= # Your platform. See PLATS for possible values. -PLAT= none +PLAT= guess # Where to install. The installation starts in the src and doc directories, # so take care if INSTALL_TOP is not an absolute path. See the local target. @@ -36,7 +36,7 @@ RM= rm -f # == END OF USER SETTINGS -- NO NEED TO CHANGE ANYTHING BELOW THIS LINE ======= # Convenience platforms targets. -PLATS= aix bsd c89 freebsd generic linux macosx mingw posix solaris +PLATS= guess aix bsd c89 freebsd generic linux linux-readline macosx mingw posix solaris # What to install. TO_BIN= lua luac @@ -45,17 +45,14 @@ TO_LIB= liblua.a TO_MAN= lua.1 luac.1 # Lua version and release. -V= 5.3 +V= 5.4 R= $V.4 # Targets start here. all: $(PLAT) -$(PLATS) clean: - cd src && $(MAKE) $@ - -test: dummy - src/lua -v +$(PLATS) help test clean: + @cd src && $(MAKE) $@ install: dummy cd src && $(MKDIR) $(INSTALL_BIN) $(INSTALL_INC) $(INSTALL_LIB) $(INSTALL_MAN) $(INSTALL_LMOD) $(INSTALL_CMOD) @@ -73,15 +70,10 @@ uninstall: local: $(MAKE) install INSTALL_TOP=../install -none: - @echo "Please do 'make PLATFORM' where PLATFORM is one of these:" - @echo " $(PLATS)" - @echo "See doc/readme.html for complete instructions." - -# make may get confused with test/ and install/ +# make may get confused with install/ if it does not support .PHONY. dummy: -# echo config parameters +# Echo config parameters. echo: @cd src && $(MAKE) -s echo @echo "PLAT= $(PLAT)" @@ -101,14 +93,14 @@ echo: @echo "INSTALL_EXEC= $(INSTALL_EXEC)" @echo "INSTALL_DATA= $(INSTALL_DATA)" -# echo pkg-config data +# Echo pkg-config data. pc: @echo "version=$R" @echo "prefix=$(INSTALL_TOP)" @echo "libdir=$(INSTALL_LIB)" @echo "includedir=$(INSTALL_INC)" -# list targets that do not create files (but not all makes understand .PHONY) -.PHONY: all $(PLATS) clean test install local none dummy echo pecho lecho +# Targets that do not create files (not all makes understand .PHONY). +.PHONY: all $(PLATS) help test clean install uninstall local dummy echo pc # (end of Makefile) diff --git a/3rdparty/lua/README b/3rdparty/lua/README index 0b31908a06c..c394c69828b 100644 --- a/3rdparty/lua/README +++ b/3rdparty/lua/README @@ -1,5 +1,5 @@ -This is Lua 5.3.4, released on 12 Jan 2017. +This is Lua 5.4.4, released on 13 Jan 2022. For installation instructions, license details, and further information about Lua, see doc/readme.html. diff --git a/3rdparty/lua/doc/contents.html b/3rdparty/lua/doc/contents.html index 445556f9641..ab82eb4a927 100644 --- a/3rdparty/lua/doc/contents.html +++ b/3rdparty/lua/doc/contents.html @@ -1,7 +1,7 @@ -Lua 5.3 Reference Manual - contents +Lua 5.4 Reference Manual - contents @@ -11,7 +11,7 @@

    Lua -Lua 5.3 Reference Manual +Lua 5.4 Reference Manual

    @@ -32,7 +32,7 @@ For a complete introduction to Lua programming, see the book

    -Copyright © 2015–2017 Lua.org, PUC-Rio. +Copyright © 2020–2022 Lua.org, PUC-Rio. Freely available under the terms of the Lua license. @@ -49,8 +49,10 @@ Freely available under the terms of the

  • 2.4 – Metatables and Metamethods
  • 2.5 – Garbage Collection
  • 2.6 – Coroutines @@ -68,6 +70,7 @@ Freely available under the terms of the
  • 3.3.5 – For Statement
  • 3.3.6 – Function Calls as Statements
  • 3.3.7 – Local Declarations +
  • 3.3.8 – To-be-closed Variables
  • 3.4 – Expressions

    -

  • 6 – Standard Libraries +
  • 6 – The Standard Libraries
    • 6.1 – Basic Functions
    • 6.2 – Coroutine Manipulation @@ -126,9 +135,9 @@ Freely available under the terms of the

    • 8 – Incompatibilities with the Previous Version

    • 9 – The Complete Syntax of Lua @@ -165,10 +174,12 @@ Freely available under the terms of the tonumber
      tostring
      type
      +warn
      xpcall

      coroutine
      +coroutine.close
      coroutine.create
      coroutine.isyieldable
      coroutine.resume
      @@ -318,14 +329,46 @@ Freely available under the terms of the utf8.len
      utf8.offset
      +

      metamethods

      +

      +__add
      +__band
      +__bnot
      +__bor
      +__bxor
      +__call
      +__close
      +__concat
      +__div
      +__eq
      +__gc
      +__idiv
      +__index
      +__le
      +__len
      +__lt
      +__metatable
      +__mod
      +__mode
      +__mul
      +__name
      +__newindex
      +__pairs
      +__pow
      +__shl
      +__shr
      +__sub
      +__tostring
      +__unm
      +

      environment
      variables

      LUA_CPATH
      -LUA_CPATH_5_3
      +LUA_CPATH_5_4
      LUA_INIT
      -LUA_INIT_5_3
      +LUA_INIT_5_4
      LUA_PATH
      -LUA_PATH_5_3
      +LUA_PATH_5_4
      @@ -342,6 +385,7 @@ Freely available under the terms of the lua_Reader
      lua_State
      lua_Unsigned
      +lua_WarnFunction
      lua_Writer

      @@ -352,6 +396,7 @@ Freely available under the terms of the lua_callk
      lua_checkstack
      lua_close
      +lua_closeslot
      lua_compare
      lua_concat
      lua_copy
      @@ -368,13 +413,13 @@ Freely available under the terms of the lua_gethookmask
      lua_geti
      lua_getinfo
      +lua_getiuservalue
      lua_getlocal
      lua_getmetatable
      lua_getstack
      lua_gettable
      lua_gettop
      lua_getupvalue
      -lua_getuservalue
      lua_insert
      lua_isboolean
      lua_iscfunction
      @@ -395,7 +440,7 @@ Freely available under the terms of the lua_newstate
      lua_newtable
      lua_newthread
      -lua_newuserdata
      +lua_newuserdatauv
      lua_next
      lua_numbertointeger
      lua_pcall
      @@ -427,6 +472,7 @@ Freely available under the terms of the lua_register
      lua_remove
      lua_replace
      +lua_resetthread
      lua_resume
      lua_rotate
      lua_setallocf
      @@ -434,16 +480,18 @@ Freely available under the terms of the lua_setglobal
      lua_sethook
      lua_seti
      +lua_setiuservalue
      lua_setlocal
      lua_setmetatable
      lua_settable
      lua_settop
      lua_setupvalue
      -lua_setuservalue
      +lua_setwarnf
      lua_status
      lua_stringtonumber
      lua_toboolean
      lua_tocfunction
      +lua_toclose
      lua_tointeger
      lua_tointegerx
      lua_tolstring
      @@ -459,6 +507,7 @@ Freely available under the terms of the lua_upvalueindex
      lua_upvaluejoin
      lua_version
      +lua_warning
      lua_xmove
      lua_yield
      lua_yieldk
      @@ -473,14 +522,19 @@ Freely available under the terms of the

      luaL_addchar
      +luaL_addgsub
      luaL_addlstring
      luaL_addsize
      luaL_addstring
      luaL_addvalue
      luaL_argcheck
      luaL_argerror
      +luaL_argexpected
      +luaL_buffaddr
      luaL_buffinit
      luaL_buffinitsize
      +luaL_bufflen
      +luaL_buffsub
      luaL_callmeta
      luaL_checkany
      luaL_checkinteger
      @@ -519,6 +573,7 @@ Freely available under the terms of the luaL_optstring
      luaL_prepbuffer
      luaL_prepbuffsize
      +luaL_pushfail
      luaL_pushresult
      luaL_pushresultsize
      luaL_ref
      @@ -528,6 +583,7 @@ Freely available under the terms of the luaL_testudata
      luaL_tolstring
      luaL_traceback
      +luaL_typeerror
      luaL_typename
      luaL_unref
      luaL_where
      @@ -549,7 +605,6 @@ Freely available under the terms of the

      LUA_ERRERR
      LUA_ERRFILE
      -LUA_ERRGCMM
      LUA_ERRMEM
      LUA_ERRRUN
      LUA_ERRSYNTAX
      @@ -558,6 +613,7 @@ Freely available under the terms of the LUA_HOOKLINE
      LUA_HOOKRET
      LUA_HOOKTAILCALL
      +LUAL_BUFFERSIZE
      LUA_MASKCALL
      LUA_MASKCOUNT
      LUA_MASKLINE
      @@ -601,7 +657,6 @@ Freely available under the terms of the LUA_TUSERDATA
      LUA_USE_APICHECK
      LUA_YIELD
      -LUAL_BUFFERSIZE
      @@ -609,10 +664,10 @@ Freely available under the terms of the

      diff --git a/3rdparty/lua/doc/lua.1 b/3rdparty/lua/doc/lua.1 index d728d0b80c1..a46a1a67dd0 100644 --- a/3rdparty/lua/doc/lua.1 +++ b/3rdparty/lua/doc/lua.1 @@ -1,5 +1,5 @@ -.\" $Id: lua.man,v 1.14 2016/10/17 15:43:50 lhf Exp $ -.TH LUA 1 "$Date: 2016/10/17 15:43:50 $" +.\" $Id: lua.man,v 1.14 2020/05/21 19:31:21 lhf Exp $ +.TH LUA 1 "$Date: 2020/05/21 19:31:21 $" .SH NAME lua \- Lua interpreter .SH SYNOPSIS @@ -25,52 +25,57 @@ the Lua compiler.) .B lua can be used as a batch interpreter and also interactively. .LP -The given -.I options -are handled in order and then +After handling the +.IR options , the Lua program in file .I script is loaded and executed. -The given +The .I args are available to .I script as strings in a global table named -.BR arg . -If no options or arguments are given, -then -.B "\-v \-i" -is assumed when the standard input is a terminal; -otherwise, -.B "\-" -is assumed. +.B arg +and also as arguments to its main function. +When called without arguments, +.B lua +behaves as +.B "lua \-v \-i" +if the standard input is a terminal, +and as +.B "lua \-" +otherwise. .LP In interactive mode, .B lua prompts the user, reads lines from the standard input, and executes them as they are read. -If the line contains an expression or list of expressions, -then the line is evaluated and the results are printed. +If the line contains an expression, +then the line is evaluated and the result is printed. If a line does not contain a complete statement, then a secondary prompt is displayed and lines are read until a complete statement is formed or a syntax error is found. .LP -At the very start, -before even handling the command line, +Before handling command line options and scripts, .B lua checks the contents of the environment variables -.B LUA_INIT_5_3 -or +.B LUA_INIT_5_4 +and .BR LUA_INIT , in that order. -If the contents is of the form +If the contents are of the form .RI '@ filename ', then .I filename is executed. -Otherwise, the string is assumed to be a Lua statement and is executed. +Otherwise, the contents are assumed to be a Lua statement and is executed. +When +.B LUA_INIT_5_4 +is defined, +.B LUA_INIT +is ignored. .SH OPTIONS .TP .BI \-e " stat" @@ -82,10 +87,10 @@ enter interactive mode after executing .IR script . .TP .BI \-l " name" -execute the equivalent of -.IB name =require(' name ') -before executing -.IR script . +require library +.I name +into global +.IR name . .TP .B \-v show version information. @@ -93,18 +98,50 @@ show version information. .B \-E ignore environment variables. .TP +.B \-W +turn warnings on. +.TP .B \-\- stop handling options. .TP .B \- stop handling options and execute the standard input as a file. +.SH ENVIRONMENT VARIABLES +The following environment variables affect the execution of +.BR lua . +When defined, +the version-specific variants take priority +and the version-neutral variants are ignored. +.TP +.B LUA_INIT, LUA_INIT_5_4 +Code to be executed before command line options and scripts. +.TP +.B LUA_PATH, LUA_PATH_5_4 +Initial value of package.cpath, +the path used by require to search for Lua loaders. +.TP +.B LUA_CPATH, LUA_CPATH_5_4 +Initial value of package.cpath, +the path used by require to search for C loaders. +.SH EXIT STATUS +If a script calls os.exit, +then +.B lua +exits with the given exit status. +Otherwise, +.B lua +exits +with EXIT_SUCCESS (0 on POSIX systems) if there were no errors +and +with EXIT_FAILURE (1 on POSIX systems) if there were errors. +Errors raised in interactive mode do not cause exits. +.SH DIAGNOSTICS +Error messages should be self explanatory. .SH "SEE ALSO" .BR luac (1) .br The documentation at lua.org, especially section 7 of the reference manual. -.SH DIAGNOSTICS -Error messages should be self explanatory. .SH AUTHORS R. Ierusalimschy, L. H. de Figueiredo, diff --git a/3rdparty/lua/doc/lua.css b/3rdparty/lua/doc/lua.css index 5bedf7eb898..cbd0799d152 100644 --- a/3rdparty/lua/doc/lua.css +++ b/3rdparty/lua/doc/lua.css @@ -10,7 +10,7 @@ body { line-height: 1.25 ; margin: 16px auto ; padding: 32px ; - border: solid #a0a0a0 1px ; + border: solid #ccc 1px ; border-radius: 20px ; max-width: 70em ; width: 90% ; @@ -111,36 +111,29 @@ pre.session { border-radius: 8px ; } -td.gutter { - width: 4% ; -} - -table.columns { +table { border: none ; border-spacing: 0 ; border-collapse: collapse ; } -table.columns td { - vertical-align: top ; +td { padding: 0 ; - padding-bottom: 1em ; - text-align: justify ; - line-height: 1.25 ; + margin: 0 ; } -p.logos a:link:hover, p.logos a:visited:hover { - background-color: inherit ; +td.gutter { + width: 4% ; } -table.book { - border: none ; - border-spacing: 0 ; - border-collapse: collapse ; +table.columns td { + vertical-align: top ; + padding-bottom: 1em ; + text-align: justify ; + line-height: 1.25 ; } table.book td { - padding: 0 ; vertical-align: top ; } @@ -159,6 +152,10 @@ table.book span { margin-top: 0.25em ; } +p.logos a:link:hover, p.logos a:visited:hover { + background-color: inherit ; +} + img { background-color: white ; } diff --git a/3rdparty/lua/doc/manual.html b/3rdparty/lua/doc/manual.html index 3126b5d6afb..61a8220d7fd 100644 --- a/3rdparty/lua/doc/manual.html +++ b/3rdparty/lua/doc/manual.html @@ -1,7 +1,7 @@ -Lua 5.3 Reference Manual +Lua 5.4 Reference Manual @@ -11,7 +11,7 @@

      Lua -Lua 5.3 Reference Manual +Lua 5.4 Reference Manual

      @@ -19,7 +19,7 @@ by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes

      -Copyright © 2015–2017 Lua.org, PUC-Rio. +Copyright © 2020–2022 Lua.org, PUC-Rio. Freely available under the terms of the Lua license. @@ -35,7 +35,7 @@ Freely available under the terms of the

      - + @@ -56,7 +56,7 @@ Lua is dynamically typed, runs by interpreting bytecode with a register-based virtual machine, and has automatic memory management with -incremental garbage collection, +a generational garbage collection, making it ideal for configuration, scripting, and rapid prototyping. @@ -106,15 +106,19 @@ see Roberto's book, Programming in Lua.

      2 – Basic Concepts

      + +

      This section describes the basic concepts of the language. + +

      2.1 – Values and Types

      -Lua is a dynamically typed language. +Lua is a dynamically typed language. This means that variables do not have types; only values do. There are no type definitions in the language. @@ -122,7 +126,7 @@ All values carry their own type.

      -All values in Lua are first-class values. +All values in Lua are first-class values. This means that all values can be stored in variables, passed as arguments to other functions, and returned as results. @@ -134,31 +138,22 @@ There are eight basic types in Lua: thread, and table. The type nil has one single value, nil, whose main property is to be different from any other value; -it usually represents the absence of a useful value. +it often represents the absence of a useful value. The type boolean has two values, false and true. Both nil and false make a condition false; -any other value makes it true. -The type number represents both -integer numbers and real (floating-point) numbers. -The type string represents immutable sequences of bytes. - -Lua is 8-bit clean: -strings can contain any 8-bit value, -including embedded zeros ('\0'). -Lua is also encoding-agnostic; -it makes no assumptions about the contents of a string. +they are collectively called false values. +Any other value makes a condition true. +Despite its name, +false is frequently used as an alternative to nil, +with the key difference that false behaves +like a regular value in a table, +while a nil in a table represents an absent key.

      -The type number uses two internal representations, -or two subtypes, -one called integer and the other called float. -Lua has explicit rules about when each representation is used, -but it also converts between them automatically as needed (see §3.4.3). -Therefore, -the programmer may choose to mostly ignore the difference -between integers and floats -or to assume complete control over the representation of each number. +The type number represents both +integer numbers and real (floating-point) numbers, +using two subtypes: integer and float. Standard Lua uses 64-bit integers and double-precision (64-bit) floats, but you can also compile Lua so that it uses 32-bit integers and/or single-precision (32-bit) floats. @@ -168,6 +163,36 @@ for small machines and embedded systems. (See macro LUA_32BITS in file luaconf.h.) +

      +Unless stated otherwise, +any overflow when manipulating integer values wrap around, +according to the usual rules of two-complement arithmetic. +(In other words, +the actual result is the unique representable integer +that is equal modulo 2n to the mathematical result, +where n is the number of bits of the integer type.) + + +

      +Lua has explicit rules about when each subtype is used, +but it also converts between them automatically as needed (see §3.4.3). +Therefore, +the programmer may choose to mostly ignore the difference +between integers and floats +or to assume complete control over the representation of each number. + + +

      +The type string represents immutable sequences of bytes. + +Lua is 8-bit clean: +strings can contain any 8-bit value, +including embedded zeros ('\0'). +Lua is also encoding-agnostic; +it makes no assumptions about the contents of a string. +The length of any string in Lua must fit in a Lua integer. + +

      Lua can call (and manipulate) functions written in Lua and functions written in C (see §3.4.10). @@ -190,7 +215,8 @@ the programmer can define operations for full userdata values (see §2.4). Userdata values cannot be created or modified in Lua, only through the C API. -This guarantees the integrity of data owned by the host program. +This guarantees the integrity of data owned by +the host program and C libraries.

      @@ -203,13 +229,14 @@ even those that do not support threads natively.

      The type table implements associative arrays, -that is, arrays that can be indexed not only with numbers, -but with any Lua value except nil and NaN. -(Not a Number is a special value used to represent -undefined or unrepresentable numerical results, such as 0/0.) +that is, arrays that can have as indices not only numbers, +but any Lua value except nil and NaN. +(Not a Number is a special floating-point value +used by the IEEE 754 standard to represent +undefined numerical results, such as 0/0.) Tables can be heterogeneous; that is, they can contain values of all types (except nil). -Any key with value nil is not considered part of the table. +Any key associated to the value nil is not considered part of the table. Conversely, any key that is not part of a table has an associated value nil. @@ -245,14 +272,10 @@ In particular, floats with integral values are equal to their respective integers (e.g., 1.0 == 1). To avoid ambiguities, -any float with integral value used as a key -is converted to its respective integer. +any float used as a key that is equal to an integer +is converted to that integer. For instance, if you write a[2.0] = true, -the actual key inserted into the table will be the -integer 2. -(On the other hand, -2 and "2" are different Lua values and therefore -denote different table entries.) +the actual key inserted into the table will be the integer 2.

      @@ -266,7 +289,7 @@ these operations do not imply any kind of copy.

      The library function type returns a string describing the type -of a given value (see §6.1). +of a given value (see type). @@ -275,7 +298,7 @@ of a given value (see §6.1).

      2.2 – Environments and the Global Environment

      -As will be discussed in §3.2 and §3.3.3, +As we will discuss further in §3.2 and §3.3.3, any reference to a free name (that is, a name not bound to any declaration) var is syntactically translated to _ENV.var. @@ -301,24 +324,25 @@ Any table used as the value of _ENV is called an environment Lua keeps a distinguished environment called the global environment. -This value is kept at a special index in the C registry (see §4.5). +This value is kept at a special index in the C registry (see §4.3). In Lua, the global variable _G is initialized with this same value. -(_G is never used internally.) +(_G is never used internally, +so changing its value will affect only your own code.)

      When Lua loads a chunk, -the default value for its _ENV upvalue +the default value for its _ENV variable is the global environment (see load). Therefore, by default, free names in Lua code refer to entries in the global environment -(and, therefore, they are also called global variables). +and, therefore, they are also called global variables. Moreover, all standard libraries are loaded in the global environment and some functions there operate on that environment. You can use load (or loadfile) to load a chunk with a different environment. (In C, you have to load the chunk and then change the value -of its first upvalue.) +of its first upvalue; see lua_setupvalue.) @@ -326,39 +350,57 @@ of its first upvalue.)

      2.3 – Error Handling

      +

      +Several operations in Lua can raise an error. +An error interrupts the normal flow of the program, +which can continue by catching the error. + + +

      +Lua code can explicitly raise an error by calling the +error function. +(This function never returns.) + + +

      +To catch errors in Lua, +you can do a protected call, +using pcall (or xpcall). +The function pcall calls a given function in protected mode. +Any error while running the function stops its execution, +and control returns immediately to pcall, +which returns a status code. + +

      Because Lua is an embedded extension language, -all Lua actions start from C code in the host program -calling a function from the Lua library. +Lua code starts running by a call +from C code in the host program. (When you use Lua standalone, the lua application is the host program.) -Whenever an error occurs during +Usually, this call is protected; +so, when an otherwise unprotected error occurs during the compilation or execution of a Lua chunk, control returns to the host, -which can take appropriate measures -(such as printing an error message). - - -

      -Lua code can explicitly generate an error by calling the -error function. -If you need to catch errors in Lua, -you can use pcall or xpcall -to call a given function in protected mode. +which can take appropriate measures, +such as printing an error message.

      Whenever there is an error, -an error object (also called an error message) +an error object is propagated with information about the error. Lua itself only generates errors whose error object is a string, but programs may generate errors with any value as the error object. It is up to the Lua program or its host to handle such error objects. +For historical reasons, +an error object is often called an error message, +even though it does not have to be a string.

      -When you use xpcall or lua_pcall, +When you use xpcall (or lua_pcall, in C) you may give a message handler to be called in case of errors. This function is called with the original error object @@ -371,9 +413,17 @@ so, an error inside the message handler will call the message handler again. If this loop goes on for too long, Lua breaks it and returns an appropriate message. -(The message handler is called only for regular runtime errors. +The message handler is called only for regular runtime errors. It is not called for memory-allocation errors -nor for errors while running finalizers.) +nor for errors while running finalizers or other message handlers. + + +

      +Lua also offers a system of warnings (see warn). +Unlike errors, warnings do not interfere +in any way with program execution. +They typically only generate a message to the user, +although this behavior can be adapted from C (see lua_setwarnf). @@ -385,11 +435,11 @@ nor for errors while running finalizers.) Every value in Lua can have a metatable. This metatable is an ordinary Lua table that defines the behavior of the original value -under certain special operations. +under certain events. You can change several aspects of the behavior -of operations over a value by setting specific fields in its metatable. +of a value by setting specific fields in its metatable. For instance, when a non-numeric value is the operand of an addition, -Lua checks for a function in the field "__add" of the value's metatable. +Lua checks for a function in the field __add of the value's metatable. If it finds one, Lua calls this function to perform the addition. @@ -397,33 +447,32 @@ Lua calls this function to perform the addition.

      The key for each event in a metatable is a string with the event name prefixed by two underscores; -the corresponding values are called metamethods. -In the previous example, the key is "__add" +the corresponding value is called a metavalue. +For most events, the metavalue must be a function, +which is then called a metamethod. +In the previous example, the key is the string "__add" and the metamethod is the function that performs the addition. +Unless stated otherwise, +a metamethod may in fact be any callable value, +which is either a function or a value with a __call metamethod.

      You can query the metatable of any value using the getmetatable function. Lua queries metamethods in metatables using a raw access (see rawget). -So, to retrieve the metamethod for event ev in object o, -Lua does the equivalent to the following code: -

      -     rawget(getmetatable(o) or {}, "__ev")
      -

      You can replace the metatable of tables using the setmetatable function. -You cannot change the metatable of other types from Lua code -(except by using the debug library (§6.10)); -you should use the C API for that. +You cannot change the metatable of other types from Lua code, +except by using the debug library (§6.10).

      -Tables and full userdata have individual metatables -(although multiple tables and userdata can share their metatables). +Tables and full userdata have individual metatables, +although multiple tables and userdata can share their metatables. Values of all other types share one single metatable per type; that is, there is one single metatable for all numbers, one for all strings, etc. @@ -432,26 +481,10 @@ but the string library sets a metatable for the string type (see

      -A metatable controls how an object behaves in -arithmetic operations, bitwise operations, -order comparisons, concatenation, length operation, calls, and indexing. -A metatable also can define a function to be called -when a userdata or a table is garbage collected (§2.5). - - -

      -For the unary operators (negation, length, and bitwise NOT), -the metamethod is computed and called with a dummy second operand, -equal to the first one. -This extra operand is only to simplify Lua's internals -(by making these operators behave like a binary operation) -and may be removed in future versions. -(For most uses this extra operand is irrelevant.) - - -

      -A detailed list of events controlled by metatables is given next. -Each operation is identified by its corresponding key. +A detailed list of operations controlled by metatables is given next. +Each event is identified by its corresponding key. +By convention, all metatable keys used by Lua are composed by +two underscores followed by lowercase Latin letters. @@ -459,19 +492,18 @@ Each operation is identified by its corresponding key.

    • __add: the addition (+) operation. -If any operand for an addition is not a number -(nor a string coercible to a number), +If any operand for an addition is not a number, Lua will try to call a metamethod. -First, Lua will check the first operand (even if it is valid). -If that operand does not define a metamethod for __add, +It starts by checking the first operand (even if it is a number); +if that operand does not define a metamethod for __add, then Lua will check the second operand. If Lua can find a metamethod, it calls the metamethod with the two operands as arguments, and the result of the call (adjusted to one value) is the result of the operation. -Otherwise, -it raises an error. +Otherwise, if no metamethod is found, +Lua raises an error.
    • __sub: @@ -514,7 +546,7 @@ the bitwise AND (&) operation. Behavior similar to the addition operation, except that Lua will try a metamethod if any operand is neither an integer -nor a value coercible to an integer (see §3.4.3). +nor a float coercible to an integer (see §3.4.3).
    • __bor: @@ -578,43 +610,33 @@ the less than (<) operation. Behavior similar to the addition operation, except that Lua will try a metamethod only when the values being compared are neither both numbers nor both strings. -The result of the call is always converted to a boolean. +Moreover, the result of the call is always converted to a boolean.
    • __le: the less equal (<=) operation. -Unlike other operations, -the less-equal operation can use two different events. -First, Lua looks for the __le metamethod in both operands, -like in the less than operation. -If it cannot find such a metamethod, -then it will try the __lt metamethod, -assuming that a <= b is equivalent to not (b < a). -As with the other comparison operators, -the result is always a boolean. -(This use of the __lt event can be removed in future versions; -it is also slower than a real __le metamethod.) +Behavior similar to the less than operation.
    • __index: -The indexing access table[key]. +The indexing access operation table[key]. This event happens when table is not a table or when key is not present in table. -The metamethod is looked up in table. +The metavalue is looked up in the metatable of table.

      -Despite the name, -the metamethod for this event can be either a function or a table. +The metavalue for this event can be either a function, a table, +or any value with an __index metavalue. If it is a function, it is called with table and key as arguments, and the result of the call (adjusted to one value) is the result of the operation. -If it is a table, -the final result is the result of indexing this table with key. -(This indexing is regular, not raw, -and therefore can trigger another metamethod.) +Otherwise, +the final result is the result of indexing this metavalue with key. +This indexing is regular, not raw, +and therefore can trigger another __index metavalue.

    • __newindex: @@ -622,26 +644,28 @@ The indexing assignment table[key] = value. Like the index event, this event happens when table is not a table or when key is not present in table. -The metamethod is looked up in table. +The metavalue is looked up in the metatable of table.

      Like with indexing, -the metamethod for this event can be either a function or a table. +the metavalue for this event can be either a function, a table, +or any value with an __newindex metavalue. If it is a function, it is called with table, key, and value as arguments. -If it is a table, -Lua does an indexing assignment to this table with the same key and value. -(This assignment is regular, not raw, -and therefore can trigger another metamethod.) +Otherwise, +Lua repeats the indexing assignment over this metavalue +with the same key and value. +This assignment is regular, not raw, +and therefore can trigger another __newindex metavalue.

      -Whenever there is a __newindex metamethod, +Whenever a __newindex metavalue is invoked, Lua does not perform the primitive assignment. -(If necessary, +If needed, the metamethod itself can call rawset -to do the assignment.) +to do the assignment.

    • __call: @@ -653,17 +677,32 @@ If present, the metamethod is called with func as its first argument, followed by the arguments of the original call (args). All results of the call -are the result of the operation. -(This is the only metamethod that allows multiple results.) +are the results of the operation. +This is the only metamethod that allows multiple results.

    -It is a good practice to add all needed metamethods to a table -before setting it as a metatable of some object. -In particular, the __gc metamethod works only when this order -is followed (see §2.5.1). +In addition to the previous list, +the interpreter also respects the following keys in metatables: +__gc (see §2.5.3), +__close (see §3.3.8), +__mode (see §2.5.4), +and __name. +(The entry __name, +when it contains a string, +may be used by tostring and in error messages.) + + +

    +For the unary operators (negation, length, and bitwise NOT), +the metamethod is computed and called with a dummy second operand, +equal to the first one. +This extra operand is only to simplify Lua's internals +(by making these operators behave like a binary operation) +and may be removed in future versions. +For most uses this extra operand is irrelevant.

    @@ -675,86 +714,191 @@ Some functions in the standard library use other fields in metatables for their own purposes. +

    +It is a good practice to add all needed metamethods to a table +before setting it as a metatable of some object. +In particular, the __gc metamethod works only when this order +is followed (see §2.5.3). +It is also a good practice to set the metatable of an object +right after its creation. + +

    2.5 – Garbage Collection

    + +

    Lua performs automatic memory management. This means that you do not have to worry about allocating memory for new objects or freeing it when the objects are no longer needed. Lua manages memory automatically by running -a garbage collector to collect all dead objects -(that is, objects that are no longer accessible from Lua). +a garbage collector to collect all dead objects. All memory used by Lua is subject to automatic management: strings, tables, userdata, functions, threads, internal structures, etc.

    -Lua implements an incremental mark-and-sweep collector. -It uses two numbers to control its garbage-collection cycles: -the garbage-collector pause and -the garbage-collector step multiplier. -Both use percentage points as units -(e.g., a value of 100 means an internal value of 1). +An object is considered dead +as soon as the collector can be sure the object +will not be accessed again in the normal execution of the program. +("Normal execution" here excludes finalizers, +which can resurrect dead objects (see §2.5.3), +and excludes also operations using the debug library.) +Note that the time when the collector can be sure that an object +is dead may not coincide with the programmer's expectations. +The only guarantees are that Lua will not collect an object +that may still be accessed in the normal execution of the program, +and it will eventually collect an object +that is inaccessible from Lua. +(Here, +inaccessible from Lua means that neither a variable nor +another live object refer to the object.) +Because Lua has no knowledge about C code, +it never collects objects accessible through the registry (see §4.3), +which includes the global environment (see §2.2). + + +

    +The garbage collector (GC) in Lua can work in two modes: +incremental and generational. + + +

    +The default GC mode with the default parameters +are adequate for most uses. +However, programs that waste a large proportion of their time +allocating and freeing memory can benefit from other settings. +Keep in mind that the GC behavior is non-portable +both across platforms and across different Lua releases; +therefore, optimal settings are also non-portable. + + +

    +You can change the GC mode and parameters by calling +lua_gc in C +or collectgarbage in Lua. +You can also use these functions to control +the collector directly (e.g., to stop and restart it). + + + + + +

    2.5.1 – Incremental Garbage Collection

    + +

    +In incremental mode, +each GC cycle performs a mark-and-sweep collection in small steps +interleaved with the program's execution. +In this mode, +the collector uses three numbers to control its garbage-collection cycles: +the garbage-collector pause, +the garbage-collector step multiplier, +and the garbage-collector step size.

    The garbage-collector pause controls how long the collector waits before starting a new cycle. +The collector starts a new cycle when the use of memory +hits n% of the use after the previous collection. Larger values make the collector less aggressive. -Values smaller than 100 mean the collector will not wait to +Values equal to or less than 100 mean the collector will not wait to start a new cycle. A value of 200 means that the collector waits for the total memory in use to double before starting a new cycle. +The default value is 200; the maximum value is 1000.

    The garbage-collector step multiplier -controls the relative speed of the collector relative to -memory allocation. +controls the speed of the collector relative to +memory allocation, +that is, +how many elements it marks or sweeps for each +kilobyte of memory allocated. Larger values make the collector more aggressive but also increase the size of each incremental step. -You should not use values smaller than 100, +You should not use values less than 100, because they make the collector too slow and can result in the collector never finishing a cycle. -The default is 200, -which means that the collector runs at "twice" -the speed of memory allocation. +The default value is 100; the maximum value is 1000. + + +

    +The garbage-collector step size controls the +size of each incremental step, +specifically how many bytes the interpreter allocates +before performing a step. +This parameter is logarithmic: +A value of n means the interpreter will allocate 2n +bytes between steps and perform equivalent work during the step. +A large value (e.g., 60) makes the collector a stop-the-world +(non-incremental) collector. +The default value is 13, +which means steps of approximately 8 Kbytes. + + + +

    2.5.2 – Generational Garbage Collection

    +

    -If you set the step multiplier to a very large number -(larger than 10% of the maximum number of -bytes that the program may use), -the collector behaves like a stop-the-world collector. -If you then set the pause to 200, -the collector behaves as in old Lua versions, -doing a complete collection every time Lua doubles its -memory usage. +In generational mode, +the collector does frequent minor collections, +which traverses only objects recently created. +If after a minor collection the use of memory is still above a limit, +the collector does a stop-the-world major collection, +which traverses all objects. +The generational mode uses two parameters: +the minor multiplier and the the major multiplier.

    -You can change these numbers by calling lua_gc in C -or collectgarbage in Lua. -You can also use these functions to control -the collector directly (e.g., stop and restart it). +The minor multiplier controls the frequency of minor collections. +For a minor multiplier x, +a new minor collection will be done when memory +grows x% larger than the memory in use after the previous major +collection. +For instance, for a multiplier of 20, +the collector will do a minor collection when the use of memory +gets 20% larger than the use after the previous major collection. +The default value is 20; the maximum value is 200. +

    +The major multiplier controls the frequency of major collections. +For a major multiplier x, +a new major collection will be done when memory +grows x% larger than the memory in use after the previous major +collection. +For instance, for a multiplier of 100, +the collector will do a major collection when the use of memory +gets larger than twice the use after the previous collection. +The default value is 100; the maximum value is 1000. -

    2.5.1 – Garbage-Collection Metamethods

    + + + + +

    2.5.3 – Garbage-Collection Metamethods

    You can set garbage-collector metamethods for tables and, using the C API, for full userdata (see §2.4). -These metamethods are also called finalizers. +These metamethods, called finalizers, +are called when the garbage collector detects that the +corresponding table or userdata is dead. Finalizers allow you to coordinate Lua's garbage collection -with external resource management -(such as closing files, network or database connections, -or freeing your own memory). +with external resource management such as closing files, +network or database connections, +or freeing your own memory.

    @@ -762,29 +906,27 @@ For an object (table or userdata) to be finalized when collected, you must mark it for finalization. You mark an object for finalization when you set its metatable -and the metatable has a field indexed by the string "__gc". +and the metatable has a __gc metamethod. Note that if you set a metatable without a __gc field and later create that field in the metatable, the object will not be marked for finalization.

    -When a marked object becomes garbage, +When a marked object becomes dead, it is not collected immediately by the garbage collector. Instead, Lua puts it in a list. After the collection, Lua goes through that list. For each object in the list, it checks the object's __gc metamethod: -If it is a function, -Lua calls it with the object as its single argument; -if the metamethod is not a function, -Lua simply ignores it. +If it is present, +Lua calls it with the object as its single argument.

    At the end of each garbage-collection cycle, -the finalizers for objects are called in +the finalizers are called in the reverse order that the objects were marked for finalization, among those collected in that cycle; that is, the first finalizer to be called is the one associated @@ -804,10 +946,10 @@ However, if the finalizer stores the object in some global place then the resurrection is permanent. Moreover, if the finalizer marks a finalizing object for finalization again, its finalizer will be called again in the next cycle where the -object is unreachable. +object is dead. In any case, the object memory is freed only in a GC cycle where -the object is unreachable and not marked for finalization. +the object is dead and not marked for finalization.

    @@ -818,10 +960,23 @@ If any finalizer marks objects for collection during that phase, these marks have no effect. +

    +Finalizers cannot yield nor run the garbage collector. +Because they can run in unpredictable times, +it is good practice to restrict each finalizer +to the minimum necessary to properly release +its associated resource. + + +

    +Any error while running a finalizer generates a warning; +the error is not propagated. + + -

    2.5.2 – Weak Tables

    +

    2.5.4 – Weak Tables

    A weak table is a table whose elements are @@ -842,10 +997,10 @@ In any case, if either the key or the value is collected, the whole pair is removed from the table. The weakness of a table is controlled by the __mode field of its metatable. -If the __mode field is a string containing the character 'k', -the keys in the table are weak. -If __mode contains 'v', -the values in the table are weak. +This metavalue, if present, must be one of the following strings: +"k", for a table with weak keys; +"v", for a table with weak values; +or "kv", for a table with both weak keys and values.

    @@ -874,8 +1029,10 @@ are not subject to garbage collection, and therefore are not removed from weak tables (unless their associated values are collected). Although strings are subject to garbage collection, -they do not have an explicit construction, -and therefore are not removed from weak tables. +they do not have an explicit construction and +their equality is by value; +they behave more like values than like objects. +Therefore, they are not removed from weak tables.

    @@ -942,7 +1099,10 @@ In case of normal termination, coroutine.resume returns true, plus any values returned by the coroutine main function. In case of errors, coroutine.resume returns false -plus an error object. +plus the error object. +In this case, the coroutine does not unwind its stack, +so that it is possible to inspect it after the error +with the debug API.

    @@ -970,8 +1130,10 @@ go as extra arguments to coroutine.resume< coroutine.wrap returns all the values returned by coroutine.resume, except the first one (the boolean error code). Unlike coroutine.resume, -coroutine.wrap does not catch errors; -any error is propagated to the caller. +the function created by coroutine.wrap +propagates any error to the caller. +In this case, +the function also closes the coroutine (see coroutine.close).

    @@ -1022,6 +1184,8 @@ and lua_yield.

    3 – The Language

    + +

    This section describes the lexis, the syntax, and the semantics of Lua. In other words, @@ -1044,20 +1208,25 @@ at the end of this manual. + +

    3.1 – Lexical Conventions

    Lua is a free-form language. -It ignores spaces (including new lines) and comments -between lexical elements (tokens), -except as delimiters between names and keywords. +It ignores spaces and comments between lexical elements (tokens), +except as delimiters between two tokens. +In source code, +Lua recognizes as spaces the standard ASCII whitespace +characters space, form feed, newline, +carriage return, horizontal tab, and vertical tab.

    Names (also called identifiers) -in Lua can be any string of letters, -digits, and underscores, +in Lua can be any string of Latin letters, +Arabic-Indic digits, and underscores, not beginning with a digit and not being a reserved word. Identifiers are used to name variables, table fields, and labels. @@ -1113,7 +1282,7 @@ and '\'' (apostrophe [single quote]). A backslash followed by a line break results in a newline in the string. The escape sequence '\z' skips the following span -of white-space characters, +of whitespace characters, including line breaks; it is particularly useful to break and indent a long literal string into multiple lines without adding the newlines and spaces @@ -1123,8 +1292,9 @@ nor escapes not forming a valid escape sequence.

    -We can specify any byte in a short literal string by its numeric value -(including embedded zeros). +We can specify any byte in a short literal string, +including embedded zeros, +by its numeric value. This can be done with the escape sequence \xXX, where XX is a sequence of exactly two hexadecimal digits, @@ -1138,9 +1308,12 @@ it must be expressed using exactly three digits.) The UTF-8 encoding of a Unicode character can be inserted in a literal string with the escape sequence \u{XXX} -(note the mandatory enclosing brackets), +(with mandatory enclosing braces), where XXX is a sequence of one or more hexadecimal digits representing the character code point. +This code point can be any value less than 231. +(Lua uses the original UTF-8 specification here, +which is not restricted to valid Unicode code points.)

    @@ -1165,12 +1338,11 @@ Any kind of end-of-line sequence (carriage return, newline, carriage return followed by newline, or newline followed by carriage return) is converted to a simple newline. +When the opening long bracket is immediately followed by a newline, +the newline is not included in the string.

    -For convenience, -when the opening long bracket is immediately followed by a newline, -the newline is not included in the string. As an example, in a system using ASCII (in which 'a' is coded as 97, newline is coded as 10, and '1' is coded as 49), @@ -1191,10 +1363,10 @@ the five literal strings below denote the same string: Any byte in a literal string not explicitly affected by the previous rules represents itself. However, Lua opens files for parsing in text mode, -and the system file functions may have problems with +and the system's file functions may have problems with some control characters. So, it is safer to represent -non-text data as a quoted literal with +binary data as a quoted literal with explicit escape sequences for the non-text characters. @@ -1208,11 +1380,23 @@ which start with 0x or 0X. Hexadecimal constants also accept an optional fractional part plus an optional binary exponent, marked by a letter 'p' or 'P'. + + +

    A numeric constant with a radix point or an exponent denotes a float; otherwise, -if its value fits in an integer, -it denotes an integer. +if its value fits in an integer or it is a hexadecimal constant, +it denotes an integer; +otherwise (that is, a decimal integer numeral that overflows), +it denotes a float. +Hexadecimal numerals with neither a radix point nor an exponent +always denote an integer value; +if the value overflows, it wraps around +to fit into a valid integer. + + +

    Examples of valid integer constants are

    @@ -1233,7 +1417,6 @@ the comment is a short comment,
     which runs until the end of the line.
     Otherwise, it is a long comment,
     which runs until the corresponding closing long bracket.
    -Long comments are frequently used to disable code temporarily.
     
     
     
    @@ -1255,7 +1438,7 @@ which is a particular kind of local variable):
     
     	var ::= Name
     

    -Name denotes identifiers, as defined in §3.1. +Name denotes identifiers (see §3.1).

    @@ -1276,13 +1459,8 @@ Square brackets are used to index a table:

     	var ::= prefixexp ‘[’ exp ‘]

    -The meaning of accesses to table fields can be changed via metatables. -An access to an indexed variable t[i] is equivalent to -a call gettable_event(t,i). -(See §2.4 for a complete description of the -gettable_event function. -This function is not defined or callable in Lua. -We use it here only for explanatory purposes.) +The meaning of accesses to table fields can be changed via metatables +(see §2.4).

    @@ -1297,7 +1475,7 @@ The syntax var.Name is just syntactic sugar for An access to a global variable x is equivalent to _ENV.x. Due to the way that chunks are compiled, -_ENV is never a global name (see §2.2). +the variable _ENV itself is never global (see §2.2). @@ -1305,15 +1483,19 @@ Due to the way that chunks are compiled,

    3.3 – Statements

    + +

    Lua supports an almost conventional set of statements, -similar to those in Pascal or C. +similar to those in other conventional languages. This set includes -assignments, control structures, function calls, +blocks, assignments, control structures, function calls, and variable declarations. + +

    3.3.1 – Blocks

    @@ -1333,7 +1515,7 @@ or write two semicolons in sequence:

    -Function calls and assignments +Both function calls and assignments can start with an open parenthesis. This possibility leads to an ambiguity in Lua's grammar. Consider the following fragment: @@ -1342,7 +1524,7 @@ Consider the following fragment: a = b + c (print or io.write)('done')

    -The grammar could see it in two ways: +The grammar could see this fragment in two ways:

          a = b + c(print or io.write)('done')
    @@ -1396,7 +1578,7 @@ As such, chunks can define local variables,
     receive arguments, and return values.
     Moreover, such anonymous function is compiled as in the
     scope of an external local variable called _ENV (see §2.2).
    -The resulting function always has _ENV as its only upvalue,
    +The resulting function always has _ENV as its only external variable,
     even if it does not use that variable.
     
     
    @@ -1411,7 +1593,7 @@ with an interpreter for the virtual machine.
     
     

    Chunks can also be precompiled into binary form; -see program luac and function string.dump for details. +see the program luac and the function string.dump for details. Programs in source and compiled forms are interchangeable; Lua automatically detects the file type and acts accordingly (see load). @@ -1443,7 +1625,7 @@ the list of variables. If there are more values than needed, the excess values are thrown away. If there are fewer values than needed, -the list is extended with as many nil's as needed. +the list is extended with nil's. If the list of expressions ends with a function call, then all values returned by that call enter the list of values, before the adjustment @@ -1451,8 +1633,10 @@ before the adjustment

    -The assignment statement first evaluates all its expressions -and only then the assignments are performed. +If a variable is both assigned and read +inside a multiple assignment, +Lua ensures all reads get the value of the variable +before the assignment. Thus the code

    @@ -1477,14 +1661,11 @@ cyclically permutes the values of x, y, and z
    -The meaning of assignments to global variables
    -and table fields can be changed via metatables.
    -An assignment to an indexed variable t[i] = val is equivalent to
    -settable_event(t,i,val).
    -(See §2.4 for a complete description of the
    -settable_event function.
    -This function is not defined or callable in Lua.
    -We use it here only for explanatory purposes.)
    +Note that this guarantee covers only accesses
    +syntactically inside the assignment statement.
    +If a function or a metamethod called during the assignment
    +changes the value of a variable,
    +Lua gives no guarantees about the order of that access.
     
     
     

    @@ -1493,6 +1674,12 @@ is equivalent to the assignment _ENV.x = val (see §2.2). +

    +The meaning of assignments to table fields and +global variables (which are actually table fields, too) +can be changed via metatables (see §2.4). + + @@ -1515,9 +1702,9 @@ Lua also has a for statement, in two flavors (see §

    The condition expression of a control structure can return any value. -Both false and nil are considered false. -All values different from nil and false are considered true -(in particular, the number 0 and the empty string are also true). +Both false and nil test false. +All values different from nil and false test true. +In particular, the number 0 and the empty string also test true.

    @@ -1543,11 +1730,12 @@ labels in Lua are considered statements too:

    A label is visible in the entire block where it is defined, -except -inside nested blocks where a label with the same name is defined and -inside nested functions. +except inside nested functions. A goto may jump to any visible label as long as it does not enter into the scope of a local variable. +A label should not be declared +where a label with the same name is visible, +even if this other label has been declared in an enclosing block.

    @@ -1570,7 +1758,7 @@ A break ends the innermost enclosing loop.

    The return statement is used to return values from a function or a chunk -(which is an anonymous function). +(which is handled as an anonymous function). Functions can return more than one value, so the syntax for the return statement is @@ -1582,7 +1770,7 @@ so the syntax for the return statement is

    The return statement can only be written as the last statement of a block. -If it is really necessary to return in the middle of a block, +If it is necessary to return in the middle of a block, then an explicit inner block can be used, as in the idiom do return end, because now return is the last statement in its (inner) block. @@ -1599,72 +1787,70 @@ The for statement has two forms: one numerical and one generic. + +

    The numerical for loop

    +

    The numerical for loop repeats a block of code while a -control variable runs through an arithmetic progression. +control variable goes through an arithmetic progression. It has the following syntax:

     	stat ::= for Name ‘=’ exp ‘,’ exp [‘,’ exp] do block end
     

    -The block is repeated for name starting at the value of -the first exp, until it passes the second exp by steps of the -third exp. -More precisely, a for statement like +The given identifier (Name) defines the control variable, +which is a new variable local to the loop body (block). -

    -     for v = e1, e2, e3 do block end
    -

    -is equivalent to the code: -

    -     do
    -       local var, limit, step = tonumber(e1), tonumber(e2), tonumber(e3)
    -       if not (var and limit and step) then error() end
    -       var = var - step
    -       while true do
    -         var = var + step
    -         if (step >= 0 and var > limit) or (step < 0 and var < limit) then
    -           break
    -         end
    -         local v = var
    -         block
    -       end
    -     end
    -
    +

    +The loop starts by evaluating once the three control expressions. +Their values are called respectively +the initial value, the limit, and the step. +If the step is absent, it defaults to 1. +

    -Note the following: +If both the initial value and the step are integers, +the loop is done with integers; +note that the limit may not be an integer. +Otherwise, the three values are converted to +floats and the loop is done with floats. +Beware of floating-point accuracy in this case. -

      -
    • -All three control expressions are evaluated only once, -before the loop starts. -They must all result in numbers. -
    • +

      +After that initialization, +the loop body is repeated with the value of the control variable +going through an arithmetic progression, +starting at the initial value, +with a common difference given by the step. +A negative step makes a decreasing sequence; +a step equal to zero raises an error. +The loop continues while the value is less than +or equal to the limit +(greater than or equal to for a negative step). +If the initial value is already greater than the limit +(or less than, if the step is negative), +the body is not executed. -

    • -var, limit, and step are invisible variables. -The names shown here are for explanatory purposes only. -
    • -
    • -If the third expression (the step) is absent, -then a step of 1 is used. -
    • +

      +For integer loops, +the control variable never wraps around; +instead, the loop ends in case of an overflow. -

    • -You can use break and goto to exit a for loop. -
    • -
    • -The loop variable v is local to the loop body. +

      +You should not change the value of the control variable +during the loop. If you need its value after the loop, assign it to another variable before exiting the loop. -

    • -
    + + + + +

    The generic for loop

    The generic for statement works over functions, @@ -1680,49 +1866,50 @@ The generic for loop has the following syntax: A for statement like

    -     for var_1, ···, var_n in explist do block end
    +     for var_1, ···, var_n in explist do body end
     

    -is equivalent to the code: +works as follows. -

    -     do
    -       local f, s, var = explist
    -       while true do
    -         local var_1, ···, var_n = f(s, var)
    -         if var_1 == nil then break end
    -         var = var_1
    -         block
    -       end
    -     end
    -

    -Note the following: -

    @@ -1743,16 +1930,32 @@ Function calls are explained in §3.4.10.

    3.3.7 – Local Declarations

    Local variables can be declared anywhere inside a block. -The declaration can include an initial assignment: +The declaration can include an initialization:

    -	stat ::= local namelist [‘=’ explist]
    +	stat ::= local attnamelist [‘=’ explist]
    +	attnamelist ::=  Name attrib {‘,’ Name attrib}
     

    If present, an initial assignment has the same semantics of a multiple assignment (see §3.3.3). Otherwise, all variables are initialized with nil. +

    +Each variable name may be postfixed by an attribute +(a name between angle brackets): + +

    +	attrib ::= [‘<’ Name ‘>’]
    +

    +There are two possible attributes: +const, which declares a constant variable, +that is, a variable that cannot be assigned to +after its initialization; +and close, which declares a to-be-closed variable (see §3.3.8). +A list of variables can contain at most one to-be-closed variable. + +

    A chunk is also a block (see §3.3.2), and so local variables can be declared in a chunk outside any explicit block. @@ -1765,10 +1968,73 @@ The visibility rules for local variables are explained in §3 +

    3.3.8 – To-be-closed Variables

    + +

    +A to-be-closed variable behaves like a constant local variable, +except that its value is closed whenever the variable +goes out of scope, including normal block termination, +exiting its block by break/goto/return, +or exiting by an error. + + +

    +Here, to close a value means +to call its __close metamethod. +When calling the metamethod, +the value itself is passed as the first argument +and the error object that caused the exit (if any) +is passed as a second argument; +if there was no error, the second argument is nil. + + +

    +The value assigned to a to-be-closed variable +must have a __close metamethod +or be a false value. +(nil and false are ignored as to-be-closed values.) + + +

    +If several to-be-closed variables go out of scope at the same event, +they are closed in the reverse order that they were declared. + + +

    +If there is any error while running a closing method, +that error is handled like an error in the regular code +where the variable was defined. +After an error, +the other pending closing methods will still be called. + + +

    +If a coroutine yields and is never resumed again, +some variables may never go out of scope, +and therefore they will never be closed. +(These variables are the ones created inside the coroutine +and in scope at the point where the coroutine yielded.) +Similarly, if a coroutine ends with an error, +it does not unwind its stack, +so it does not close any variable. +In both cases, +you can either use finalizers +or call coroutine.close to close the variables. +However, if the coroutine was created +through coroutine.wrap, +then its corresponding function will close the coroutine +in case of errors. + + + + +

    3.4 – Expressions

    + +

    The basic expressions in Lua are the following: @@ -1831,17 +2097,17 @@ Here are some examples: g(f(), x) -- f() is adjusted to 1 result g(x, f()) -- g gets x plus all results from f() a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil) - a,b = ... -- a gets the first vararg parameter, b gets + a,b = ... -- a gets the first vararg argument, b gets -- the second (both a and b can get nil if there - -- is no corresponding vararg parameter) + -- is no corresponding vararg argument) a,b,c = x, f() -- f() is adjusted to 2 results a,b,c = f() -- f() is adjusted to 3 results return f() -- returns all results from f() - return ... -- returns all received vararg parameters + return ... -- returns all received vararg arguments return x,y,f() -- returns x, y, and all results from f() {f()} -- creates a list with all results from f() - {...} -- creates a list with all vararg parameters + {...} -- creates a list with all vararg arguments {f(), nil} -- f() is adjusted to 1 result

    @@ -1855,6 +2121,8 @@ or nil if f does not return any values.) + +

    3.4.1 – Arithmetic Operators

    Lua supports the following arithmetic operators: @@ -1874,14 +2142,14 @@ With the exception of exponentiation and float division, the arithmetic operators work as follows: If both operands are integers, the operation is performed over integers and the result is an integer. -Otherwise, if both operands are numbers -or strings that can be converted to -numbers (see §3.4.3), +Otherwise, if both operands are numbers, then they are converted to floats, -the operation is performed following the usual rules +the operation is performed following the machine's rules for floating-point arithmetic (usually the IEEE 754 standard), and the result is a float. +(The string library coerces strings to numbers in +arithmetic operations; see §3.4.3 for details.)

    @@ -1895,7 +2163,7 @@ so that it works for non-integer exponents too.

    Floor division (//) is a division that rounds the quotient towards minus infinity, -that is, the floor of the division of its operands. +resulting in the floor of the division of its operands.

    @@ -1905,11 +2173,7 @@ that rounds the quotient towards minus infinity (floor division).

    In case of overflows in integer arithmetic, -all operations wrap around, -according to the usual rules of two-complement arithmetic. -(In other words, -they return the unique representable integer -that is equal modulo 264 to the mathematical result.) +all operations wrap around. @@ -1950,19 +2214,13 @@ Bitwise operators always convert float operands to integers. Exponentiation and float division always convert integer operands to floats. All other arithmetic operations applied to mixed numbers -(integers and floats) convert the integer operand to a float; -this is called the usual rule. +(integers and floats) convert the integer operand to a float. The C API also converts both integers to floats and floats to integers, as needed. Moreover, string concatenation accepts numbers as arguments, besides strings. -

    -Lua also converts strings to numbers, -whenever a number is expected. - -

    In a conversion from integer to float, if the integer value has an exact representation as a float, @@ -1983,28 +2241,45 @@ Otherwise, the conversion fails.

    -The conversion from strings to numbers goes as follows: -First, the string is converted to an integer or a float, -following its syntax and the rules of the Lua lexer. -(The string may have also leading and trailing spaces and a sign.) -Then, the resulting number (float or integer) -is converted to the type (float or integer) required by the context -(e.g., the operation that forced the conversion). +Several places in Lua coerce strings to numbers when necessary. +In particular, +the string library sets metamethods that try to coerce +strings to numbers in all arithmetic operations. +If the conversion fails, +the library calls the metamethod of the other operand +(if present) or it raises an error. +Note that bitwise operators do not do this coercion. + + +

    +Nonetheless, it is always a good practice not to rely on these +implicit coercions, as they are not always applied; +in particular, "1"==1 is false and "1"<1 raises an error +(see §3.4.4). +These coercions exist mainly for compatibility and may be removed +in future versions of the language.

    +A string is converted to an integer or a float +following its syntax and the rules of the Lua lexer. +The string may have also leading and trailing whitespaces and a sign. All conversions from strings to numbers accept both a dot and the current locale mark as the radix character. (The Lua lexer, however, accepts only a dot.) +If the string is not a valid numeral, +the conversion fails. +If necessary, the result of this first step is then converted +to a specific number subtype following the previous rules +for conversions between floats and integers.

    The conversion from numbers to strings uses a non-specified human-readable format. -For complete control over how numbers are converted to strings, -use the format function from the string library -(see string.format). +To convert numbers to strings in any specific way, +use the function string.format. @@ -2028,7 +2303,7 @@ These operators always result in false or true. Equality (==) first compares the type of its operands. If the types are different, then the result is false. Otherwise, the values of the operands are compared. -Strings are compared in the obvious way. +Strings are equal if they have the same byte content. Numbers are equal if they denote the same mathematical value. @@ -2037,16 +2312,19 @@ Tables, userdata, and threads are compared by reference: two objects are considered equal only if they are the same object. Every time you create a new object -(a table, userdata, or thread), +(a table, a userdata, or a thread), this new object is different from any previously existing object. -Closures with the same reference are always equal. -Closures with any detectable difference +A function is always equal to itself. +Functions with any detectable difference (different behavior, different definition) are always different. +Functions created at different times but with no detectable differences +may be classified as equal or not +(depending on internal caching details).

    You can change the way that Lua compares tables and userdata -by using the "eq" metamethod (see §2.4). +by using the __eq metamethod (see §2.4).

    @@ -2064,11 +2342,11 @@ The operator ~= is exactly the negation of equality (== The order operators work as follows. If both arguments are numbers, -then they are compared according to their mathematical values -(regardless of their subtypes). +then they are compared according to their mathematical values, +regardless of their subtypes. Otherwise, if both arguments are strings, then their values are compared according to the current locale. -Otherwise, Lua tries to call the "lt" or the "le" +Otherwise, Lua tries to call the __lt or the __le metamethod (see §2.4). A comparison a > b is translated to b < a and a >= b is translated to b <= a. @@ -2076,8 +2354,8 @@ and a >= b is translated to b <= a.

    Following the IEEE 754 standard, -NaN is considered neither smaller than, -nor equal to, nor greater than any value (including itself). +the special value NaN is considered neither less than, +nor equal to, nor greater than any value, including itself. @@ -2113,10 +2391,7 @@ Here are some examples: false and nil --> false false or nil --> nil 10 and 20 --> 20 -

    -(In this manual, ---> indicates the result of the preceding expression.) - + @@ -2124,8 +2399,9 @@ Here are some examples:

    3.4.6 – Concatenation

    The string concatenation operator in Lua is denoted by two dots ('..'). -If both operands are strings or numbers, then they are converted to -strings according to the rules described in §3.4.3. +If both operands are strings or numbers, +then the numbers are converted to strings +in a non-specified format (see §3.4.3). Otherwise, the __concat metamethod is called (see §2.4). @@ -2139,24 +2415,29 @@ The length operator is denoted by the unary prefix operator #.

    -The length of a string is its number of bytes -(that is, the usual meaning of string length when each -character is one byte). +The length of a string is its number of bytes. +(That is the usual meaning of string length when each +character is one byte.)

    The length operator applied on a table returns a border in that table. -A border in a table t is any natural number +A border in a table t is any non-negative integer that satisfies the following condition:

    -     (border == 0 or t[border] ~= nil) and t[border + 1] == nil
    +     (border == 0 or t[border] ~= nil) and
    +     (t[border + 1] == nil or border == math.maxinteger)
     

    In words, -a border is any (natural) index in a table -where a non-nil value is followed by a nil value -(or zero, when index 1 is nil). +a border is any positive integer index present in the table +that is followed by an absent index, +plus two limit cases: +zero, when index 1 is absent; +and the maximum value for an integer, when that index is present. +Note that keys that are not positive integers +do not interfere with borders.

    @@ -2165,12 +2446,11 @@ For instance, the table {10, 20, 30, 40, 50} is a sequence, as it has only one border (5). The table {10, 20, 30, nil, 50} has two borders (3 and 5), and therefore it is not a sequence. +(The nil at index 4 is called a hole.) The table {nil, 20, 30, nil, nil, 60, nil} has three borders (0, 3, and 6), so it is not a sequence, too. The table {} is a sequence with border 0. -Note that non-natural keys do not interfere -with whether a table is a sequence.

    @@ -2188,7 +2468,7 @@ the memory addresses of its non-numeric keys.)

    The computation of the length of a table has a guaranteed worst time of O(log n), -where n is the largest natural key in the table. +where n is the largest integer key in the table.

    @@ -2246,10 +2526,10 @@ Each field of the form [exp1] = exp2 adds to the new table an entry with key exp1 and value exp2. A field of the form name = exp is equivalent to ["name"] = exp. -Finally, fields of the form exp are equivalent to +Fields of the form exp are equivalent to [i] = exp, where i are consecutive integers -starting with 1. -Fields in the other formats do not affect this counting. +starting with 1; +fields in the other formats do not affect this counting. For example,

    @@ -2302,8 +2582,9 @@ first prefixexp and args are evaluated.
     If the value of prefixexp has type function,
     then this function is called
     with the given arguments.
    -Otherwise, the prefixexp "call" metamethod is called,
    -having as first parameter the value of prefixexp,
    +Otherwise, if present,
    +the prefixexp __call metamethod is called:
    +its first argument is the value of prefixexp,
     followed by the original call arguments
     (see §2.4).
     
    @@ -2314,7 +2595,7 @@ The form
     
     	functioncall ::= prefixexp ‘:’ Name args
     

    -can be used to call "methods". +can be used to emulate methods. A call v:name(args) is syntactic sugar for v.name(v,args), except that v is evaluated only once. @@ -2339,8 +2620,8 @@ that is, the argument list is a single literal string.

    -A call of the form return functioncall is called -a tail call. +A call of the form return functioncall not in the +scope of a to-be-closed variable is called a tail call. Lua implements proper tail calls (or proper tail recursion): in a tail call, @@ -2350,14 +2631,16 @@ a program can execute. However, a tail call erases any debug information about the calling function. Note that a tail call only happens with a particular syntax, -where the return has one single function call as argument; -this syntax makes the calling function return exactly -the returns of the called function. +where the return has one single function call as argument, +and it is outside the scope of any to-be-closed variable. +This syntax makes the calling function return exactly +the returns of the called function, +without any intervening action. So, none of the following examples are tail calls:

          return (f(x))        -- results adjusted to 1
    -     return 2 * f(x)
    +     return 2 * f(x)      -- result multiplied by 2
          return x, f(x)       -- additional results
          f(x); return         -- results discarded
          return x or f(x)     -- results adjusted to 1
    @@ -2427,10 +2710,11 @@ contains references to f.)
     A function definition is an executable expression,
     whose value has type function.
     When Lua precompiles a chunk,
    -all its function bodies are precompiled too.
    +all its function bodies are precompiled too,
    +but they are not created yet.
     Then, whenever Lua executes the function definition,
     the function is instantiated (or closed).
    -This function instance (or closure)
    +This function instance, or closure,
     is the final value of the expression.
     
     
    @@ -2441,9 +2725,9 @@ initialized with the argument values:
     
     	parlist ::= namelist [‘,’ ‘...’] | ‘...

    -When a function is called, -the list of arguments is adjusted to -the length of the list of parameters, +When a Lua function is called, +it adjusts its list of arguments to +the length of its list of parameters, unless the function is a vararg function, which is indicated by three dots ('...') at the end of its parameter list. @@ -2473,7 +2757,7 @@ Then, we have the following mapping from arguments to parameters and to the vararg expression:

    -     CALL            PARAMETERS
    +     CALL             PARAMETERS
          
          f(3)             a=3, b=nil
          f(3, 4)          a=3, b=4
    @@ -2498,13 +2782,13 @@ then the function returns with no results.
     
     There is a system-dependent limit on the number of values
     that a function may return.
    -This limit is guaranteed to be larger than 1000.
    +This limit is guaranteed to be greater than 1000.
     
     
     

    The colon syntax -is used for defining methods, -that is, functions that have an implicit extra parameter self. +is used to emulate methods, +adding an implicit extra parameter self to the function. Thus, the statement

    @@ -2556,8 +2840,8 @@ and so the second x refers to the outside variable.
     Because of the lexical scoping rules,
     local variables can be freely accessed by functions
     defined inside their scope.
    -A local variable used by an inner function is called
    -an upvalue, or external local variable,
    +A local variable used by an inner function is called an upvalue
    +(or external local variable, or simply external variable)
     inside the inner function.
     
     
    @@ -2569,9 +2853,9 @@ Consider the following example:
     
          a = {}
          local x = 20
    -     for i=1,10 do
    +     for i = 1, 10 do
            local y = 0
    -       a[i] = function () y=y+1; return x+y end
    +       a[i] = function () y = y + 1; return x + y end
          end
     

    The loop creates ten closures @@ -2585,6 +2869,8 @@ while all of them share the same x.

    4 – The Application Program Interface

    + +

    This section describes the C API for Lua, that is, @@ -2605,7 +2891,8 @@ and so do not generate any hidden side-effects.

    As in most C libraries, -the Lua API functions do not check their arguments for validity or consistency. +the Lua API functions do not check their arguments +for validity or consistency. However, you can change this behavior by compiling Lua with the macro LUA_USE_APICHECK defined. @@ -2633,8 +2920,12 @@ to the main thread in the new state. + +

    4.1 – The Stack

    + +

    Lua uses a virtual stack to pass values to and from C. Each element in this stack represents a Lua value @@ -2658,8 +2949,8 @@ For convenience, most query operations in the API do not follow a strict stack discipline. Instead, they can refer to any element in the stack by using an index: -A positive index represents an absolute stack position -(starting at 1); +A positive index represents an absolute stack position, +starting at 1 as the bottom of the stack; a negative index represents an offset relative to the top of the stack. More specifically, if the stack has n elements, then index 1 represents the first element @@ -2674,39 +2965,44 @@ and index -n represents the first element. -

    4.2 – Stack Size

    +

    4.1.1 – Stack Size

    When you interact with the Lua API, you are responsible for ensuring consistency. In particular, you are responsible for controlling stack overflow. -You can use the function lua_checkstack -to ensure that the stack has enough space for pushing new elements. +When you call any API function, +you must ensure the stack has enough room to accommodate the results. + + +

    +There is one exception to the above rule: +When you call a Lua function +without a fixed number of results (see lua_call), +Lua ensures that the stack has enough space for all results. +However, it does not ensure any extra space. +So, before pushing anything on the stack after such a call +you should use lua_checkstack.

    Whenever Lua calls C, it ensures that the stack has space for -at least LUA_MINSTACK extra slots. +at least LUA_MINSTACK extra elements; +that is, you can safely push up to LUA_MINSTACK values into it. LUA_MINSTACK is defined as 20, so that usually you do not have to worry about stack space unless your code has loops pushing elements onto the stack. - - -

    -When you call a Lua function -without a fixed number of results (see lua_call), -Lua ensures that the stack has enough space for all results, -but it does not ensure any extra space. -So, before pushing anything in the stack after such a call -you should use lua_checkstack. +Whenever necessary, +you can use the function lua_checkstack +to ensure that the stack has enough space for pushing new elements. -

    4.3 – Valid and Acceptable Indices

    +

    4.1.2 – Valid and Acceptable Indices

    Any function in the API that receives stack indices @@ -2722,8 +3018,8 @@ It comprises stack indices between 1 and the stack top plus pseudo-indices, which represent some positions that are accessible to C code but that are not in the stack. -Pseudo-indices are used to access the registry (see §4.5) -and the upvalues of a C function (see §4.4). +Pseudo-indices are used to access the registry (see §4.3) +and the upvalues of a C function (see §4.2).

    @@ -2735,6 +3031,8 @@ but it also can be any positive index after the stack top within the space allocated for the stack, that is, indices up to the stack size. (Note that 0 is never an acceptable index.) +Indices to upvalues (see §4.2) greater than the real number +of upvalues in the current C function are also acceptable (but invalid). Except when noted otherwise, functions in the API work with acceptable indices. @@ -2743,7 +3041,7 @@ functions in the API work with acceptable indices. Acceptable indices serve to avoid extra tests against the stack top when querying the stack. For instance, a C function can query its third argument -without the need to first check whether there is a third argument, +without the need to check whether there is a third argument, that is, without the need to check whether 3 is a valid index. @@ -2757,7 +3055,52 @@ which behaves like a nil value. -

    4.4 – C Closures

    +

    4.1.3 – Pointers to strings

    + +

    +Several functions in the API return pointers (const char*) +to Lua strings in the stack. +(See lua_pushfstring, lua_pushlstring, +lua_pushstring, and lua_tolstring. +See also luaL_checklstring, luaL_checkstring, +and luaL_tolstring in the auxiliary library.) + + +

    +In general, +Lua's garbage collection can free or move internal memory +and then invalidate pointers to internal strings. +To allow a safe use of these pointers, +The API guarantees that any pointer to a string in a stack index +is valid while the string value at that index is not removed from the stack. +(It can be moved to another index, though.) +When the index is a pseudo-index (referring to an upvalue), +the pointer is valid while the corresponding call is active and +the corresponding upvalue is not modified. + + +

    +Some functions in the debug interface +also return pointers to strings, +namely lua_getlocal, lua_getupvalue, +lua_setlocal, and lua_setupvalue. +For these functions, the pointer is guaranteed to +be valid while the caller function is active and +the given closure (if one was given) is in the stack. + + +

    +Except for these guarantees, +the garbage collector is free to invalidate +any pointer to internal strings. + + + + + + + +

    4.2 – C Closures

    When a C function is created, @@ -2783,16 +3126,21 @@ which is one plus the maximum number of upvalues in a closure), produces an acceptable but invalid index. +

    +A C closure can also change the values +of its corresponding upvalues. + + -

    4.5 – Registry

    +

    4.3 – Registry

    Lua provides a registry, a predefined table that can be used by any C code to store whatever Lua values it needs to store. -The registry table is always located at pseudo-index +The registry table is always accessible at pseudo-index LUA_REGISTRYINDEX. Any C library can store data into this table, but it must take care to choose keys @@ -2810,7 +3158,8 @@ uppercase letters are reserved for Lua. The integer keys in the registry are used by the reference mechanism (see luaL_ref) and by some predefined values. -Therefore, integer keys must not be used for other purposes. +Therefore, integer keys in the registry +must not be used for other purposes.

    @@ -2834,14 +3183,16 @@ the global environment. -

    4.6 – Error Handling in C

    +

    4.4 – Error Handling in C

    + +

    Internally, Lua uses the C longjmp facility to handle errors. (Lua will use exceptions if you compile it as C++; search for LUAI_THROW in the source code for details.) -When Lua faces any error -(such as a memory allocation error or a type error) +When Lua faces any error, +such as a memory allocation error or a type error, it raises an error; that is, it does a long jump. A protected environment uses setjmp @@ -2850,7 +3201,8 @@ any error jumps to the most recent active recovery point.

    -Inside a C function you can raise an error by calling lua_error. +Inside a C function you can raise an error explicitly +by calling lua_error.

    @@ -2881,7 +3233,7 @@ it can do whatever it wants on that Lua state, as it should be already protected. However, when C code operates on other Lua states -(e.g., a Lua parameter to the function, +(e.g., a Lua-state argument to the function, a Lua state stored in the registry, or the result of lua_newthread), it should use them only in API calls that cannot raise errors. @@ -2889,16 +3241,51 @@ it should use them only in API calls that cannot raise errors.

    The panic function runs as if it were a message handler (see §2.3); -in particular, the error object is at the top of the stack. +in particular, the error object is on the top of the stack. However, there is no guarantee about stack space. To push anything on the stack, -the panic function must first check the available space (see §4.2). +the panic function must first check the available space (see §4.1.1). -

    4.7 – Handling Yields in C

    +

    4.4.1 – Status Codes

    + +

    +Several functions that report errors in the API use the following +status codes to indicate different kinds of errors or other conditions: + +

      + +
    • LUA_OK (0): no errors.
    • + +
    • LUA_ERRRUN: a runtime error.
    • + +
    • LUA_ERRMEM: +memory allocation error. +For such errors, Lua does not call the message handler. +
    • + +
    • LUA_ERRERR: error while running the message handler.
    • + +
    • LUA_ERRSYNTAX: syntax error during precompilation.
    • + +
    • LUA_YIELD: the thread (coroutine) yields.
    • + +
    • LUA_ERRFILE: a file-related error; +e.g., it cannot open or read the file.
    • + +

    +These constants are defined in the header file lua.h. + + + + + + + +

    4.5 – Handling Yields in C

    Internally, Lua uses the C longjmp facility to yield a coroutine. @@ -2906,7 +3293,7 @@ Therefore, if a C function foo calls an API function and this API function yields (directly or indirectly by calling another function that yields), Lua cannot return to foo any more, -because the longjmp removes its frame from the C stack. +because the longjmp removes its frame from the C stack.

    @@ -2925,9 +3312,9 @@ the original function. This original function then calls one of those three functions in the C API, which we will call the callee function, that then yields the current thread. -(This can happen when the callee function is lua_yieldk, +This can happen when the callee function is lua_yieldk, or when the callee function is either lua_callk or lua_pcallk -and the function called by them yields.) +and the function called by them yields.

    @@ -2936,7 +3323,7 @@ After the thread resumes, it eventually will finish running the callee function. However, the callee function cannot return to the original function, -because its frame in the C stack was destroyed by the yield. +because its frame in the C stack was destroyed by the yield. Instead, Lua calls a continuation function, which was given as an argument to the callee function. As the name implies, @@ -2997,11 +3384,11 @@ you can do the equivalent work directly inside the original function.)

    Besides the Lua state, the continuation function has two other parameters: -the final status of the call plus the context value (ctx) that +the final status of the call and the context value (ctx) that was passed originally to lua_pcallk. -(Lua does not use this context value; +Lua does not use this context value; it only passes this value from the original function to the -continuation function.) +continuation function. For lua_pcallk, the status is the same value that would be returned by lua_pcallk, except that it is LUA_YIELD when being executed after a yield @@ -3035,7 +3422,7 @@ of the original function. -

    4.8 – Functions and Types

    +

    4.6 – Functions and Types

    Here we list all functions and types from the C API in @@ -3055,17 +3442,16 @@ A field in the form x|y means the function can push (or pop) depending on the situation; an interrogation mark '?' means that we cannot know how many elements the function pops/pushes -by looking only at its arguments -(e.g., they may depend on what is on the stack). +by looking only at its arguments. +(For instance, they may depend on what is in the stack.) The third field, x, tells whether the function may raise errors: '-' means the function never raises any error; -'m' means the function may raise out-of-memory errors -and errors running a __gc metamethod; -'e' means the function may raise any errors -(it can run arbitrary Lua code, -either directly or through metamethods); -'v' means the function may raise an error on purpose. +'m' means the function may raise only out-of-memory errors; +'v' means the function may raise the errors explained in the text; +'e' means the function can run arbitrary Lua code, +either directly or through metamethods, +and therefore may raise any errors. @@ -3076,7 +3462,7 @@ either directly or through metamethods);

    Converts the acceptable index idx into an equivalent absolute index -(that is, one that does not depend on the stack top). +(that is, one that does not depend on the stack size). @@ -3125,16 +3511,14 @@ Lua assumes the following behavior from the allocator function:

    When nsize is zero, the allocator must behave like free -and return NULL. +and then return NULL.

    When nsize is not zero, the allocator must behave like realloc. -The allocator returns NULL +In particular, the allocator returns NULL if and only if it cannot fulfill the request. -Lua assumes that the allocator never fails when -osize >= nsize.

    @@ -3156,9 +3540,6 @@ It is used in the auxiliary library by luaL_newst Note that Standard C ensures that free(NULL) has no effect and that realloc(NULL,size) is equivalent to malloc(size). -This code assumes that realloc does not fail when shrinking a block. -(Although Standard C does not ensure this behavior, -it seems to be a safe assumption.) @@ -3172,7 +3553,7 @@ it seems to be a safe assumption.) Performs an arithmetic or bitwise operation over the two values (or one, in the case of negations) at the top of the stack, -with the value at the top being the second operand, +with the value on the top being the second operand, pops these values, and pushes the result of the operation. The function follows the semantics of the corresponding Lua operator (that is, it may call metamethods). @@ -3208,7 +3589,7 @@ The value of op must be one of the following constants:

    lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf);

    -Sets a new panic function and returns the old one (see §4.6). +Sets a new panic function and returns the old one (see §4.4). @@ -3220,19 +3601,23 @@ Sets a new panic function and returns the old one (see §4.6<

    Calls a function. +Like regular Lua calls, +lua_call respects the __call metamethod. +So, here the word "function" +means any callable value.

    -To call a function you must use the following protocol: +To do a call you must use the following protocol: first, the function to be called is pushed onto the stack; -then, the arguments to the function are pushed +then, the arguments to the call are pushed in direct order; that is, the first argument is pushed first. Finally you call lua_call; nargs is the number of arguments that you pushed onto the stack. -All arguments and the function value are popped from the stack -when the function is called. -The function results are pushed onto the stack when the function returns. +When the function returns, +all arguments and the function value are popped +and the call results are pushed onto the stack. The number of results is adjusted to nresults, unless nresults is LUA_MULTRET. In this case, all results from the function are pushed; @@ -3244,7 +3629,7 @@ so that after the call the last result is on the top of the stack.

    -Any error inside the called function is propagated upwards +Any error while calling and running the function is propagated upwards (with a longjmp). @@ -3285,7 +3670,7 @@ This is considered good programming practice.

    This function behaves exactly like lua_call, -but allows the called function to yield (see §4.7). +but allows the called function to yield (see §4.5). @@ -3310,7 +3695,7 @@ The first argument (if any) is at index 1 and its last argument is at index lua_gettop(L). To return values to Lua, a C function just pushes them onto the stack, in direct order (the first result is pushed first), -and returns the number of results. +and returns in C the number of results. Any other value in the stack below the results will be properly discarded by Lua. Like a Lua function, a C function called by Lua can also return @@ -3347,34 +3732,61 @@ of numeric arguments and returns their average and their sum:

    int lua_checkstack (lua_State *L, int n);

    -Ensures that the stack has space for at least n extra slots -(that is, that you can safely push up to n values into it). +Ensures that the stack has space for at least n extra elements, +that is, that you can safely push up to n values into it. It returns false if it cannot fulfill the request, either because it would cause the stack -to be larger than a fixed maximum size +to be greater than a fixed maximum size (typically at least several thousand elements) or because it cannot allocate memory for the extra space. This function never shrinks the stack; -if the stack already has space for the extra slots, +if the stack already has space for the extra elements, it is left unchanged. -


    lua_close

    -[-0, +0, –] -

    void lua_close (lua_State *L);
    +

    lua_close

    +[-0, +0, –] +

    void lua_close (lua_State *L);
    + +

    +Close all active to-be-closed variables in the main thread, +release all objects in the given Lua state +(calling the corresponding garbage-collection metamethods, if any), +and frees all dynamic memory used by this state. + + +

    +On several platforms, you may not need to call this function, +because all resources are naturally released when the host program ends. +On the other hand, long-running programs that create multiple states, +such as daemons or web servers, +will probably need to close states as soon as they are not needed. + + + + + +


    lua_closeslot

    +[-0, +0, e] +

    void lua_closeslot (lua_State *L, int index);
    + +

    +Close the to-be-closed slot at the given index and set its value to nil. +The index must be the last index previously marked to be closed +(see lua_toclose) that is still active (that is, not closed yet). + + +

    +A __close metamethod cannot yield +when called through this function. +

    -Destroys all objects in the given Lua state -(calling the corresponding garbage-collection metamethods, if any) -and frees all dynamic memory used by this state. -On several platforms, you may not need to call this function, -because all resources are naturally released when the host program ends. -On the other hand, long-running programs that create multiple states, -such as daemons or web servers, -will probably need to close states as soon as they are not needed. +(Exceptionally, this function was introduced in release 5.4.3. +It is not present in previous 5.4 releases.) @@ -3414,7 +3826,7 @@ The value of op must be one of the following constants:

    Concatenates the n values at the top of the stack, -pops them, and leaves the result at the top. +pops them, and leaves the result on the top. If n is 1, the result is the single value on the stack (that is, the function does nothing); if n is 0, the result is the empty string. @@ -3450,7 +3862,7 @@ will have as a sequence; parameter nrec is a hint for how many other elements the table will have. Lua may use these hints to preallocate memory for the new table. -This preallocation is useful for performance when you know in advance +This preallocation may help performance when you know in advance how many elements the table will have. Otherwise you can use the function lua_newtable. @@ -3502,8 +3914,8 @@ This function does not pop the Lua function from the stack.

    int lua_error (lua_State *L);

    -Generates a Lua error, -using the value at the top of the stack as the error object. +Raises a Lua error, +using the value on the top of the stack as the error object. This function does a long jump, and therefore never returns (see luaL_error). @@ -3513,8 +3925,8 @@ and therefore never returns


    lua_gc

    -[-0, +0, m] -

    int lua_gc (lua_State *L, int what, int data);
    +[-0, +0, –] +
    int lua_gc (lua_State *L, int what, ...);

    Controls the garbage collector. @@ -3522,59 +3934,64 @@ Controls the garbage collector.

    This function performs several tasks, -according to the value of the parameter what: +according to the value of the parameter what. +For options that need extra arguments, +they are listed after the option.

      -
    • LUA_GCSTOP: -stops the garbage collector. +
    • LUA_GCCOLLECT: +Performs a full garbage-collection cycle.
    • -
    • LUA_GCRESTART: -restarts the garbage collector. +
    • LUA_GCSTOP: +Stops the garbage collector.
    • -
    • LUA_GCCOLLECT: -performs a full garbage-collection cycle. +
    • LUA_GCRESTART: +Restarts the garbage collector.
    • LUA_GCCOUNT: -returns the current amount of memory (in Kbytes) in use by Lua. +Returns the current amount of memory (in Kbytes) in use by Lua.
    • LUA_GCCOUNTB: -returns the remainder of dividing the current amount of bytes of +Returns the remainder of dividing the current amount of bytes of memory in use by Lua by 1024.
    • -
    • LUA_GCSTEP: -performs an incremental step of garbage collection. +
    • LUA_GCSTEP (int stepsize): +Performs an incremental step of garbage collection, +corresponding to the allocation of stepsize Kbytes.
    • -
    • LUA_GCSETPAUSE: -sets data as the new value -for the pause of the collector (see §2.5) -and returns the previous value of the pause. +
    • LUA_GCISRUNNING: +Returns a boolean that tells whether the collector is running +(i.e., not stopped).
    • -
    • LUA_GCSETSTEPMUL: -sets data as the new value for the step multiplier of -the collector (see §2.5) -and returns the previous value of the step multiplier. +
    • LUA_GCINC (int pause, int stepmul, stepsize): +Changes the collector to incremental mode +with the given parameters (see §2.5.1). +Returns the previous mode (LUA_GCGEN or LUA_GCINC).
    • -
    • LUA_GCISRUNNING: -returns a boolean that tells whether the collector is running -(i.e., not stopped). +
    • LUA_GCGEN (int minormul, int majormul): +Changes the collector to generational mode +with the given parameters (see §2.5.2). +Returns the previous mode (LUA_GCGEN or LUA_GCINC).
    • -
    - -

    +

    For more details about these options, see collectgarbage. +

    +This function should not be called by a finalizer. + + @@ -3685,7 +4102,7 @@ the function returns 0 and pushes nothing on the stack.

    Pushes onto the stack the value t[k], where t is the value at the given index -and k is the value at the top of the stack. +and k is the value on the top of the stack.

    @@ -3716,17 +4133,19 @@ in particular, 0 means an empty stack. -


    lua_getuservalue

    +


    lua_getiuservalue

    [-0, +1, –] -

    int lua_getuservalue (lua_State *L, int index);
    +
    int lua_getiuservalue (lua_State *L, int index, int n);

    -Pushes onto the stack the Lua value associated with the full userdata -at the given index. +Pushes onto the stack the n-th user value associated with the +full userdata at the given index and +returns the type of the pushed value.

    -Returns the type of the pushed value. +If the userdata does not have that value, +pushes nil and returns LUA_TNONE. @@ -3961,7 +4380,7 @@ Otherwise, it is defined as ptrdiff_t.

    typedef int (*lua_KFunction) (lua_State *L, int status, lua_KContext ctx);

    -Type for continuation functions (see §4.7). +Type for continuation functions (see §4.5). @@ -3997,27 +4416,6 @@ function on top of the stack. Otherwise, it pushes an error message. -

    -The return values of lua_load are: - -

      - -
    • LUA_OK: no errors;
    • - -
    • LUA_ERRSYNTAX: -syntax error during precompilation;
    • - -
    • LUA_ERRMEM: -memory allocation (out-of-memory) error;
    • - -
    • LUA_ERRGCMM: -error while running a __gc metamethod. -(This error has no relation with the chunk being loaded. -It is generated by the garbage collector.) -
    • - -
    -

    The lua_load function uses a user-supplied reader function to read the chunk (see lua_Reader). @@ -4026,7 +4424,7 @@ The data argument is an opaque value passed to the reader function.

    The chunkname argument gives a name to the chunk, -which is used for error messages and in debug information (see §4.9). +which is used for error messages and in debug information (see §4.7).

    @@ -4043,10 +4441,17 @@ so the reader function must always leave the stack unmodified when returning. +

    +lua_load can return +LUA_OK, LUA_ERRSYNTAX, or LUA_ERRMEM. +The function may also return other values corresponding to +errors raised by the read function (see §4.4.1). + +

    If the resulting function has upvalues, its first upvalue is set to the value of the global environment -stored at index LUA_RIDX_GLOBALS in the registry (see §4.5). +stored at index LUA_RIDX_GLOBALS in the registry (see §4.3). When loading main chunks, this upvalue will be the _ENV variable (see §2.2). Other upvalues are initialized with nil. @@ -4060,11 +4465,11 @@ Other upvalues are initialized with nil.

    lua_State *lua_newstate (lua_Alloc f, void *ud);

    -Creates a new thread running in a new, independent state. -Returns NULL if it cannot create the thread or the state +Creates a new independent state and returns its main thread. +Returns NULL if it cannot create the state (due to lack of memory). The argument f is the allocator function; -Lua does all memory allocation for this state +Lua will do all memory allocation for this state through this function (see lua_Alloc). The second argument, ud, is an opaque pointer that Lua passes to the allocator in every call. @@ -4098,7 +4503,6 @@ but has an independent execution stack.

    -There is no explicit function to close or to destroy a thread. Threads are subject to garbage collection, like any Lua object. @@ -4106,34 +4510,43 @@ like any Lua object. -


    lua_newuserdata

    +


    lua_newuserdatauv

    [-0, +1, m] -

    void *lua_newuserdata (lua_State *L, size_t size);
    +
    void *lua_newuserdatauv (lua_State *L, size_t size, int nuvalue);
    + +

    +This function creates and pushes on the stack a new full userdata, +with nuvalue associated Lua values, called user values, +plus an associated block of raw memory with size bytes. +(The user values can be set and read with the functions +lua_setiuservalue and lua_getiuservalue.) +

    -This function allocates a new block of memory with the given size, -pushes onto the stack a new full userdata with the block address, -and returns this address. -The host program can freely use this memory. +The function returns the address of the block of memory. +Lua ensures that this address is valid as long as +the corresponding userdata is alive (see §2.5). +Moreover, if the userdata is marked for finalization (see §2.5.3), +its address is valid at least until the call to its finalizer.


    lua_next

    -[-1, +(2|0), e] +[-1, +(2|0), v]

    int lua_next (lua_State *L, int index);

    Pops a key from the stack, -and pushes a key–value pair from the table at the given index -(the "next" pair after the given key). +and pushes a key–value pair from the table at the given index, +the "next" pair after the given key. If there are no more elements in the table, -then lua_next returns 0 (and pushes nothing). +then lua_next returns 0 and pushes nothing.

    -A typical traversal looks like this: +A typical table traversal looks like this:

          /* table is in the stack at index 't' */
    @@ -4150,7 +4563,7 @@ A typical traversal looks like this:
     
     

    While traversing a table, -do not call lua_tolstring directly on a key, +avoid calling lua_tolstring directly on a key, unless you know that the key is actually a string. Recall that lua_tolstring may change the value at the given index; @@ -4158,6 +4571,8 @@ this confuses the next call to lua_next.

    +This function may raise an error if the given key +is neither nil nor present in the table. See function next for the caveats of modifying the table during its traversal. @@ -4185,15 +4600,14 @@ but that can be changed to a single float or a long double.

    int lua_numbertointeger (lua_Number n, lua_Integer *p);

    -Converts a Lua float to a Lua integer. -This macro assumes that n has an integral value. +Tries to convert a Lua float to a Lua integer; +the float n must have an integral value. If that value is within the range of Lua integers, it is converted to an integer and assigned to *p. The macro results in a boolean indicating whether the conversion was successful. (Note that this range test can be tricky to do -correctly without this macro, -due to roundings.) +correctly without this macro, due to rounding.)

    @@ -4208,7 +4622,7 @@ This macro may evaluate its arguments more than once.

    int lua_pcall (lua_State *L, int nargs, int nresults, int msgh);

    -Calls a function in protected mode. +Calls a function (or a callable object) in protected mode.

    @@ -4233,7 +4647,7 @@ Otherwise, msgh is the stack index of a message handler. (This index cannot be a pseudo-index.) In case of runtime errors, -this function will be called with the error object +this handler will be called with the error object and its return value will be the object returned on the stack by lua_pcall. @@ -4246,35 +4660,9 @@ since by then the stack has unwound.

    -The lua_pcall function returns one of the following constants -(defined in lua.h): - -

      - -
    • LUA_OK (0): -success.
    • - -
    • LUA_ERRRUN: -a runtime error. -
    • - -
    • LUA_ERRMEM: -memory allocation error. -For such errors, Lua does not call the message handler. -
    • - -
    • LUA_ERRERR: -error while running the message handler. -
    • - -
    • LUA_ERRGCMM: -error while running a __gc metamethod. -For such errors, Lua does not call the message handler -(as this kind of error typically has no relation -with the function being called). -
    • +The lua_pcall function returns one of the following status codes: +LUA_OK, LUA_ERRRUN, LUA_ERRMEM, or LUA_ERRERR. -
    @@ -4290,18 +4678,19 @@ with the function being called).

    This function behaves exactly like lua_pcall, -but allows the called function to yield (see §4.7). +except that it allows the called function to yield (see §4.5).


    lua_pop

    -[-n, +0, –] +[-n, +0, e]

    void lua_pop (lua_State *L, int n);

    Pops n elements from the stack. +It is implemented as a macro over lua_settop. @@ -4324,16 +4713,28 @@ Pushes a boolean value with value b onto the stack.

    Pushes a new C closure onto the stack. +This function receives a pointer to a C function +and pushes onto the stack a Lua value of type function that, +when called, invokes the corresponding C function. +The parameter n tells how many upvalues this function will have +(see §4.2). + + +

    +Any function to be callable by Lua must +follow the correct protocol to receive its parameters +and return its results (see lua_CFunction).

    When a C function is created, it is possible to associate some values with it, -thus creating a C closure (see §4.4); -these values are then accessible to the function whenever it is called. -To associate values with a C function, -first these values must be pushed onto the stack -(when there are multiple values, the first value is pushed first). +the so called upvalues; +these upvalues are then accessible to the function whenever it is called. +This association is called a C closure (see §4.2). +To create a C closure, +first the initial values for its upvalues must be pushed onto the stack. +(When there are multiple upvalues, the first value is pushed first.) Then lua_pushcclosure is called to create and push the C function onto the stack, with the argument n telling how many values will be @@ -4361,58 +4762,42 @@ In that case, it never raises a memory error.

    Pushes a C function onto the stack. -This function receives a pointer to a C function -and pushes onto the stack a Lua value of type function that, -when called, invokes the corresponding C function. - - -

    -Any function to be callable by Lua must -follow the correct protocol to receive its parameters -and return its results (see lua_CFunction). +This function is equivalent to lua_pushcclosure with no upvalues.


    lua_pushfstring

    -[-0, +1, e] +[-0, +1, v]

    const char *lua_pushfstring (lua_State *L, const char *fmt, ...);

    Pushes onto the stack a formatted string -and returns a pointer to this string. +and returns a pointer to this string (see §4.1.3). It is similar to the ISO C function sprintf, -but has some important differences: - -

      - -
    • -You do not have to allocate space for the result: +but has two important differences. +First, +you do not have to allocate space for the result; the result is a Lua string and Lua takes care of memory allocation (and deallocation, through garbage collection). -
    • - -
    • -The conversion specifiers are quite restricted. +Second, +the conversion specifiers are quite restricted. There are no flags, widths, or precisions. The conversion specifiers can only be '%%' (inserts the character '%'), '%s' (inserts a zero-terminated string, with no size restrictions), '%f' (inserts a lua_Number), '%I' (inserts a lua_Integer), -'%p' (inserts a pointer as a hexadecimal numeral), +'%p' (inserts a pointer), '%d' (inserts an int), '%c' (inserts an int as a one-byte character), and '%U' (inserts a long int as a UTF-8 byte sequence). -
    • -

    -Unlike other push functions, -this function checks for the stack space it needs, -including the slot for its result. +This function may raise errors due to memory overflow +or an invalid conversion specifier. @@ -4468,6 +4853,7 @@ light userdata with the same C address.

    This macro is equivalent to lua_pushstring, but should be used only when s is a literal string. +(Lua may optimize this case.) @@ -4480,7 +4866,7 @@ but should be used only when s is a literal string.

    Pushes the string pointed to by s with size len onto the stack. -Lua makes (or reuses) an internal copy of the given string, +Lua will make or reuse an internal copy of the given string, so the memory at s can be freed or reused immediately after the function returns. The string can contain any binary data, @@ -4488,7 +4874,7 @@ including embedded zeros.

    -Returns a pointer to the internal copy of the string. +Returns a pointer to the internal copy of the string (see §4.1.3). @@ -4523,13 +4909,13 @@ Pushes a float with value n onto the stack.

    Pushes the zero-terminated string pointed to by s onto the stack. -Lua makes (or reuses) an internal copy of the given string, +Lua will make or reuse an internal copy of the given string, so the memory at s can be freed or reused immediately after the function returns.

    -Returns a pointer to the internal copy of the string. +Returns a pointer to the internal copy of the string (see §4.1.3).

    @@ -4564,7 +4950,7 @@ onto the stack.


    lua_pushvfstring

    -[-0, +1, m] +[-0, +1, v]

    const char *lua_pushvfstring (lua_State *L,
                                   const char *fmt,
                                   va_list argp);
    @@ -4584,7 +4970,7 @@ instead of a variable number of arguments.

    Returns 1 if the two values in indices index1 and index2 are primitively equal -(that is, without calling the __eq metamethod). +(that is, equal without calling the __eq metamethod). Otherwise returns 0. Also returns 0 if any of the indices are not valid. @@ -4612,7 +4998,7 @@ Similar to lua_gettable, but does a raw Pushes onto the stack the value t[n], where t is the table at the given index. The access is raw, -that is, it does not invoke the __index metamethod. +that is, it does not use the __index metavalue.

    @@ -4631,7 +5017,7 @@ Pushes onto the stack the value t[k], where t is the table at the given index and k is the pointer p represented as a light userdata. The access is raw; -that is, it does not invoke the __index metamethod. +that is, it does not use the __index metavalue.

    @@ -4643,7 +5029,7 @@ Returns the type of the pushed value.


    lua_rawlen

    [-0, +0, –] -

    size_t lua_rawlen (lua_State *L, int index);
    +
    lua_Unsigned lua_rawlen (lua_State *L, int index);

    Returns the raw "length" of the value at the given index: @@ -4651,8 +5037,8 @@ for strings, this is the string length; for tables, this is the result of the length operator ('#') with no metamethods; for userdata, this is the size of the block of memory allocated -for the userdata; -for other values, it is 0. +for the userdata. +For other values, this call returns 0. @@ -4677,13 +5063,13 @@ Similar to lua_settable, but does a raw

    Does the equivalent of t[i] = v, where t is the table at the given index -and v is the value at the top of the stack. +and v is the value on the top of the stack.

    This function pops the value from the stack. The assignment is raw, -that is, it does not invoke the __newindex metamethod. +that is, it does not use the __newindex metavalue. @@ -4697,13 +5083,13 @@ that is, it does not invoke the __newindex metamethod. Does the equivalent of t[p] = v, where t is the table at the given index, p is encoded as a light userdata, -and v is the value at the top of the stack. +and v is the value on the top of the stack.

    This function pops the value from the stack. The assignment is raw, -that is, it does not invoke __newindex metamethod. +that is, it does not use the __newindex metavalue. @@ -4716,8 +5102,8 @@ that is, it does not invoke __newindex metamethod.

    The reader function used by lua_load. -Every time it needs another piece of the chunk, -lua_load calls the reader, +Every time lua_load needs another piece of the chunk, +it calls the reader, passing along its data parameter. The reader must return a pointer to a block of memory with a new piece of the chunk @@ -4775,9 +5161,29 @@ and then pops the top element. +


    lua_resetthread

    +[-0, +?, –] +

    int lua_resetthread (lua_State *L);
    + +

    +Resets a thread, cleaning its call stack and closing all pending +to-be-closed variables. +Returns a status code: +LUA_OK for no errors in the thread +(either the original error that stopped the thread or +errors in closing methods), +or an error status otherwise. +In case of error, +leaves the error object on the top of the stack. + + + + +


    lua_resume

    [-?, +?, –] -

    int lua_resume (lua_State *L, lua_State *from, int nargs);
    +
    int lua_resume (lua_State *L, lua_State *from, int nargs,
    +                          int *nresults);

    Starts and resumes a coroutine in the given thread L. @@ -4785,31 +5191,29 @@ Starts and resumes a coroutine in the given thread L.

    To start a coroutine, -you push onto the thread stack the main function plus any arguments; +you push the main function plus any arguments +onto the empty stack of the thread. then you call lua_resume, with nargs being the number of arguments. This call returns when the coroutine suspends or finishes its execution. -When it returns, the stack contains all values passed to lua_yield, -or all values returned by the body function. +When it returns, +*nresults is updated and +the top of the stack contains +the *nresults values passed to lua_yield +or returned by the body function. lua_resume returns LUA_YIELD if the coroutine yields, LUA_OK if the coroutine finishes its execution without errors, -or an error code in case of errors (see lua_pcall). - - -

    +or an error code in case of errors (see §4.4.1). In case of errors, -the stack is not unwound, -so you can use the debug API over it. -The error object is on the top of the stack. +the error object is on the top of the stack.

    To resume a coroutine, -you remove any results from the last lua_yield, -put on its stack only the values to -be passed as results from yield, +you remove the *nresults yielded values from its stack, +push the values to be passed as results from yield, and then call lua_resume. @@ -4861,7 +5265,7 @@ with user data ud.

    Does the equivalent to t[k] = v, where t is the value at the given index -and v is the value at the top of the stack. +and v is the value on the top of the stack.

    @@ -4892,7 +5296,7 @@ sets it as the new value of global name.

    Does the equivalent to t[n] = v, where t is the value at the given index -and v is the value at the top of the stack. +and v is the value on the top of the stack.

    @@ -4904,13 +5308,33 @@ for the "newindex" event (see §2.4). +


    lua_setiuservalue

    +[-1, +0, –] +

    int lua_setiuservalue (lua_State *L, int index, int n);
    + +

    +Pops a value from the stack and sets it as +the new n-th user value associated to the +full userdata at the given index. +Returns 0 if the userdata does not have that value. + + + + +


    lua_setmetatable

    [-1, +0, –] -

    void lua_setmetatable (lua_State *L, int index);
    +
    int lua_setmetatable (lua_State *L, int index);
    + +

    +Pops a table or nil from the stack and +sets that value as the new metatable for the value at the given index. +(nil means no metatable.) +

    -Pops a table from the stack and -sets it as the new metatable for the value at the given index. +(For historical reasons, this function returns an int, +which now is always 1.) @@ -4923,7 +5347,7 @@ sets it as the new metatable for the value at the given index.

    Does the equivalent to t[k] = v, where t is the value at the given index, -v is the value at the top of the stack, +v is the value on the top of the stack, and k is the value just below the top. @@ -4937,27 +5361,34 @@ for the "newindex" event (see §2.4).


    lua_settop

    -[-?, +?, –] +[-?, +?, e]

    void lua_settop (lua_State *L, int index);

    Accepts any index, or 0, and sets the stack top to this index. -If the new top is larger than the old one, +If the new top is greater than the old one, then the new elements are filled with nil. If index is 0, then all stack elements are removed. +

    +This function can run arbitrary code when removing an index +marked as to-be-closed from the stack. -


    lua_setuservalue

    -[-1, +0, –] -

    void lua_setuservalue (lua_State *L, int index);
    + + +

    lua_setwarnf

    +[-0, +0, –] +

    void lua_setwarnf (lua_State *L, lua_WarnFunction f, void *ud);

    -Pops a value from the stack and sets it as -the new value associated to the full userdata at the given index. +Sets the warning function to be used by Lua to emit warnings +(see lua_WarnFunction). +The ud parameter sets the value ud passed to +the warning function. @@ -4992,14 +5423,14 @@ Returns the status of the thread L.

    -The status can be 0 (LUA_OK) for a normal thread, +The status can be LUA_OK for a normal thread, an error code if the thread finished the execution of a lua_resume with an error, -or LUA_YIELD if the thread is suspended. +or LUA_YIELD if the thread is suspended.

    -You can only call functions in threads with status LUA_OK. +You can call functions only in threads with status LUA_OK. You can resume threads with status LUA_OK (to start a new coroutine) or LUA_YIELD (to resume a coroutine). @@ -5019,7 +5450,7 @@ and returns the total size of the string, that is, its length plus one. The conversion can result in an integer or a float, according to the lexical conventions of Lua (see §3.1). -The string may have leading and trailing spaces and a sign. +The string may have leading and trailing whitespaces and a sign. If the string is not a valid numeral, returns 0 and pushes nothing. (Note that the result can be used as a boolean, @@ -5060,6 +5491,43 @@ otherwise, returns NULL. +


    lua_toclose

    +[-0, +0, m] +

    void lua_toclose (lua_State *L, int index);
    + +

    +Marks the given index in the stack as a +to-be-closed slot (see §3.3.8). +Like a to-be-closed variable in Lua, +the value at that slot in the stack will be closed +when it goes out of scope. +Here, in the context of a C function, +to go out of scope means that the running function returns to Lua, +or there is an error, +or the slot is removed from the stack through +lua_settop or lua_pop, +or there is a call to lua_closeslot. +A slot marked as to-be-closed should not be removed from the stack +by any other function in the API except lua_settop or lua_pop, +unless previously deactivated by lua_closeslot. + + +

    +This function should not be called for an index +that is equal to or below an active to-be-closed slot. + + +

    +Note that, both in case of errors and of a regular return, +by the time the __close metamethod runs, +the C stack was already unwound, +so that any automatic C variable declared in the calling function +(e.g., a buffer) will be out of scope. + + + + +


    lua_tointeger

    [-0, +0, –]

    lua_Integer lua_tointeger (lua_State *L, int index);
    @@ -5111,18 +5579,12 @@ when lua_tolstring is applied to keys during a table traversal.)

    lua_tolstring returns a pointer -to a string inside the Lua state. +to a string inside the Lua state (see §4.1.3). This string always has a zero ('\0') after its last character (as in C), but can contain other zeros in its body. -

    -Because Lua has garbage collection, -there is no guarantee that the pointer returned by lua_tolstring -will be valid after the corresponding Lua value is removed from the stack. - - @@ -5165,7 +5627,7 @@ indicates whether the operation succeeded.

    Converts the value at the given index to a generic C pointer (void*). -The value can be a userdata, a table, a thread, or a function; +The value can be a userdata, a table, a thread, a string, or a function; otherwise, lua_topointer returns NULL. Different objects will give different pointers. There is no way to convert the pointer back to its original value. @@ -5209,9 +5671,9 @@ otherwise, the function returns NULL.

    If the value at the given index is a full userdata, -returns its block address. +returns its memory-block address. If the value is a light userdata, -returns its pointer. +returns its value (a pointer). Otherwise, returns NULL. @@ -5224,10 +5686,10 @@ Otherwise, returns NULL.

    Returns the type of the value in the given valid index, -or LUA_TNONE for a non-valid (but acceptable) index. +or LUA_TNONE for a non-valid but acceptable index. The types returned by lua_type are coded by the following constants defined in lua.h: -LUA_TNIL (0), +LUA_TNIL, LUA_TNUMBER, LUA_TBOOLEAN, LUA_TSTRING, @@ -5270,7 +5732,8 @@ The unsigned version of lua_Integer.

    Returns the pseudo-index that represents the i-th upvalue of -the running function (see §4.4). +the running function (see §4.2). +i must be in the range [1,256]. @@ -5278,16 +5741,47 @@ the running function (see §4.4).


    lua_version

    [-0, +0, –] -

    const lua_Number *lua_version (lua_State *L);
    +
    lua_Number lua_version (lua_State *L);
    + +

    +Returns the version number of this core. + + + + + +


    lua_WarnFunction

    +
    typedef void (*lua_WarnFunction) (void *ud, const char *msg, int tocont);
    + +

    +The type of warning functions, called by Lua to emit warnings. +The first parameter is an opaque pointer +set by lua_setwarnf. +The second parameter is the warning message. +The third parameter is a boolean that +indicates whether the message is +to be continued by the message in the next call. + + +

    +See warn for more details about warnings. + + + + + +


    lua_warning

    +[-0, +0, –] +

    void lua_warning (lua_State *L, const char *msg, int tocont);
    + +

    +Emits a warning with the given message. +A message in a call with tocont true should be +continued in another call to this function. +

    -Returns the address of the version number -(a C static variable) -stored in the Lua core. -When called with a valid lua_State, -returns the address of the version used to create that state. -When called with NULL, -returns the address of the version running the call. +See warn for more details about warnings. @@ -5301,11 +5795,11 @@ returns the address of the version running the call.

    The type of the writer function used by lua_dump. -Every time it produces another piece of chunk, -lua_dump calls the writer, +Every time lua_dump produces another piece of chunk, +it calls the writer, passing along the buffer to be written (p), its size (sz), -and the data parameter supplied to lua_dump. +and the ud parameter supplied to lua_dump.

    @@ -5335,22 +5829,24 @@ and pushes them onto the stack to.


    lua_yield

    -[-?, +?, e] +[-?, +?, v]

    int lua_yield (lua_State *L, int nresults);

    This function is equivalent to lua_yieldk, -but it has no continuation (see §4.7). +but it has no continuation (see §4.5). Therefore, when the thread resumes, it continues the function that called the function calling lua_yield. +To avoid surprises, +this function should be called only in a tail call.


    lua_yieldk

    -[-?, +?, e] +[-?, +?, v]

    int lua_yieldk (lua_State *L,
                     int nresults,
                     lua_KContext ctx,
    @@ -5371,7 +5867,7 @@ that will be passed as results to lua_resume<
     

    When the coroutine is resumed again, Lua calls the given continuation function k to continue -the execution of the C function that yielded (see §4.7). +the execution of the C function that yielded (see §4.5). This continuation function receives the same stack from the previous function, with the n results removed and @@ -5387,7 +5883,7 @@ when the coroutine eventually resumes, it continues executing the continuation function. However, there is one special case, which is when this function is called -from inside a line or a count hook (see §4.9). +from inside a line or a count hook (see §4.7). In that case, lua_yieldk should be called with no continuation (probably in the form of lua_yield) and no results, and the hook should return immediately after the call. @@ -5399,9 +5895,10 @@ of the (Lua) function that triggered the hook.

    This function can raise an error if it is called from a thread -with a pending C call with no continuation function, +with a pending C call with no continuation function +(what is called a C-call boundary), or it is called from a thread that is not running inside a resume -(e.g., the main thread). +(typically the main thread). @@ -5409,7 +5906,7 @@ or it is called from a thread that is not running inside a resume -

    4.9 – The Debug Interface

    +

    4.7 – The Debug Interface

    Lua has no built-in debugging facilities. @@ -5428,6 +5925,7 @@ that need "inside information" from the interpreter. const char *namewhat; /* (n) */ const char *what; /* (S) */ const char *source; /* (S) */ + size_t srclen; /* (S) */ int currentline; /* (l) */ int linedefined; /* (S) */ int lastlinedefined; /* (S) */ @@ -5435,6 +5933,8 @@ that need "inside information" from the interpreter. unsigned char nparams; /* (u) number of parameters */ char isvararg; /* (u) */ char istailcall; /* (t) */ + unsigned short ftransfer; /* (r) index of first value transferred */ + unsigned short ntransfer; /* (r) number of transferred values */ char short_src[LUA_IDSIZE]; /* (S) */ /* private part */ other fields @@ -5446,7 +5946,10 @@ information about a function or an activation record. lua_getstack fills only the private part of this structure, for later use. To fill the other fields of lua_Debug with useful information, -call lua_getinfo. +you must call lua_getinfo with an appropriate parameter. +(Specifically, to get a field, +you must add the letter between parentheses in the field's comment +to the parameter what of lua_getinfo.)

    @@ -5455,17 +5958,21 @@ The fields of lua_Debug have the following

    • source: -the name of the chunk that created the function. +the source of the chunk that created the function. If source starts with a '@', it means that the function was defined in a file where the file name follows the '@'. If source starts with a '=', -the remainder of its contents describe the source in a user-dependent manner. +the remainder of its contents describes the source in a user-dependent manner. Otherwise, the function was defined in a string where source is that string.
    • +
    • srclen: +The length of the string source. +
    • +
    • short_src: a "printable" version of source, to be used in error messages.
    • @@ -5521,7 +6028,7 @@ the number of upvalues of the function.
    • nparams: -the number of fixed parameters of the function +the number of parameters of the function (always 0 for C functions).
    • @@ -5530,6 +6037,24 @@ true if the function is a vararg function (always true for C functions). +
    • ftransfer: +the index in the stack of the first value being "transferred", +that is, parameters in a call or return values in a return. +(The other values are in consecutive indices.) +Using this index, you can access and modify these values +through lua_getlocal and lua_setlocal. +This field is only meaningful during a +call hook, denoting the first parameter, +or a return hook, denoting the first value being returned. +(For call hooks, this value is always 1.) +
    • + +
    • ntransfer: +The number of values being transferred (see previous item). +(For calls of Lua functions, +this value is always equal to nparams.) +
    • +
    @@ -5569,7 +6094,7 @@ Returns the current hook mask.

    lua_getinfo

    -[-(0|1), +(0|1|2), e] +[-(0|1), +(0|1|2), m]

    int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);

    @@ -5584,7 +6109,7 @@ given as argument to a hook (see lua_Hook).

    -To get information about a function you push it onto the stack +To get information about a function, you push it onto the stack and start the what string with the character '>'. (In that case, lua_getinfo pops the function from the top of the stack.) @@ -5601,11 +6126,25 @@ you can write the following code:

    Each character in the string what selects some fields of the structure ar to be filled or -a value to be pushed on the stack: +a value to be pushed on the stack. +(These characters are also documented in the declaration of +the structure lua_Debug, +between parentheses in the comments following each field.)

      -
    • 'n': fills in the field name and namewhat; +
    • 'f': +pushes onto the stack the function that is +running at the given level; +
    • + +
    • 'l': fills in the field currentline; +
    • + +
    • 'n': fills in the fields name and namewhat; +
    • + +
    • 'r': fills in the fields ftransfer and ntransfer;
    • 'S': @@ -5613,9 +6152,6 @@ fills in the fields source, short_src, linedefined, lastlinedefined, and what;
    • -
    • 'l': fills in the field currentline; -
    • -
    • 't': fills in the field istailcall;
    • @@ -5623,29 +6159,21 @@ fills in the fields source, short_src, nups, nparams, and isvararg; -
    • 'f': -pushes onto the stack the function that is -running at the given level; -
    • -
    • 'L': -pushes onto the stack a table whose indices are the -numbers of the lines that are valid on the function. -(A valid line is a line with some associated code, -that is, a line where you can put a break point. -Non-valid lines include empty lines and comments.) - - -

      +pushes onto the stack a table whose indices are +the lines on the function with some associated code, +that is, the lines where you can put a break point. +(Lines with no code include empty lines and comments.) If this option is given together with option 'f', its table is pushed after the function. +This is the only option that can raise a memory error.

    -This function returns 0 on error -(for instance, an invalid option in what). +This function returns 0 to signal an invalid option in what; +even then the valid options are handled correctly. @@ -5656,8 +6184,8 @@ This function returns 0 on error

    const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);

    -Gets information about a local variable of -a given activation record or a given function. +Gets information about a local variable or a temporary value +of a given activation record or a given function.

    @@ -5677,7 +6205,7 @@ and returns its name.

    In the second case, ar must be NULL and the function -to be inspected must be at the top of the stack. +to be inspected must be on the top of the stack. In this case, only parameters of Lua functions are visible (as there is no information about what variables are active) and no values are pushed onto the stack. @@ -5706,10 +6234,10 @@ an identification of the activation record of the function executing at a given level. Level 0 is the current running function, whereas level n+1 is the function that has called level n -(except for tail calls, which do not count on the stack). -When there are no errors, lua_getstack returns 1; -when called with a level greater than the stack depth, -it returns 0. +(except for tail calls, which do not count in the stack). +When called with a level greater than the stack depth, +lua_getstack returns 0; +otherwise it returns 1. @@ -5729,17 +6257,7 @@ when the index n is greater than the number of upvalues.

    -For C functions, this function uses the empty string "" -as a name for all upvalues. -(For Lua functions, -upvalues are the external local variables that the function uses, -and that are consequently included in its closure.) - - -

    -Upvalues have no particular order, -as they are active through the whole function. -They are numbered in an arbitrary order. +See debug.getupvalue for more information about upvalues. @@ -5816,31 +6334,28 @@ For each event, the hook is called as explained below:

    • The call hook: is called when the interpreter calls a function. -The hook is called just after Lua enters the new function, -before the function gets its arguments. +The hook is called just after Lua enters the new function.
    • The return hook: is called when the interpreter returns from a function. The hook is called just before Lua leaves the function. -There is no standard way to access the values -to be returned by the function.
    • The line hook: is called when the interpreter is about to start the execution of a new line of code, or when it jumps back in the code (even to the same line). -(This event only happens while Lua is executing a Lua function.) +This event only happens while Lua is executing a Lua function.
    • The count hook: is called after the interpreter executes every count instructions. -(This event only happens while Lua is executing a Lua function.) +This event only happens while Lua is executing a Lua function.

    -A hook is disabled by setting mask to zero. +Hooks are disabled by setting mask to zero. @@ -5852,7 +6367,7 @@ A hook is disabled by setting mask to zero.

    Sets the value of a local variable of a given activation record. -It assigns the value at the top of the stack +It assigns the value on the top of the stack to the variable and returns its name. It also pops the value from the stack. @@ -5864,7 +6379,7 @@ the number of active local variables.

    -Parameters ar and n are as in function lua_getlocal. +Parameters ar and n are as in the function lua_getlocal. @@ -5876,7 +6391,7 @@ Parameters ar and n are as in function lua_getupvalue. +Parameters funcindex and n are as in +the function lua_getupvalue. @@ -5911,7 +6427,8 @@ will return identical ids for those upvalue indices.

    -Parameters funcindex and n are as in function lua_getupvalue, +Parameters funcindex and n are as in +the function lua_getupvalue, but n cannot be greater than the number of upvalues. @@ -5935,6 +6452,8 @@ refer to the n2-th upvalue of the Lua closure at index funcin

    5 – The Auxiliary Library

    + +

    The auxiliary library provides several convenient functions @@ -5981,6 +6500,8 @@ always raise an error if the check is not satisfied. + +

    5.1 – Functions and Types

    @@ -6001,6 +6522,20 @@ Adds the byte c to the buffer B +


    luaL_addgsub

    +[-?, +?, m] +

    const void luaL_addgsub (luaL_Buffer *B, const char *s,
    +                         const char *p, const char *r);
    + +

    +Adds a copy of the string s to the buffer B (see luaL_Buffer), +replacing any occurrence of the string p +with the string r. + + + + +


    luaL_addlstring

    [-?, +?, m]

    void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l);
    @@ -6020,7 +6555,7 @@ The string can contain embedded zeros.
    void luaL_addsize (luaL_Buffer *B, size_t n);

    -Adds to the buffer B (see luaL_Buffer) +Adds to the buffer B a string of length n previously copied to the buffer area (see luaL_prepbuffer). @@ -6042,11 +6577,11 @@ to the buffer B


    luaL_addvalue

    -[-1, +?, m] +[-?, +?, m]

    void luaL_addvalue (luaL_Buffer *B);

    -Adds the value at the top of the stack +Adds the value on the top of the stack to the buffer B (see luaL_Buffer). Pops the value. @@ -6095,6 +6630,22 @@ This function never returns. +


    luaL_argexpected

    +[-0, +0, v] +

    void luaL_argexpected (lua_State *L,
    +                       int cond,
    +                       int arg,
    +                       const char *tname);
    + +

    +Checks whether cond is true. +If it is not, raises an error about the type of the argument arg +with a standard message (see luaL_typeerror). + + + + +


    luaL_Buffer

    typedef struct luaL_Buffer luaL_Buffer;
    @@ -6125,7 +6676,7 @@ This call leaves the final string on the top of the stack.

    -If you know beforehand the total size of the resulting string, +If you know beforehand the maximum size of the resulting string, you can use the buffer like this:

      @@ -6135,12 +6686,13 @@ you can use the buffer like this:
    • Then initialize it and preallocate a space of size sz with a call luaL_buffinitsize(L, &b, sz).
    • -
    • Then copy the string into that space.
    • +
    • Then produce the string into that space.
    • Finish by calling luaL_pushresultsize(&b, sz), where sz is the total size of the resulting string -copied into that space. +copied into that space (which may be less than or +equal to the preallocated size).
    @@ -6157,22 +6709,47 @@ when you call a buffer operation, the stack is at the same level it was immediately after the previous buffer operation. (The only exception to this rule is luaL_addvalue.) -After calling luaL_pushresult the stack is back to its -level when the buffer was initialized, +After calling luaL_pushresult, +the stack is back to its level when the buffer was initialized, plus the final string on its top. -

    luaL_buffinit

    +


    luaL_buffaddr

    [-0, +0, –] +

    char *luaL_buffaddr (luaL_Buffer *B);
    + +

    +Returns the address of the current content of buffer B +(see luaL_Buffer). +Note that any addition to the buffer may invalidate this address. + + + + + +


    luaL_buffinit

    +[-0, +?, –]

    void luaL_buffinit (lua_State *L, luaL_Buffer *B);

    -Initializes a buffer B. +Initializes a buffer B +(see luaL_Buffer). This function does not allocate any space; -the buffer must be declared as a variable +the buffer must be declared as a variable. + + + + + +


    luaL_bufflen

    +[-0, +0, –] +

    size_t luaL_bufflen (luaL_Buffer *B);
    + +

    +Returns the length of the current content of buffer B (see luaL_Buffer). @@ -6191,6 +6768,19 @@ Equivalent to the sequence +


    luaL_buffsub

    +[-?, +?, –] +

    void luaL_buffsub (luaL_Buffer *B, int n);
    + +

    +Removes n bytes from the the buffer B +(see luaL_Buffer). +The buffer must have at least that many bytes. + + + + +


    luaL_callmeta

    [-0, +(0|1), e]

    int luaL_callmeta (lua_State *L, int obj, const char *e);
    @@ -6206,7 +6796,7 @@ this function calls this field passing the object as its only argument. In this case this function returns true and pushes onto the stack the value returned by the call. If there is no metatable or no metamethod, -this function returns false (without pushing any value on the stack). +this function returns false without pushing any value on the stack. @@ -6231,7 +6821,7 @@ of any type (including nil) at position arg.

    Checks whether the function argument arg is an integer (or can be converted to an integer) -and returns this integer cast to a lua_Integer. +and returns this integer. @@ -6244,7 +6834,7 @@ and returns this integer cast to a lua_Integer Checks whether the function argument arg is a string and returns this string; -if l is not NULL fills *l +if l is not NULL fills its referent with the string's length. @@ -6262,7 +6852,7 @@ so all conversions and caveats of that function apply here.

    Checks whether the function argument arg is a number -and returns this number. +and returns this number converted to a lua_Number. @@ -6349,7 +6939,7 @@ See lua_type for the encoding of types for

    Checks whether the function argument arg is a userdata of the type tname (see luaL_newmetatable) and -returns the userdata address (see lua_touserdata). +returns the userdata's memory-block address (see lua_touserdata). @@ -6360,19 +6950,15 @@ returns the userdata address (see lua_touserdata

    void luaL_checkversion (lua_State *L);

    -Checks whether the core running the call, -the core that created the Lua state, -and the code making the call are all using the same version of Lua. -Also checks whether the core running the call -and the core that created the Lua state -are using the same address space. +Checks whether the code making the call and the Lua library being called +are using the same version of Lua and the same numeric types.


    luaL_dofile

    -[-0, +?, e] +[-0, +?, m]

    int luaL_dofile (lua_State *L, const char *filename);

    @@ -6382,8 +6968,8 @@ It is defined as the following macro:

          (luaL_loadfile(L, filename) || lua_pcall(L, 0, LUA_MULTRET, 0))
     

    -It returns false if there are no errors -or true in case of errors. +It returns LUA_OK if there are no errors, +or an error code in case of errors (see §4.4.1). @@ -6400,8 +6986,8 @@ It is defined as the following macro:

          (luaL_loadstring(L, str) || lua_pcall(L, 0, LUA_MULTRET, 0))
     

    -It returns false if there are no errors -or true in case of errors. +It returns LUA_OK if there are no errors, +or an error code in case of errors (see §4.4.1). @@ -6462,7 +7048,7 @@ file-related functions in the standard library

    Pushes onto the stack the field e from the metatable -of the object at index obj and returns the type of pushed value. +of the object at index obj and returns the type of the pushed value. If the object does not have a metatable, or if the metatable does not have this field, pushes nothing and returns LUA_TNIL. @@ -6476,9 +7062,9 @@ pushes nothing and returns LUA_TNIL.

    int luaL_getmetatable (lua_State *L, const char *tname);

    -Pushes onto the stack the metatable associated with name tname -in the registry (see luaL_newmetatable) -(nil if there is no metatable associated with that name). +Pushes onto the stack the metatable associated with the name tname +in the registry (see luaL_newmetatable), +or nil if there is no metatable associated with that name. Returns the type of the pushed value. @@ -6509,8 +7095,8 @@ and false if it creates a new table. const char *r);

    -Creates a copy of string s by replacing -any occurrence of the string p +Creates a copy of string s, +replacing any occurrence of the string p with the string r. Pushes the resulting string on the stack and returns it. @@ -6527,7 +7113,7 @@ Returns the "length" of the value at the given index as a number; it is equivalent to the '#' operator in Lua (see §3.4.7). Raises an error if the result of the operation is not an integer. -(This case only can happen through metamethods.) +(This case can only happen through metamethods.) @@ -6565,7 +7151,7 @@ buffer pointed to by buff with size sz. This function returns the same results as lua_load. name is the chunk name, used for debug information and error messages. -The string mode works as in function lua_load. +The string mode works as in the function lua_load. @@ -6597,14 +7183,12 @@ The first line in the file is ignored if it starts with a #.

    -The string mode works as in function lua_load. +The string mode works as in the function lua_load.

    -This function returns the same results as lua_load, -but it has an extra error code LUA_ERRFILE -for file-related errors -(e.g., it cannot open or read the file). +This function returns the same results as lua_load +or LUA_ERRFILE for file-related errors.

    @@ -6643,7 +7227,7 @@ it does not run it.

    Creates a new table and registers there -the functions in list l. +the functions in the list l.

    @@ -6692,11 +7276,11 @@ creates a new table to be used as a metatable for userdata, adds to this new table the pair __name = tname, adds to the registry the pair [tname] = new table, and returns 1. -(The entry __name is used by some error-reporting functions.)

    -In both cases pushes onto the stack the final value associated +In both cases, +the function pushes onto the stack the final value associated with tname in the registry. @@ -6710,10 +7294,9 @@ with tname in the registry.

    Creates a new Lua state. It calls lua_newstate with an -allocator based on the standard C realloc function -and then sets a panic function (see §4.6) that prints -an error message to the standard error output in case of fatal -errors. +allocator based on the standard C allocation functions +and then sets a warning function and a panic function (see §4.4) +that print messages to the standard error output.

    @@ -6736,7 +7319,7 @@ Opens all standard Lua libraries into the given state.


    luaL_opt

    -[-0, +0, e] +[-0, +0, –]

    T luaL_opt (L, func, arg, dflt);

    @@ -6749,7 +7332,7 @@ In words, if the argument arg is nil or absent, the macro results in the default dflt. Otherwise, it results in the result of calling func with the state L and the argument index arg as -parameters. +arguments. Note that it evaluates the expression dflt only if needed. @@ -6764,7 +7347,7 @@ Note that it evaluates the expression dflt only if needed.

    If the function argument arg is an integer -(or convertible to an integer), +(or it is convertible to an integer), returns this integer. If this argument is absent or is nil, returns d. @@ -6791,7 +7374,7 @@ Otherwise, raises an error.

    If l is not NULL, -fills the position *l with the result's length. +fills its referent with the result's length. If the result is NULL (only possible when returning d and d == NULL), its length is considered zero. @@ -6811,7 +7394,7 @@ so all conversions and caveats of that function apply here.

    If the function argument arg is a number, -returns this number. +returns this number as a lua_Number. If this argument is absent or is nil, returns d. Otherwise, raises an error. @@ -6865,6 +7448,17 @@ it to the buffer. +


    luaL_pushfail

    +[-0, +1, –] +

    void luaL_pushfail (lua_State *L);
    + +

    +Pushes the fail value onto the stack (see §6). + + + + +


    luaL_pushresult

    [-?, +1, m]

    void luaL_pushresult (luaL_Buffer *B);
    @@ -6895,20 +7489,20 @@ Equivalent to the sequence luaL_addsize

    Creates and returns a reference, in the table at index t, -for the object at the top of the stack (and pops the object). +for the object on the top of the stack (and pops the object).

    A reference is a unique integer key. -As long as you do not manually add integer keys into table t, +As long as you do not manually add integer keys into the table t, luaL_ref ensures the uniqueness of the key it returns. -You can retrieve an object referred by reference r +You can retrieve an object referred by the reference r by calling lua_rawgeti(L, t, r). -Function luaL_unref frees a reference and its associated object. +The function luaL_unref frees a reference.

    -If the object at the top of the stack is nil, +If the object on the top of the stack is nil, luaL_ref returns the constant LUA_REFNIL. The constant LUA_NOREF is guaranteed to be different from any reference returned by luaL_ref. @@ -6941,15 +7535,15 @@ in which both name and func are NULL. lua_CFunction openf, int glb);

    -If modname is not already present in package.loaded, -calls function openf with string modname as an argument -and sets the call result in package.loaded[modname], +If package.loaded[modname] is not true, +calls the function openf with the string modname as an argument +and sets the call result to package.loaded[modname], as if that function has been called through require.

    If glb is true, -also stores the module into global modname. +also stores the module into the global modname.

    @@ -6971,12 +7565,18 @@ Registers all functions in the array l

    When nup is not zero, -all functions are created sharing nup upvalues, -which must be previously pushed on the stack +all functions are created with nup upvalues, +initialized with copies of the nup values +previously pushed on the stack on top of the library table. These values are popped from the stack after the registration. +

    +A function with a NULL value represents a placeholder, +which is filled with false. + + @@ -6985,7 +7585,7 @@ These values are popped from the stack after the registration.

    void luaL_setmetatable (lua_State *L, const char *tname);

    -Sets the metatable of the object at the top of the stack +Sets the metatable of the object on the top of the stack as the metatable associated with name tname in the registry (see luaL_newmetatable). @@ -7000,8 +7600,8 @@ in the registry (see luaL_newmetatable } luaL_Stream;

    -The standard representation for file handles, -which is used by the standard I/O library. +The standard representation for file handles +used by the standard I/O library.

    @@ -7015,14 +7615,14 @@ The metatable is created by the I/O library

    This userdata must start with the structure luaL_Stream; it can contain other data after this initial structure. -Field f points to the corresponding C stream +The field f points to the corresponding C stream (or it can be NULL to indicate an incompletely created handle). -Field closef points to a Lua function +The field closef points to a Lua function that will be called to close the stream when the handle is closed or collected; this function receives the file handle as its sole argument and -must return either true (in case of success) -or nil plus an error message (in case of error). +must return either a true value, in case of success, +or a false value plus an error message, in case of error. Once Lua calls this field, it changes the field value to NULL to signal that the handle is closed. @@ -7052,7 +7652,7 @@ it returns NULL instead of raising an error. Converts any Lua value at the given index to a C string in a reasonable format. The resulting string is pushed onto the stack and also -returned by the function. +returned by the function (see §4.1.3). If len is not NULL, the function also sets *len with the string length. @@ -7074,7 +7674,7 @@ and uses the result of the call as its result.

    Creates and pushes a traceback of the stack L1. -If msg is not NULL it is appended +If msg is not NULL, it is appended at the beginning of the traceback. The level parameter tells at which level to start the traceback. @@ -7083,6 +7683,23 @@ to start the traceback. +


    luaL_typeerror

    +[-0, +0, v] +

    const char *luaL_typeerror (lua_State *L,
    +                                      int arg,
    +                                      const char *tname);
    + +

    +Raises a type error for the argument arg +of the C function that called it, +using a standard message; +tname is a "name" for the expected type. +This function never returns. + + + + +


    luaL_typename

    [-0, +0, –]

    const char *luaL_typename (lua_State *L, int index);
    @@ -7099,7 +7716,7 @@ Returns the name of the type of the value at the given index.
    void luaL_unref (lua_State *L, int t, int ref);

    -Releases reference ref from the table at index t +Releases the reference ref from the table at index t (see luaL_ref). The entry is removed from the table, so that the referred object can be collected. @@ -7140,22 +7757,41 @@ This function is used to build a prefix for error messages. -

    6 – Standard Libraries

    +

    6 – The Standard Libraries

    + +

    The standard Lua libraries provide useful functions -that are implemented directly through the C API. +that are implemented in C through the C API. Some of these functions provide essential services to the language (e.g., type and getmetatable); -others provide access to "outside" services (e.g., I/O); +others provide access to outside services (e.g., I/O); and others could be implemented in Lua itself, -but are quite useful or have critical performance requirements that +but that for different reasons deserve an implementation in C (e.g., table.sort).

    All libraries are implemented through the official C API and are provided as separate C modules. +Unless otherwise noted, +these library functions do not adjust its number of arguments +to its expected parameters. +For instance, a function documented as foo(arg) +should not be called without an argument. + + +

    +The notation fail means a false value representing +some kind of failure. +(Currently, fail is equal to nil, +but that may change in future versions. +The recommendation is to always test the success of these functions +with (not status), instead of (status == nil).) + + +

    Currently, Lua has the following standard libraries:

      @@ -7197,7 +7833,7 @@ the host program can open them individually by using luaopen_package (for the package library), luaopen_coroutine (for the coroutine library), luaopen_string (for the string library), -luaopen_utf8 (for the UTF8 library), +luaopen_utf8 (for the UTF-8 library), luaopen_table (for the table library), luaopen_math (for the mathematical library), luaopen_io (for the I/O library), @@ -7207,6 +7843,8 @@ These functions are declared in lualib.h + +

      6.1 – Basic Functions

      @@ -7221,7 +7859,7 @@ implementations for some of its facilities.

      -Calls error if +Raises an error if the value of its argument v is false (i.e., nil or false); otherwise, returns all its arguments. In case of error, @@ -7242,77 +7880,88 @@ It performs different functions according to its first argument, opt

    • "collect": -performs a full garbage-collection cycle. +Performs a full garbage-collection cycle. This is the default option.
    • "stop": -stops automatic execution of the garbage collector. +Stops automatic execution of the garbage collector. The collector will run only when explicitly invoked, until a call to restart it.
    • "restart": -restarts automatic execution of the garbage collector. +Restarts automatic execution of the garbage collector.
    • "count": -returns the total memory in use by Lua in Kbytes. +Returns the total memory in use by Lua in Kbytes. The value has a fractional part, so that it multiplied by 1024 -gives the exact number of bytes in use by Lua -(except for overflows). +gives the exact number of bytes in use by Lua.
    • "step": -performs a garbage-collection step. +Performs a garbage-collection step. The step "size" is controlled by arg. With a zero value, the collector will perform one basic (indivisible) step. For non-zero values, the collector will perform as if that amount of memory -(in KBytes) had been allocated by Lua. +(in Kbytes) had been allocated by Lua. Returns true if the step finished a collection cycle.
    • -
    • "setpause": -sets arg as the new value for the pause of -the collector (see §2.5). -Returns the previous value for pause. +
    • "isrunning": +Returns a boolean that tells whether the collector is running +(i.e., not stopped).
    • -
    • "setstepmul": -sets arg as the new value for the step multiplier of -the collector (see §2.5). -Returns the previous value for step. +
    • "incremental": +Change the collector mode to incremental. +This option can be followed by three numbers: +the garbage-collector pause, +the step multiplier, +and the step size (see §2.5.1). +A zero means to not change that value.
    • -
    • "isrunning": -returns a boolean that tells whether the collector is running -(i.e., not stopped). +
    • "generational": +Change the collector mode to generational. +This option can be followed by two numbers: +the garbage-collector minor multiplier +and the major multiplier (see §2.5.2). +A zero means to not change that value.
    • -
    +

    +See §2.5 for more details about garbage collection +and some of these options. + + +

    +This function should not be called by a finalizer. +


    dofile ([filename])

    -Opens the named file and executes its contents as a Lua chunk. +Opens the named file and executes its content as a Lua chunk. When called without arguments, -dofile executes the contents of the standard input (stdin). +dofile executes the content of the standard input (stdin). Returns all values returned by the chunk. In case of errors, dofile propagates the error -to its caller (that is, dofile does not run in protected mode). +to its caller. +(That is, dofile does not run in protected mode.)


    error (message [, level])

    -Terminates the last protected function called -and returns message as the error object. -Function error never returns. +Raises an error (see §2.3) with message as the error object. +This function never returns.

    @@ -7367,7 +8016,7 @@ so that the construction

    will iterate over the key–value pairs (1,t[1]), (2,t[2]), ..., -up to the first nil value. +up to the first absent index. @@ -7391,29 +8040,35 @@ A return of an empty string, nil, or no value signals the end of the chun

    If there are no syntactic errors, -returns the compiled chunk as a function; -otherwise, returns nil plus the error message. +load returns the compiled chunk as a function; +otherwise, it returns fail plus the error message.

    -If the resulting function has upvalues, -the first upvalue is set to the value of env, -if that parameter is given, -or to the value of the global environment. -Other upvalues are initialized with nil. -(When you load a main chunk, +When you load a main chunk, the resulting function will always have exactly one upvalue, the _ENV variable (see §2.2). However, when you load a binary chunk created from a function (see string.dump), -the resulting function can have an arbitrary number of upvalues.) +the resulting function can have an arbitrary number of upvalues, +and there is no guarantee that its first upvalue will be +the _ENV variable. +(A non-main function may not even have an _ENV upvalue.) + + +

    +Regardless, if the resulting function has any upvalues, +its first upvalue is set to the value of env, +if that parameter is given, +or to the value of the global environment. +Other upvalues are initialized with nil. All upvalues are fresh, that is, they are not shared with any other function.

    chunkname is used as the name of the chunk for error messages -and debug information (see §4.9). +and debug information (see §4.7). When absent, it defaults to chunk, if chunk is a string, or to "=(load)" otherwise. @@ -7429,9 +8084,11 @@ The default is "bt".

    -Lua does not check the consistency of binary chunks. -Maliciously crafted binary chunks can crash -the interpreter. +It is safe to load malformed binary chunks; +load signals an appropriate error. +However, +Lua does not check the consistency of the code inside binary chunks; +running maliciously crafted bytecode can crash the interpreter. @@ -7457,7 +8114,7 @@ if no file name is given. Allows a program to traverse all fields of a table. Its first argument is a table and its second argument is an index in this table. -next returns the next index of the table +A call to next returns the next index of the table and its associated value. When called with nil as its second argument, next returns an initial index @@ -7478,11 +8135,10 @@ use a numerical for.)

    -The behavior of next is undefined if, -during the traversal, -you assign any value to a non-existent field in the table. +You should not assign any value to a non-existent field in a table +during its traversal. You may however modify existing fields. -In particular, you may clear existing fields. +In particular, you may set existing fields to nil. @@ -7520,16 +8176,17 @@ the table during its traversal.

    -Calls function f with +Calls the function f with the given arguments in protected mode. This means that any error inside f is not propagated; instead, pcall catches the error and returns a status code. Its first result is the status code (a boolean), -which is true if the call succeeds without errors. +which is true if the call succeeds without errors. In such case, pcall also returns all results from the call, after this first result. -In case of any error, pcall returns false plus the error message. +In case of any error, pcall returns false plus the error object. +Note that errors caught by pcall do not call a message handler. @@ -7538,8 +8195,12 @@ In case of any error, pcall returns false plus the error mes


    print (···)

    Receives any number of arguments and prints their values to stdout, -using the tostring function to convert each argument to a string. -print is not intended for formatted output, +converting each argument to a string +following the same rules of tostring. + + +

    +The function print is not intended for formatted output, but only as a quick way to show a value, for instance for debugging. For complete control over the output, @@ -7560,7 +8221,7 @@ Returns a boolean.


    rawget (table, index)

    Gets the real value of table[index], -without invoking the __index metamethod. +without using the __index metavalue. table must be a table; index may be any value. @@ -7580,7 +8241,7 @@ Returns an integer.


    rawset (table, index, value)

    Sets the real value of table[index] to value, -without invoking the __newindex metamethod. +without using the __newindex metavalue. table must be a table, index any value different from nil and NaN, and value any Lua value. @@ -7612,8 +8273,6 @@ and select returns the total number of extra arguments it received.

    Sets the metatable for the given table. -(To change the metatable of other types from Lua code, -you must use the debug library (§6.10).) If metatable is nil, removes the metatable of the given table. If the original metatable has a __metatable field, @@ -7624,6 +8283,11 @@ raises an error. This function returns table. +

    +To change the metatable of other types from Lua code, +you must use the debug library (§6.10). + +

    @@ -7636,13 +8300,13 @@ When called with no base, If the argument is already a number or a string convertible to a number, then tonumber returns this number; -otherwise, it returns nil. +otherwise, it returns fail.

    The conversion of strings can result in integers or floats, according to the lexical conventions of Lua (see §3.1). -(The string may have leading and trailing spaces and a sign.) +The string may have leading and trailing spaces and a sign.

    @@ -7654,17 +8318,18 @@ In bases above 10, the letter 'A' (in either upper or lower ca represents 10, 'B' represents 11, and so forth, with 'Z' representing 35. If the string e is not a valid numeral in the given base, -the function returns nil. +the function returns fail.


    tostring (v)

    + + +

    Receives a value of any type and converts it to a string in a human-readable format. -(For complete control of how numbers are converted, -use string.format.)

    @@ -7672,12 +8337,23 @@ If the metatable of v has a __tostring field, then tostring calls the corresponding value with v as argument, and uses the result of the call as its result. +Otherwise, if the metatable of v has a __name field +with a string value, +tostring may use that string in its final result. + + +

    +For complete control of how numbers are converted, +use string.format.


    type (v)

    + + +

    Returns the type of its only argument, coded as a string. The possible results of this function are "nil" (a string, not the value nil), @@ -7699,7 +8375,30 @@ and "userdata".

    A global variable (not a function) that holds a string containing the running Lua version. -The current value of this variable is "Lua 5.3". +The current value of this variable is "Lua 5.4". + + + + +

    +


    warn (msg1, ···)

    + + +

    +Emits a warning with a message composed by the concatenation +of all its arguments (which should be strings). + + +

    +By convention, +a one-piece message starting with '@' +is intended to be a control message, +which is a message to the warning system itself. +In particular, the standard warning function in Lua +recognizes the control messages "@off", +to stop the emission of warnings, +and "@on", to (re)start the emission; +it ignores unknown control messages. @@ -7726,6 +8425,25 @@ which come inside the table coroutine. See §2.6 for a general description of coroutines. +

    +


    coroutine.close (co)

    + + +

    +Closes coroutine co, +that is, +closes all its pending to-be-closed variables +and puts the coroutine in a dead state. +The given coroutine must be dead or suspended. +In case of error +(either the original error that stopped the coroutine or +errors in closing methods), +returns false plus the error object; +otherwise returns true. + + + +


    coroutine.create (f)

    @@ -7740,15 +8458,16 @@ an object with type "thread".

    -


    coroutine.isyieldable ()

    +

    coroutine.isyieldable ([co])

    -Returns true when the running coroutine can yield. +Returns true when the coroutine co can yield. +The default for co is the running coroutine.

    -A running coroutine is yieldable if it is not the main thread and +A coroutine is yieldable if it is not the main thread and it is not inside a non-yieldable C function. @@ -7787,7 +8506,7 @@ If there is any error,

    Returns the running coroutine plus a boolean, -true when the running coroutine is the main one. +true when the running coroutine is the main one. @@ -7797,9 +8516,10 @@ true when the running coroutine is the main one.

    -Returns the status of coroutine co, as a string: +Returns the status of the coroutine co, as a string: "running", -if the coroutine is running (that is, it called status); +if the coroutine is running +(that is, it is the one that called status); "suspended", if the coroutine is suspended in a call to yield, or if it has not started running yet; "normal" if the coroutine is active but not running @@ -7815,14 +8535,15 @@ or if it has stopped with an error.

    -Creates a new coroutine, with body f. +Creates a new coroutine, with body f; f must be a function. Returns a function that resumes the coroutine each time it is called. -Any arguments passed to the function behave as the +Any arguments passed to this function behave as the extra arguments to resume. -Returns the same values returned by resume, +The function returns the same values returned by resume, except the first boolean. -In case of error, propagates the error. +In case of error, +the function closes the coroutine and propagates the error. @@ -7848,7 +8569,7 @@ The package library provides basic facilities for loading modules in Lua. It exports one function directly in the global environment: require. -Everything else is exported in a table package. +Everything else is exported in the table package.

    @@ -7861,13 +8582,17 @@ The function starts by looking into the pack to determine whether modname is already loaded. If it is, then require returns the value stored at package.loaded[modname]. +(The absence of a second result in this case +signals that this call did not have to load the module.) Otherwise, it tries to find a loader for the module.

    To find a loader, -require is guided by the package.searchers sequence. -By changing this sequence, +require is guided by the table package.searchers. +Each item in this table is a search function, +that searches for the module in a particular way. +By changing this table, we can change how require looks for a module. The following explanation is based on the default configuration for package.searchers. @@ -7888,9 +8613,14 @@ it tries an all-in-one loader (see Once a loader is found, require calls the loader with two arguments: -modname and an extra value dependent on how it got the loader. -(If the loader came from a file, -this extra value is the file name.) +modname and an extra value, +a loader data, +also returned by the searcher. +The loader data can be any value useful to the module; +for the default searchers, +it indicates where the loader was found. +(For instance, if the loader came from a file, +this extra value is the file path.) If the loader returns any non-nil value, require assigns the returned value to package.loaded[modname]. If the loader does not return a non-nil value and @@ -7898,6 +8628,9 @@ has not assigned any value to package.loaded[modname], then require assigns true to this entry. In any case, require returns the final value of package.loaded[modname]. +Besides that value, require also returns as a second result +the loader data returned by the searcher, +which indicates how require found the module.

    @@ -7945,13 +8678,14 @@ Default is '-'.

  • -The path used by require to search for a C loader. +A string with the path used by require +to search for a C loader.

    Lua initializes the C path package.cpath in the same way it initializes the Lua path package.path, -using the environment variable LUA_CPATH_5_3, +using the environment variable LUA_CPATH_5_4, or the environment variable LUA_CPATH, or a default path defined in luaconf.h. @@ -8017,6 +8751,18 @@ As such, it is only available on some platforms plus other Unix systems that support the dlfcn standard). +

    +This function is inherently insecure, +as it allows Lua to call any function in any readable dynamic +library in the system. +(Lua calls any function assuming the function +has a proper prototype and respects a proper protocol +(see lua_CFunction). +Therefore, +calling an arbitrary function in an arbitrary dynamic library +more often than not results in an access violation.) + +

    @@ -8024,16 +8770,17 @@ plus other Unix systems that support the dlfcn standard).

    -The path used by require to search for a Lua loader. +A string with the path used by require +to search for a Lua loader.

    At start-up, Lua initializes this variable with -the value of the environment variable LUA_PATH_5_3 or +the value of the environment variable LUA_PATH_5_4 or the environment variable LUA_PATH or with a default path defined in luaconf.h, if those environment variables are not defined. -Any ";;" in the value of the environment variable +A ";;" in the value of the environment variable is replaced by the default path. @@ -8061,7 +8808,7 @@ table used by require.

    -A table used by require to control how to load modules. +A table used by require to control how to find modules.

    @@ -8069,10 +8816,14 @@ Each entry in this table is a searcher function. When looking for a module, require calls each of these searchers in ascending order, with the module name (the argument given to require) as its -sole parameter. -The function can return another function (the module loader) -plus an extra value that will be passed to that loader, -or a string explaining why it did not find that module +sole argument. +If the searcher finds the module, +it returns another function, the module loader, +plus an extra value, a loader data, +that will be passed to that loader and +returned as a second result by require. +If it cannot find the module, +it returns a string explaining why (or nil if it has nothing to say). @@ -8135,9 +8886,15 @@ with each submodule keeping its original open function.

    All searchers except the first one (preload) return as the extra value -the file name where the module was found, +the file path where the module was found, as returned by package.searchpath. -The first searcher returns no extra value. +The first searcher always returns the string ":preload:". + + +

    +Searchers should raise no errors and have no side effects in Lua. +(They may have side effects in C, +for instance by linking the application with a library.) @@ -8178,7 +8935,7 @@ will try to open the files

    Returns the resulting name of the first file that it can open in read mode (after closing the file), -or nil plus an error message if none succeeds. +or fail plus an error message if none succeeds. (This error message lists all file names it tried to open.) @@ -8189,6 +8946,8 @@ or nil plus an error message if none succeeds.

    6.4 – String Manipulation

    + +

    This library provides generic functions for string manipulation, such as finding and extracting substrings, and pattern matching. @@ -8262,8 +9021,10 @@ to save space.

    Functions with upvalues have only their number of upvalues saved. When (re)loaded, -those upvalues receive fresh instances containing nil. -(You can use the debug library to serialize +those upvalues receive fresh instances. +(See the load function for details about +how these upvalues are initialized. +You can use the debug library to serialize and reload the upvalues of a function in a way adequate to your needs.) @@ -8279,15 +9040,14 @@ Looks for the first match of pattern (see §6.4.1) in the string s. If it finds a match, then find returns the indices of s where this occurrence starts and ends; -otherwise, it returns nil. +otherwise, it returns fail. A third, optional numeric argument init specifies where to start the search; its default value is 1 and can be negative. -A value of true as a fourth, optional argument plain +A true as a fourth, optional argument plain turns off the pattern matching facilities, so the function does a plain "find substring" operation, with no characters in pattern being considered magic. -Note that if plain is given, then init must be given as well.

    @@ -8305,16 +9065,24 @@ after the two indices.

    Returns a formatted version of its variable number of arguments -following the description given in its first argument (which must be a string). +following the description given in its first argument, +which must be a string. The format string follows the same rules as the ISO C function sprintf. -The only differences are that the options/modifiers -*, h, L, l, n, -and p are not supported -and that there is an extra option, q. +The only differences are that the conversion specifiers and modifiers +F, n, *, h, L, and l are not supported +and that there is an extra specifier, q. +Both width and precision, when present, +are limited to two digits.

    -The q option formats a string between double quotes, +The specifier q formats booleans, nil, numbers, and strings +in a way that the result is a valid constant in Lua source code. +Booleans and nil are written in the obvious way +(true, false, nil). +Floats are written in hexadecimal, +to preserve full precision. +A string is written between double quotes, using escape sequences when necessary to ensure that it can safely be read back by the Lua interpreter. For instance, the call @@ -8327,38 +9095,53 @@ may produce the string:

          "a string with \"quotes\" and \
           new line"
    -
    +

    +This specifier does not support modifiers (flags, width, precision). +

    -Options +The conversion specifiers A, a, E, e, f, G, and g all expect a number as argument. -Options c, d, +The specifiers c, d, i, o, u, X, and x expect an integer. When Lua is compiled with a C89 compiler, -options A and a (hexadecimal floats) -do not support any modifier (flags, width, length). +the specifiers A and a (hexadecimal floats) +do not support modifiers.

    -Option s expects a string; +The specifier s expects a string; if its argument is not a string, it is converted to one following the same rules of tostring. -If the option has any modifier (flags, width, length), -the string argument should not contain embedded zeros. +If the specifier has any modifier, +the corresponding string argument should not contain embedded zeros. + + +

    +The specifier p formats the pointer +returned by lua_topointer. +That gives a unique string identifier for tables, userdata, +threads, strings, and functions. +For other values (numbers, nil, booleans), +this specifier results in a string representing +the pointer NULL.

    -


    string.gmatch (s, pattern)

    +

    string.gmatch (s, pattern [, init])

    Returns an iterator function that, each time it is called, returns the next captures from pattern (see §6.4.1) over the string s. If pattern specifies no captures, then the whole match is produced in each call. +A third, optional numeric argument init specifies +where to start the search; +its default value is 1 and can be negative.

    @@ -8407,9 +9190,9 @@ If repl is a string, then its value is used for replacement. The character % works as an escape character: any sequence in repl of the form %d, with d between 1 and 9, -stands for the value of the d-th captured substring. -The sequence %0 stands for the whole match. -The sequence %% stands for a single %. +stands for the value of the d-th captured substring; +the sequence %0 stands for the whole match; +the sequence %% stands for a single %.

    @@ -8459,15 +9242,18 @@ Here are some examples: end) --> x="4+5 = 9" - local t = {name="lua", version="5.3"} + local t = {name="lua", version="5.4"} x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t) - --> x="lua-5.3.tar.gz" + --> x="lua-5.4.tar.gz"


    string.len (s)

    + + +

    Receives a string and returns its length. The empty string "" has length 0. Embedded zeros are counted, @@ -8478,6 +9264,9 @@ so "a\000bc\000" has length 5.


    string.lower (s)

    + + +

    Receives a string and returns a copy of this string with all uppercase letters changed to lowercase. All other characters are left unchanged. @@ -8488,11 +9277,14 @@ The definition of what an uppercase letter is depends on the current locale.


    string.match (s, pattern [, init])

    + + +

    Looks for the first match of -pattern (see §6.4.1) in the string s. +the pattern (see §6.4.1) in the string s. If it finds one, then match returns the captures from the pattern; -otherwise it returns nil. +otherwise it returns fail. If pattern specifies no captures, then the whole match is returned. A third, optional numeric argument init specifies @@ -8508,7 +9300,7 @@ its default value is 1 and can be negative.

    Returns a binary string containing the values v1, v2, etc. -packed (that is, serialized in binary form) +serialized in binary form (packed) according to the format string fmt (see §6.4.2). @@ -8529,6 +9321,9 @@ The format string cannot have the variable-length options


    string.rep (s, n [, sep])

    + + +

    Returns a string that is the concatenation of n copies of the string s separated by the string sep. The default value for sep is the empty string @@ -8545,6 +9340,9 @@ with a single call to this function.)


    string.reverse (s)

    + + +

    Returns a string that is the string s reversed. @@ -8552,6 +9350,9 @@ Returns a string that is the string s reversed.


    string.sub (s, i [, j])

    + + +

    Returns the substring of s that starts at i and continues until j; i and j can be negative. @@ -8595,6 +9396,9 @@ this function also returns the index of the first unread byte in s.


    string.upper (s)

    + + +

    Receives a string and returns a copy of this string with all lowercase letters changed to uppercase. All other characters are left unchanged. @@ -8604,8 +9408,12 @@ The definition of what a lowercase letter is depends on the current locale. + +

    6.4.1 – Patterns

    + +

    Patterns in Lua are described by regular strings, which are interpreted as patterns by the pattern-matching functions @@ -8618,6 +9426,8 @@ This section describes the syntax and the meaning + +

    Character Class:

    A character class is used to represent a set of characters. The following combinations are allowed in describing a character class: @@ -8657,8 +9467,7 @@ represents the character x. This is the standard way to escape the magic characters. Any non-alphanumeric character (including all punctuation characters, even the non-magical) -can be preceded by a '%' -when used to represent itself in a pattern. +can be preceded by a '%' to represent itself in a pattern.

  • [set]: @@ -8680,7 +9489,7 @@ the lowercase letters plus the '-' character.

    You can put a closing square bracket in a set by positioning it as the first character in the set. -You can put an hyphen in a set +You can put a hyphen in a set by positioning it as the first or the last character in the set. (You can also use an escape for both cases.) @@ -8723,19 +9532,19 @@ which matches any single character in the class;

  • a single character class followed by '*', -which matches zero or more repetitions of characters in the class. +which matches sequences of zero or more characters in the class. These repetition items will always match the longest possible sequence;
  • a single character class followed by '+', -which matches one or more repetitions of characters in the class. +which matches sequences of one or more characters in the class. These repetition items will always match the longest possible sequence;
  • a single character class followed by '-', -which also matches zero or more repetitions of characters in the class. +which also matches sequences of zero or more characters in the class. Unlike '*', these repetition items will always match the shortest possible sequence;
  • @@ -8799,13 +9608,13 @@ that match captures are stored (captured) for future use. Captures are numbered according to their left parentheses. For instance, in the pattern "(a*(.)%w(%s*))", the part of the string matching "a*(.)%w(%s*)" is -stored as the first capture (and therefore has number 1); +stored as the first capture, and therefore has number 1; the character matching "." is captured with number 2, and the part matching "%s*" has number 3.

    -As a special case, the empty capture () captures +As a special case, the capture () captures the current string position (a number). For instance, if we apply the pattern "()aa()" on the string "flaaap", there will be two captures: 3 and 5. @@ -8814,6 +9623,32 @@ string "flaaap", there will be two captures: 3 and 5. +

    Multiple matches:

    +The function string.gsub and the iterator string.gmatch +match multiple occurrences of the given pattern in the subject. +For these functions, +a new match is considered valid only +if it ends at least one byte after the end of the previous match. +In other words, the pattern machine never accepts the +empty string as a match immediately after another match. +As an example, +consider the results of the following code: + +

    +     > string.gsub("abc", "()a*()", print);
    +     --> 1   2
    +     --> 3   3
    +     --> 4   4
    +

    +The second and third results come from Lua matching an empty +string after 'b' and another one after 'c'. +Lua does not match an empty string after 'a', +because it would end at the same position of the previous match. + + + + +

    6.4.2 – Format Strings for Pack and Unpack

    @@ -8860,13 +9695,13 @@ coded as an unsigned integer with n bytes
  • Xop: an empty item that aligns according to option op (which is otherwise ignored)
  • -
  • ' ': (empty space) ignored
  • +
  • ' ': (space) ignored
  • (A "[n]" means an optional integral numeral.) Except for padding, spaces, and configurations (options "xX <=>!"), -each option corresponds to an argument (in string.pack) -or a result (in string.unpack). +each option corresponds to an argument in string.pack +or a result in string.unpack.

    @@ -8875,6 +9710,8 @@ For options "!n", "sn", "i All integral options check overflows; string.pack checks whether the given value fits in the given size; string.unpack checks whether the read value fits in a Lua integer. +For the unsigned options, +Lua integers are treated as unsigned values too.

    @@ -8884,6 +9721,13 @@ with maximum alignment of 1 (no alignment) and native endianness. +

    +Native endianness assumes that the whole system is +either big or little endian. +The packing functions will not emulate correctly the behavior +of mixed-endian formats. + +

    Alignment works as follows: For each option, @@ -8897,7 +9741,7 @@ option "s" follows the alignment of its starting integer.

    All padding is filled with zeros by string.pack -(and ignored by string.unpack). +and ignored by string.unpack. @@ -8925,8 +9769,30 @@ As in the string library, negative indices count from the end of the string. +

    +Functions that create byte sequences +accept all values up to 0x7FFFFFFF, +as defined in the original UTF-8 specification; +that implies byte sequences of up to six bytes. + + +

    +Functions that interpret byte sequences only accept +valid sequences (well formed and not overlong). +By default, they only accept byte sequences +that result in valid Unicode code points, +rejecting values greater than 10FFFF and surrogates. +A boolean argument lax, when available, +lifts these checks, +so that all values up to 0x7FFFFFFF are accepted. +(Not well formed and overlong sequences are still rejected.) + +


    utf8.char (···)

    + + +

    Receives zero or more integers, converts each one to its corresponding UTF-8 byte sequence and returns a string with the concatenation of all these sequences. @@ -8936,7 +9802,10 @@ and returns a string with the concatenation of all these sequences.


    utf8.charpattern

    -The pattern (a string, not a function) "[\0-\x7F\xC2-\xF4][\x80-\xBF]*" + + +

    +The pattern (a string, not a function) "[\0-\x7F\xC2-\xFD][\x80-\xBF]*" (see §6.4.1), which matches exactly one UTF-8 byte sequence, assuming that the subject is a valid UTF-8 string. @@ -8945,7 +9814,7 @@ assuming that the subject is a valid UTF-8 string.

    -


    utf8.codes (s)

    +

    utf8.codes (s [, lax])

    @@ -8954,7 +9823,7 @@ Returns values so that the construction

          for p, c in utf8.codes(s) do body end
     

    -will iterate over all characters in string s, +will iterate over all UTF-8 characters in string s, with p being the position (in bytes) and c the code point of each character. It raises an error if it meets any invalid byte sequence. @@ -8963,8 +9832,11 @@ It raises an error if it meets any invalid byte sequence.

    -


    utf8.codepoint (s [, i [, j]])

    -Returns the codepoints (as integers) from all characters in s +

    utf8.codepoint (s [, i [, j [, lax]]])

    + + +

    +Returns the code points (as integers) from all characters in s that start between byte position i and j (both included). The default for i is 1 and for j is i. It raises an error if it meets any invalid byte sequence. @@ -8973,18 +9845,24 @@ It raises an error if it meets any invalid byte sequence.

    -


    utf8.len (s [, i [, j]])

    +

    utf8.len (s [, i [, j [, lax]]])

    + + +

    Returns the number of UTF-8 characters in string s that start between positions i and j (both inclusive). The default for i is 1 and for j is -1. If it finds any invalid byte sequence, -returns a false value plus the position of the first invalid byte. +returns fail plus the position of the first invalid byte.


    utf8.offset (s, n [, i])

    + + +

    Returns the position (in bytes) where the encoding of the n-th character of s (counting from position i) starts. @@ -8995,7 +9873,7 @@ so that utf8.offset(s, -n) gets the offset of the n-th character from the end of the string. If the specified character is neither in the subject nor right after its end, -the function returns nil. +the function returns fail.

    @@ -9052,7 +9930,7 @@ shifting up the elements list[pos], list[pos+1], ···, list[#list]. The default value for pos is #list+1, so that a call table.insert(t,x) inserts x at the end -of list t. +of the list t. @@ -9062,7 +9940,7 @@ of list t.

    -Moves elements from table a1 to table a2, +Moves elements from the table a1 to the table a2, performing the equivalent to the following multiple assignment: a2[t],··· = a1[f],···,a1[e]. @@ -9082,9 +9960,10 @@ Returns the destination table a2.

    -Returns a new table with all parameters stored into keys 1, 2, etc. -and with a field "n" with the total number of parameters. -Note that the resulting table may not be a sequence. +Returns a new table with all arguments stored into keys 1, 2, etc. +and with a field "n" with the total number of arguments. +Note that the resulting table may not be a sequence, +if some arguments are nil. @@ -9101,14 +9980,13 @@ it shifts down the elements list[pos+1], list[pos+2], ···, list[#list] and erases element list[#list]; The index pos can also be 0 when #list is 0, -or #list + 1; -in those cases, the function erases the element list[pos]. +or #list + 1.

    The default value for pos is #list, so that a call table.remove(l) removes the last element -of list l. +of the list l. @@ -9118,28 +9996,28 @@ of list l.

    -Sorts list elements in a given order, in-place, +Sorts the list elements in a given order, in-place, from list[1] to list[#list]. If comp is given, then it must be a function that receives two list elements and returns true when the first element must come -before the second in the final order -(so that, after the sort, -i < j implies not comp(list[j],list[i])). +before the second in the final order, +so that, after the sort, +i <= j implies not comp(list[j],list[i]). If comp is not given, then the standard Lua operator < is used instead.

    -Note that the comp function must define -a strict partial order over the elements in the list; -that is, it must be asymmetric and transitive. -Otherwise, no valid sort may be possible. +The comp function must define a consistent order; +more formally, the function must define a strict weak order. +(A weak order is similar to a total order, +but it can equate different elements for comparison purposes.)

    The sort algorithm is not stable: -elements considered equal by the given order +Different elements considered equal by the given order may have their relative positions changed by the sort. @@ -9171,9 +10049,9 @@ This library provides basic mathematical functions. It provides all its functions and constants inside the table math. Functions with the annotation "integer/float" give integer results for integer arguments -and float results for float (or mixed) arguments. -Rounding functions -(math.ceil, math.floor, and math.modf) +and float results for non-integer arguments. +The rounding functions +math.ceil, math.floor, and math.modf return an integer when the result fits in the range of an integer, or a float otherwise. @@ -9183,7 +10061,7 @@ or a float otherwise.

    -Returns the absolute value of x. (integer/float) +Returns the maximum value between x and -x. (integer/float) @@ -9215,9 +10093,9 @@ Returns the arc sine of x (in radians).

    Returns the arc tangent of y/x (in radians), -but uses the signs of both parameters to find the +but uses the signs of both arguments to find the quadrant of the result. -(It also handles correctly the case of x being zero.) +It also handles correctly the case of x being zero.

    @@ -9233,7 +10111,7 @@ returns the arc tangent of y.

    -Returns the smallest integral value larger than or equal to x. +Returns the smallest integral value greater than or equal to x. @@ -9274,7 +10152,7 @@ Returns the value ex

    -Returns the largest integral value smaller than or equal to x. +Returns the largest integral value less than or equal to x. @@ -9296,7 +10174,7 @@ that rounds the quotient towards zero. (integer/float)

    The float value HUGE_VAL, -a value larger than any other numeric value. +a value greater than any other numeric value. @@ -9319,7 +10197,7 @@ The default for base is e

    Returns the argument with the maximum value, -according to the Lua operator <. (integer/float) +according to the Lua operator <. @@ -9337,7 +10215,7 @@ An integer with the maximum value for an integer.

    Returns the argument with the minimum value, -according to the Lua operator <. (integer/float) +according to the Lua operator <. @@ -9391,25 +10269,59 @@ in the range [0,1). When called with two integers m and n, math.random returns a pseudo-random integer with uniform distribution in the range [m, n]. -(The value n-m cannot be negative and must fit in a Lua integer.) -The call math.random(n) is equivalent to math.random(1,n). +The call math.random(n), for a positive n, +is equivalent to math.random(1,n). +The call math.random(0) produces an integer with +all bits (pseudo)random. + + +

    +This function uses the xoshiro256** algorithm to produce +pseudo-random 64-bit integers, +which are the results of calls with argument 0. +Other results (ranges and floats) +are unbiased extracted from these integers.

    -This function is an interface to the underling -pseudo-random generator function provided by C. +Lua initializes its pseudo-random generator with the equivalent of +a call to math.randomseed with no arguments, +so that math.random should generate +different sequences of results each time the program runs.

    -


    math.randomseed (x)

    +

    math.randomseed ([x [, y]])

    -Sets x as the "seed" -for the pseudo-random generator: +When called with at least one argument, +the integer parameters x and y are +joined into a 128-bit seed that +is used to reinitialize the pseudo-random generator; equal seeds produce equal sequences of numbers. +The default for y is zero. + + +

    +When called with no arguments, +Lua generates a seed with +a weak attempt for randomness. + + +

    +This function returns the two seed components +that were effectively used, +so that setting them again repeats the sequence. + + +

    +To ensure a required level of randomness to the initial state +(or contrarily, to have a deterministic sequence, +for instance when debugging a program), +you should call math.randomseed with explicit arguments. @@ -9452,7 +10364,7 @@ Returns the tangent of x (assumed to be in radians).

    If the value x is convertible to an integer, returns that integer. -Otherwise, returns nil. +Otherwise, returns fail. @@ -9464,7 +10376,7 @@ Otherwise, returns nil.

    Returns "integer" if x is an integer, "float" if it is a float, -or nil if x is not a number. +or fail if x is not a number. @@ -9475,7 +10387,7 @@ or nil if x is not a number.

    Returns a boolean, -true if and only if integer m is below integer n when +true if and only if integer m is below integer n when they are compared as unsigned integers. @@ -9491,7 +10403,7 @@ The I/O library provides two different styles for file manipulation. The first one uses implicit file handles; that is, there are operations to set a default input file and a default output file, -and all input/output operations are over these default files. +and all input/output operations are done over these default files. The second style uses explicit file handles. @@ -9503,6 +10415,12 @@ the operation io.open returns a file han and then all operations are supplied as methods of the file handle. +

    +The metatable for file handles provides metamethods +for __gc and __close that try +to close the file when called. + +

    The table io also provides three predefined file handles with their usual meanings from C: @@ -9512,10 +10430,10 @@ The I/O library never closes these files.

    Unless otherwise stated, -all I/O functions return nil on failure -(plus an error message as a second result and -a system-dependent error code as a third result) -and some value different from nil on success. +all I/O functions return fail on failure, +plus an error message as a second result and +a system-dependent error code as a third result, +and some non-false value on success. On non-POSIX systems, the computation of the error message and error code in case of errors @@ -9553,7 +10471,7 @@ When called with a file name, it opens the named file (in text mode), and sets its handle as the default input file. When called with a file handle, it simply sets this file handle as the default input file. -When called without parameters, +When called without arguments, it returns the current default input file. @@ -9572,19 +10490,27 @@ instead of returning an error code. Opens the given file name in read mode and returns an iterator function that works like file:lines(···) over the opened file. -When the iterator function detects the end of file, -it returns no values (to finish the loop) and automatically closes the file. +When the iterator function fails to read any value, +it automatically closes the file. +Besides the iterator function, +io.lines returns three other values: +two nil values as placeholders, +plus the created file handle. +Therefore, when used in a generic for loop, +the file is closed also if the loop is interrupted by an +error or a break.

    The call io.lines() (with no file name) is equivalent -to io.input():lines("*l"); +to io.input():lines("l"); that is, it iterates over the lines of the default input file. -In this case it does not close the file when the loop ends. +In this case, the iterator does not close the file when the loop ends.

    -In case of errors this function raises the error, +In case of errors opening the file, +this function raises the error, instead of returning an error code. @@ -9639,7 +10565,7 @@ on all platforms.

    -Starts program prog in a separated process and returns +Starts the program prog in a separated process and returns a file handle that you can use to read data from this program (if mode is "r", the default) or to write data to this program @@ -9679,7 +10605,7 @@ and it is automatically removed when the program ends. Checks whether obj is a valid file handle. Returns the string "file" if obj is an open file handle, "closed file" if obj is a closed file handle, -or nil if obj is not a file handle. +or fail if obj is not a file handle. @@ -9744,11 +10670,6 @@ Unlike io.lines, this function does not when the loop ends. -

    -In case of errors this function raises the error, -instead of returning an error code. - -

    @@ -9760,10 +10681,10 @@ Reads the file file, according to the given formats, which specify what to read. For each format, the function returns a string or a number with the characters read, -or nil if it cannot read data with the specified format. +or fail if it cannot read data with the specified format. (In this latter case, the function does not read subsequent formats.) -When called without formats, +When called without arguments, it uses a default format that reads the next line (see below). @@ -9776,36 +10697,38 @@ The available formats are

  • "n": reads a numeral and returns it as a float or an integer, following the lexical conventions of Lua. -(The numeral may have leading spaces and a sign.) +(The numeral may have leading whitespaces and a sign.) This format always reads the longest input sequence that is a valid prefix for a numeral; if that prefix does not form a valid numeral -(e.g., an empty string, "0x", or "3.4e-"), -it is discarded and the function returns nil. +(e.g., an empty string, "0x", or "3.4e-") +or it is too long (more than 200 characters), +it is discarded and the format returns fail.
  • "a": reads the whole file, starting at the current position. -On end of file, it returns the empty string. +On end of file, it returns the empty string; +this format never fails.
  • "l": reads the next line skipping the end of line, -returning nil on end of file. +returning fail on end of file. This is the default format.
  • "L": reads the next line keeping the end-of-line character (if present), -returning nil on end of file. +returning fail on end of file.
  • number: reads a string with up to this number of bytes, -returning nil on end of file. +returning fail on end of file. If number is zero, it reads nothing and returns an empty string, -or nil on end of file. +or fail on end of file.
  • @@ -9831,7 +10754,7 @@ specified by the string whence, as follows:

    In case of success, seek returns the final file position, measured in bytes from the beginning of the file. -If seek fails, it returns nil, +If seek fails, it returns fail, plus a string describing the error. @@ -9853,31 +10776,25 @@ end of the file, and returns its size.

    -Sets the buffering mode for an output file. +Sets the buffering mode for a file. There are three available modes:

      +
    • "no": no buffering.
    • +
    • "full": full buffering.
    • +
    • "line": line buffering.
    • +
    -
  • "no": -no buffering; the result of any output operation appears immediately. -
  • - -
  • "full": -full buffering; output operation is performed only -when the buffer is full or when -you explicitly flush the file (see io.flush). -
  • +

    +For the last two cases, +size is a hint for the size of the buffer, in bytes. +The default is an appropriate size. -

  • "line": -line buffering; output is buffered until a newline is output -or there is any input from some special files -(such as a terminal device). -
  • -

    -For the last two cases, size -specifies the size of the buffer, in bytes. -The default is an appropriate size. +

    +The specific behavior of each mode is non portable; +check the underlying ISO C function setvbuf in your platform for +more details. @@ -9893,7 +10810,6 @@ The arguments must be strings or numbers.

    In case of success, this function returns file. -Otherwise it returns nil plus a string describing the error. @@ -9913,7 +10829,8 @@ This library is implemented through table os.

    Returns an approximation of the amount in seconds of CPU time -used by the program. +used by the program, +as returned by the underlying ISO C function clock. @@ -9941,7 +10858,8 @@ After this optional character, if format is the string "*t", then date returns a table with the following fields: year, month (1–12), day (1–31), -hour (0–23), min (0–59), sec (0–61), +hour (0–23), min (0–59), +sec (0–61, due to leap seconds), wday (weekday, 1–7, Sunday is 1), yday (day of the year, 1–366), and isdst (daylight saving flag, a boolean). @@ -9956,10 +10874,9 @@ formatted according to the same rules as the ISO C function strftime<

    -When called without arguments, -date returns a reasonable date and time representation that depends on -the host system and on the current locale. -(More specifically, os.date() is equivalent to os.date("%c").) +If format is absent, it defaults to "%c", +which gives a human-readable date and time representation +using the current locale.

    @@ -9993,7 +10910,7 @@ This function is equivalent to the ISO C function system. It passes command to be executed by an operating system shell. Its first result is true if the command terminated successfully, -or nil otherwise. +or fail otherwise. After this first result the function returns a string plus a number, as follows: @@ -10046,8 +10963,8 @@ closes the Lua state before exiting.

    -Returns the value of the process environment variable varname, -or nil if the variable is not defined. +Returns the value of the process environment variable varname +or fail if the variable is not defined. @@ -10059,7 +10976,7 @@ or nil if the variable is not defined.

    Deletes the file (or empty directory, on POSIX systems) with the given name. -If this function fails, it returns nil, +If this function fails, it returns fail plus a string describing the error and the error code. Otherwise, it returns true. @@ -10072,7 +10989,7 @@ Otherwise, it returns true.

    Renames the file or directory named oldname to newname. -If this function fails, it returns nil, +If this function fails, it returns fail, plus a string describing the error and the error code. Otherwise, it returns true. @@ -10091,7 +11008,7 @@ Sets the current locale of the program. "monetary", "numeric", or "time"; the default category is "all". The function returns the name of the new locale, -or nil if the request cannot be honored. +or fail if the request cannot be honored.

    @@ -10132,11 +11049,12 @@ For a description of these fields, see the os.date<

    -The values in these fields do not need to be inside their valid ranges. +When the function is called, +the values in these fields do not need to be inside their valid ranges. For instance, if sec is -10, -it means -10 seconds from the time specified by the other fields; +it means 10 seconds before the time specified by the other fields; if hour is 1000, -it means +1000 hours from the time specified by the other fields. +it means 1000 hours after the time specified by the other fields.

    @@ -10149,6 +11067,14 @@ and the number returned by time can be used only as an argument to os.date and os.difftime. +

    +When called with a table, +os.time also normalizes all the fields +documented in the os.date function, +so that they represent the same time as before the call +but with values inside their valid ranges. + +

    @@ -10163,7 +11089,7 @@ and explicitly removed when no longer needed.

    -On POSIX systems, +In POSIX systems, this function also creates a file with that name, to avoid security risks. (Someone else might create the file with wrong permissions @@ -10187,7 +11113,7 @@ which automatically removes the file when the program ends.

    This library provides -the functionality of the debug interface (§4.9) to Lua programs. +the functionality of the debug interface (§4.7) to Lua programs. You should exert care when using this library. Several of its functions violate basic assumptions about Lua code @@ -10236,8 +11162,12 @@ within any function and so have no direct access to local variables.

    Returns the current hook settings of the thread, as three values: the current hook function, the current hook mask, -and the current hook count -(as set by the debug.sethook function). +and the current hook count, +as set by the debug.sethook function. + + +

    +Returns fail if there is no active hook. @@ -10254,10 +11184,10 @@ which means the function running at level f of the call stack of the given thread: level 0 is the current function (getinfo itself); level 1 is the function that called getinfo -(except for tail calls, which do not count on the stack); +(except for tail calls, which do not count in the stack); and so on. -If f is a number larger than the number of active functions, -then getinfo returns nil. +If f is a number greater than the number of active functions, +then getinfo returns fail.

    @@ -10293,7 +11223,7 @@ about the print function. This function returns the name and the value of the local variable with index local of the function at level f of the stack. This function accesses not only explicit local variables, -but also parameters, temporaries, etc. +but also parameters and temporary values.

    @@ -10301,9 +11231,12 @@ The first parameter or local variable has index 1, and so on, following the order that they are declared in the code, counting only the variables that are active in the current scope of the function. -Negative indices refer to vararg parameters; --1 is the first vararg parameter. -The function returns nil if there is no variable with the given index, +Compile-time constants may not appear in this listing, +if they were optimized away by the compiler. +Negative indices refer to vararg arguments; +-1 is the first vararg argument. +The function returns fail +if there is no variable with the given index, and raises an error when called with a level out of range. (You can call debug.getinfo to check whether the level is valid.) @@ -10338,7 +11271,7 @@ or nil if it does not have a metatable.

    -Returns the registry table (see §4.5). +Returns the registry table (see §4.3). @@ -10350,25 +11283,37 @@ Returns the registry table (see §4.5).

    This function returns the name and the value of the upvalue with index up of the function f. -The function returns nil if there is no upvalue with the given index. +The function returns fail +if there is no upvalue with the given index.

    -Variable names starting with '(' (open parenthesis) -represent variables with no known names +(For Lua functions, +upvalues are the external local variables that the function uses, +and that are consequently included in its closure.) + + +

    +For C functions, this function uses the empty string "" +as a name for all upvalues. + + +

    +Variable name '?' (interrogation mark) +represents variables with no known names (variables from chunks saved without debug information).

    -


    debug.getuservalue (u)

    +

    debug.getuservalue (u, n)

    -Returns the Lua value associated to u. -If u is not a full userdata, -returns nil. +Returns the n-th user value associated +to the userdata u plus a boolean, +false if the userdata does not have that value. @@ -10378,7 +11323,7 @@ returns nil.

    -Sets the given function as a hook. +Sets the given function as the debug hook. The string mask and the number count describe when the hook will be called. The string mask may have any combination of the following characters, @@ -10402,16 +11347,15 @@ When called without arguments,

    When the hook is called, its first parameter is a string describing the event that has triggered its call: -"call" (or "tail call"), -"return", +"call", "tail call", "return", "line", and "count". For line events, the hook also gets the new line number as its second parameter. Inside a hook, you can call getinfo with level 2 to get more information about -the running function -(level 0 is the getinfo function, -and level 1 is the hook function). +the running function. +(Level 0 is the getinfo function, +and level 1 is the hook function.) @@ -10423,7 +11367,7 @@ and level 1 is the hook function).

    This function assigns the value value to the local variable with index local of the function at level level of the stack. -The function returns nil if there is no local +The function returns fail if there is no local variable with the given index, and raises an error when called with a level out of range. (You can call getinfo to check whether the level is valid.) @@ -10456,25 +11400,30 @@ Returns value.

    This function assigns the value value to the upvalue with index up of the function f. -The function returns nil if there is no upvalue +The function returns fail if there is no upvalue with the given index. Otherwise, it returns the name of the upvalue. +

    +See debug.getupvalue for more information about upvalues. + +

    -


    debug.setuservalue (udata, value)

    +

    debug.setuservalue (udata, value, n)

    Sets the given value as -the Lua value associated to the given udata. +the n-th user value associated to the given udata. udata must be a full userdata.

    -Returns udata. +Returns udata, +or fail if the userdata does not have that value. @@ -10541,7 +11490,7 @@ An interpreter for Lua as a standalone language, called simply lua, is provided with the standard distribution. The standalone interpreter includes -all standard libraries, including the debug library. +all standard libraries. Its usage is:

    @@ -10550,13 +11499,15 @@ Its usage is:
     The options are:
     
     
      -
    • -e stat: executes string stat;
    • -
    • -l mod: "requires" mod;
    • -
    • -i: enters interactive mode after running script;
    • -
    • -v: prints version information;
    • -
    • -E: ignores environment variables;
    • -
    • --: stops handling options;
    • -
    • -: executes stdin as a file and stops handling options.
    • +
    • -e stat: execute string stat;
    • +
    • -i: enter interactive mode after running script;
    • +
    • -l mod: "require" mod and assign the + result to global mod;
    • +
    • -v: print version information;
    • +
    • -E: ignore environment variables;
    • +
    • -W: turn warnings on;
    • +
    • --: stop handling options;
    • +
    • -: execute stdin as a file and stop handling options.

    After handling its options, lua runs the given script. When called without arguments, @@ -10566,8 +11517,8 @@ and as lua - otherwise.

    -When called without option -E, -the interpreter checks for an environment variable LUA_INIT_5_3 +When called without the option -E, +the interpreter checks for an environment variable LUA_INIT_5_4 (or LUA_INIT if the versioned name is not defined) before running any argument. If the variable content has the format @filename, @@ -10576,23 +11527,22 @@ Otherwise, lua executes the string itself.

    -When called with option -E, -besides ignoring LUA_INIT, -Lua also ignores -the values of LUA_PATH and LUA_CPATH, -setting the values of -package.path and package.cpath -with the default paths defined in luaconf.h. +When called with the option -E, +Lua does not consult any environment variables. +In particular, +the values of package.path and package.cpath +are set with the default paths defined in luaconf.h.

    -All options are handled in order, except -i and -E. +The options -e, -l, and -W are handled in +the order they appear. For instance, an invocation like

    -     $ lua -e'a=1' -e 'print(a)' script.lua
    +     $ lua -e 'a=1' -llib1 script.lua
     

    -will first set a to 1, then print the value of a, +will first set a to 1, then require the library lib1, and finally run the file script.lua with no arguments. (Here $ is the shell prompt. Your prompt may be different.) @@ -10629,10 +11579,10 @@ For instance, the call

    will print "-e". If there is a script, -the script is called with parameters +the script is called with arguments arg[1], ···, arg[#arg]. -(Like all chunks in Lua, -the script is compiled as a vararg function.) +Like all chunks in Lua, +the script is compiled as a vararg function.

    @@ -10663,6 +11613,8 @@ has a metamethod __tostring, the interpreter calls this metamethod to produce the final message. Otherwise, the interpreter converts the error object to a string and adds a stack traceback to it. +When warnings are on, +they are simply printed in the standard error output.

    @@ -10676,8 +11628,7 @@ calling os.exit to terminate.

    To allow the use of Lua as a script interpreter in Unix systems, -the standalone interpreter skips -the first line of a chunk if it starts with #. +Lua skips the first line of a file chunk if it starts with #. Therefore, Lua scripts can be made into executable programs by using chmod +x and the #! form, as in @@ -10685,7 +11636,7 @@ as in

          #!/usr/local/bin/lua
     

    -(Of course, +Of course, the location of the Lua interpreter may be different in your machine. If lua is in your PATH, then @@ -10693,19 +11644,31 @@ then

          #!/usr/bin/env lua
     

    -is a more portable solution.) +is a more portable solution.

    8 – Incompatibilities with the Previous Version

    + +

    Here we list the incompatibilities that you may find when moving a program -from Lua 5.2 to Lua 5.3. +from Lua 5.3 to Lua 5.4. + + +

    You can avoid some incompatibilities by compiling Lua with appropriate options (see file luaconf.h). However, all these compatibility options will be removed in the future. +More often than not, +compatibility issues arise when these compatibility options +are removed. +So, whenever you have the chance, +you should try to test your code with a version of Lua compiled +with all compatibility options turned off. +That will ease transitions to newer versions of Lua.

    @@ -10714,7 +11677,7 @@ do not imply source-code changes in a program, such as the numeric values for constants or the implementation of functions as macros. Therefore, -you should not assume that binaries are compatible between +you should never assume that binaries are compatible between different Lua versions. Always recompile clients of the Lua API when using a new version. @@ -10732,49 +11695,57 @@ change between versions. -

    8.1 – Changes in the Language

    + + +

    8.1 – Incompatibilities in the Language

    • -The main difference between Lua 5.2 and Lua 5.3 is the -introduction of an integer subtype for numbers. -Although this change should not affect "normal" computations, -some computations -(mainly those that involve some kind of overflow) -can give different results. - - -

      -You can fix these differences by forcing a number to be a float -(in Lua 5.2 all numbers were float), -in particular writing constants with an ending .0 -or using x = x + 0.0 to convert a variable. -(This recommendation is only for a quick fix -for an occasional incompatibility; -it is not a general guideline for good programming. -For good programming, -use floats where you need floats -and integers where you need integers.) +The coercion of strings to numbers in +arithmetic and bitwise operations +has been removed from the core language. +The string library does a similar job +for arithmetic (but not for bitwise) operations +using the string metamethods. +However, unlike in previous versions, +the new implementation preserves the implicit type of the numeral +in the string. +For instance, the result of "1" + "2" now is an integer, +not a float.

    • -The conversion of a float to a string now adds a .0 suffix -to the result if it looks like an integer. -(For instance, the float 2.0 will be printed as 2.0, -not as 2.) -You should always use an explicit format -when you need a specific format for numbers. +Literal decimal integer constants that overflow are read as floats, +instead of wrapping around. +You can use hexadecimal notation for such constants if you +want the old behavior +(reading them as integers with wrap around). +
    • +
    • +The use of the __lt metamethod to emulate __le +has been removed. +When needed, this metamethod must be explicitly defined. +
    • -

      -(Formally this is not an incompatibility, -because Lua does not specify how numbers are formatted as strings, -but some programs assumed a specific format.) +

    • +The semantics of the numerical for loop +over integers changed in some details. +In particular, the control variable never wraps around. +
    • + +
    • +A label for a goto cannot be declared where a label with the same +name is visible, even if this other label is declared in an enclosing +block.
    • -The generational mode for the garbage collector was removed. -(It was an experimental feature in Lua 5.2.) +When finalizing an object, +Lua does not ignore __gc metamethods that are not functions. +Any value will be called, if present. +(Non-callable values will generate a warning, +like any other error when calling a finalizer.)
    @@ -10782,61 +11753,43 @@ The generational mode for the garbage collector was removed. -

    8.2 – Changes in the Libraries

    +

    8.2 – Incompatibilities in the Libraries

    • -The bit32 library has been deprecated. -It is easy to require a compatible external library or, -better yet, to replace its functions with appropriate bitwise operations. -(Keep in mind that bit32 operates on 32-bit integers, -while the bitwise operators in Lua 5.3 operate on Lua integers, -which by default have 64 bits.) -
    • - -
    • -The Table library now respects metamethods -for setting and getting elements. -
    • - -
    • -The ipairs iterator now respects metamethods and -its __ipairs metamethod has been deprecated. +The function print does not call tostring +to format its arguments; +instead, it has this functionality hardwired. +You should use __tostring to modify how values are printed.
    • -Option names in io.read do not have a starting '*' anymore. -For compatibility, Lua will continue to accept (and ignore) this character. +The pseudo-random number generator used by the function math.random +now starts with a somewhat random seed. +Moreover, it uses a different algorithm.
    • -The following functions were deprecated in the mathematical library: -atan2, cosh, sinh, tanh, pow, -frexp, and ldexp. -You can replace math.pow(x,y) with x^y; -you can replace math.atan2 with math.atan, -which now accepts one or two parameters; -you can replace math.ldexp(x,exp) with x * 2.0^exp. -For the other operations, -you can either use an external library or -implement them in Lua. +By default, the decoding functions in the utf8 library +do not accept surrogates as valid code points. +An extra parameter in these functions makes them more permissive.
    • -The searcher for C loaders used by require -changed the way it handles versioned names. -Now, the version should come after the module name -(as is usual in most other tools). -For compatibility, that searcher still tries the old format -if it cannot find an open function according to the new style. -(Lua 5.2 already worked that way, -but it did not document the change.) +The options "setpause" and "setstepmul" +of the function collectgarbage are deprecated. +You should use the new option "incremental" to set them.
    • -The call collectgarbage("count") now returns only one result. -(You can compute that second result from the fractional part -of the first result.) +The function io.lines now returns four values, +instead of just one. +That can be a problem when it is used as the sole +argument to another function that has optional parameters, +such as in load(io.lines(filename, "L")). +To fix that issue, +you can wrap the call into parentheses, +to adjust its number of results to one.
    @@ -10844,37 +11797,54 @@ of the first result.) -

    8.3 – Changes in the API

    +

    8.3 – Incompatibilities in the API

    • -Continuation functions now receive as parameters what they needed -to get through lua_getctx, -so lua_getctx has been removed. -Adapt your code accordingly. +Full userdata now has an arbitrary number of associated user values. +Therefore, the functions lua_newuserdata, +lua_setuservalue, and lua_getuservalue were +replaced by lua_newuserdatauv, +lua_setiuservalue, and lua_getiuservalue, +which have an extra argument. + + +

      +For compatibility, the old names still work as macros assuming +one single user value. +Note, however, that userdata with zero user values +are more efficient memory-wise. +

    • + +
    • +The function lua_resume has an extra parameter. +This out parameter returns the number of values on +the top of the stack that were yielded or returned by the coroutine. +(In previous versions, +those values were the entire stack.)
    • -Function lua_dump has an extra parameter, strip. -Use 0 as the value of this parameter to get the old behavior. +The function lua_version returns the version number, +instead of an address of the version number. +The Lua core should work correctly with libraries using their +own static copies of the same core, +so there is no need to check whether they are using the same +address space.
    • -Functions to inject/project unsigned integers -(lua_pushunsigned, lua_tounsigned, lua_tounsignedx, -luaL_checkunsigned, luaL_optunsigned) -were deprecated. -Use their signed equivalents with a type cast. +The constant LUA_ERRGCMM was removed. +Errors in finalizers are never propagated; +instead, they generate a warning.
    • -Macros to project non-default integer types -(luaL_checkint, luaL_optint, luaL_checklong, luaL_optlong) -were deprecated. -Use their equivalent over lua_Integer with a type cast -(or, when possible, use lua_Integer in your code). +The options LUA_GCSETPAUSE and LUA_GCSETSTEPMUL +of the function lua_gc are deprecated. +You should use the new option LUA_GCINC to set them.
    @@ -10917,7 +11887,11 @@ and LiteralString, see §3.1.) for namelist in explist do block end | function funcname funcbody | local function Name funcbody | - local namelist [‘=’ explist] + local attnamelist [‘=’ explist] + + attnamelist ::= Name attrib {‘,’ Name attrib} + + attrib ::= [‘<’ Name ‘>’] retstat ::= return [explist] [‘;’] @@ -10975,10 +11949,10 @@ and LiteralString, see §3.1.) diff --git a/3rdparty/lua/doc/readme.html b/3rdparty/lua/doc/readme.html index 96a9386e2af..8afe38de923 100644 --- a/3rdparty/lua/doc/readme.html +++ b/3rdparty/lua/doc/readme.html @@ -1,7 +1,7 @@ -Lua 5.3 readme +Lua 5.4 readme