Compatibility module providing Lua-5.3-style APIs for Lua 5.2 and 5.1
Lua-5.3-style APIs for Lua 5.2 and 5.1.
This is a small module that aims to make it easier to write code in a Lua-5.3-style that is compatible with Lua 5.1, Lua 5.2, and Lua 5.3. This does not make Lua 5.2 (or even Lua 5.1) entirely compatible with Lua 5.3, but it brings the API closer to that of Lua 5.3.
It includes:
compat53
, which can be require'd
from Lua scripts and run in Lua 5.1, 5.2, and 5.3, including a
backport of the utf8
module, the 5.3 table
module, and the
string packing functions straight from the Lua 5.3 sources.require("compat53")
compat53
makes changes to your global environment and does not return
a meaningful return value, so the usual idiom of storing the return of
require
in a local variable makes no sense.
When run under Lua 5.3+, this module does nothing.
When run under Lua 5.2 or 5.1, it replaces some of your standard
functions and adds new ones to bring your environment closer to that
of Lua 5.3. It also tries to load the backported utf8
, table
, and
string packing modules automatically. If unsuccessful, pure Lua
versions of the new table
functions are used as a fallback, and
Roberto's struct library is tried for string packing.
local _ENV = require("compat53.module")
if setfenv then setfenv(1, _ENV) end
The compat53.module
module does not modify the global environment,
and so it is safe to use in modules without affecting other Lua files.
It is supposed to be set as the current environment (see above), i.e.
cherry picking individual functions from this module is expressly
not supported!). Not all features are available when using this
module (e.g. yieldable (x)pcall support, string/file methods, etc.),
so it is recommended to use plain require("compat53")
whenever
possible.
There are two ways of adding the C API compatibility functions/macros to your project:
COMPAT53_PREFIX
is not #define
d, compat-5.3.h
#include
s
compat-5.3.c
, and all functions are made static
. You don't have to
compile/link/add compat-5.3.c
yourself. This is useful for one-file
projects.COMPAT53_PREFIX
is #define
d, all exported functions are renamed
behind the scenes using this prefix to avoid linker conflicts with other
code using this package. This doesn't change the way you call the
compatibility functions in your code. You have to compile and link
compat-5.3.c
to your project yourself. You can change the way the
functions are exported using the COMPAT53_API
macro (e.g. if you need
some __declspec
magic). While it is technically possible to use
the "lua" prefix (and it looks better in the debugger), this is
discouraged because LuaJIT has started to implement its own Lua 5.2+
C API functions, and with the "lua" prefix you'd violate the
one-definition rule with recent LuaJIT versions.utf8
module backported from the Lua 5.3 sourcesstring.pack
, string.packsize
, and string.unpack
from the Lua
5.3 sources or from the struct
module. (struct
is not 100%
compatible to Lua 5.3's string packing!) (See here)math.maxinteger
and math.mininteger
, math.tointeger
, math.type
,
and math.ult
(see here)assert
accepts non-string error messagesipairs
respects __index
metamethodtable.move
table
library respects metamethodsFor Lua 5.1 additionally:
load
and loadfile
accept mode
and env
parameterstable.pack
and table.unpack
string.rep
accepts sep
argumentstring.format
calls tostring
on arguments for %s
math.log
accepts base argumentxpcall
takes additional argumentspcall
and xpcall
can execute functions that yield (see
here for a possible problem with coroutine.running
)pairs
respects __pairs
metamethod (see here)rawlen
(but #
still doesn't respect __len
for tables)package.searchers
as alias for package.loaders
package.searchpath
(see here)coroutine
functions dealing with the main coroutine (see
here for a possible problem with coroutine.running
)coroutine.create
accepts functions written in Cos.execute
(see here)io.write
and file:write
return file handleio.lines
and file:lines
accept format arguments (like io.read
)
(see here and here)debug.setmetatable
returns objectdebug.getuservalue
(see here)debug.setuservalue
(see here)lua_KContext
(see here)lua_KFunction
(see here)lua_dump
(extra strip
parameter, ignored, see here)lua_getextraspace
(limited compatibilitiy, see here)lua_getfield
(return value)lua_geti
and lua_seti
lua_getglobal
(return value)lua_getmetafield
(return value)lua_gettable
(return value)lua_getuservalue
(limited compatibility, see here)lua_setuservalue
(limited compatibility, see here)lua_isinteger
lua_numbertointeger
lua_callk
and lua_pcallk
(limited compatibility, see here)lua_resume
lua_rawget
and lua_rawgeti
(return values)lua_rawgetp
and lua_rawsetp
luaL_requiref
(now checks package.loaded
first)lua_rotate
lua_stringtonumber
(see here)For Lua 5.1 additionally:
LUA_OK
LUA_ERRGCMM
LUA_OP*
macros for lua_arith
and lua_compare
LUA_FILEHANDLE
lua_Unsigned
luaL_Stream
(limited compatibility, see here)lua_absindex
lua_arith
(see here)lua_compare
lua_len
, lua_rawlen
, and luaL_len
lua_load
(mode argument)lua_pushstring
, lua_pushlstring
(return value)lua_copy
lua_pushglobaltable
luaL_testudata
luaL_setfuncs
, luaL_newlibtable
, and luaL_newlib
luaL_setmetatable
luaL_getsubtable
luaL_traceback
luaL_execresult
luaL_fileresult
luaL_loadbufferx
luaL_loadfilex
luaL_checkversion
(with empty body, only to avoid compile errors,
see here)luaL_tolstring
luaL_buffinitsize
, luaL_prepbuffsize
, and luaL_pushresultsize
(see here)lua_pushunsigned
, lua_tounsignedx
, lua_tounsigned
,
luaL_checkunsigned
, luaL_optunsigned
, if
LUA_COMPAT_APIINTCASTS
is defined.coroutine.isyieldable
_ENV
, goto
, labels, ephemeron tables, etc. See
lua-compat-5.2
for a detailed list.lua_isyieldable
lua_arith
(new operators missing)lua_push(v)fstring
(new formats missing)lua_upvalueid
(5.1)lua_upvaluejoin
(5.1)lua_version
(5.1)lua_yieldk
(5.1)This package contains code written by:
Philipp Janda (@siffiejoe)
Tomás Guisasola Gorham (@tomasguisasola)
Hisham Muhammad (@hishamhm)
Renato Maia (@renatomaia)