Platform independent approach to Unicode literals in Lua.

• Enables use of Unicode characters in Lua identifiers (variable and function names)
• Needs recompilation of Lua (configuration change in luaconf.h

Situation without this change:

• *NIX users can simply use setlocale to set the locale to a UTF-8 locale and it will work. (If no UTF-8 locale is available, it won't work.)
• Windows does not support UTF-8 locales and then there is the overhead of using UCS-2 (char -> wchar_t). Additionally big parts of Lua would have to be changed to use TCHAR and the associated functions.
• Lua users in general can use the table syntax _G["some utf8 characters"] (it would work but this is cumbersome)

Add this to the section Local configuration (luaconf.h):

#ifdef LUA_CORE
// all utf-8 chars are always alphabetic character (everything higher then
// 2^7 is always a valid char), end of stream (-1) is not valid
#define isalpha(zeich) (((0x80&zeich)||isalpha(zeich))&&zeich!=-1)
// all utf-8 chars are always alphabetic character or numbers, end of
// stream (-1) is not valid
#define isalnum(zeich) (((0x80&zeich)||isalnum(zeich))&&zeich!=-1)
// all utf-8 chars are never numbers, end of stream (-1) is not valid
#define isdigit(zeich) ((!(0x80&zeich)&&isdigit(zeich))&&zeich!=-1)
// all utf-8 chars are never whitespace characters, end of stream (-1) is
// not valid
#define isspace(zeich) ((!(0x80&zeich)&&isspace(zeich))&&zeich!=-1)
#endif

Please note that all Unicode characters will be allowed. (this is maybe a problem, because some characters look similar to Lua keywords, operators and whitespace.)

Then recompile Lua and try these samples:

local function Gr邢e(message)
 print(message)
end
Gr邢eAusDeutschland = "Hallo Welt 糜邢"
 -- As you see we are using a global variable with UTF-8 characters
Gr邢e(Gr邢eAusDeutschland) -- call to local function with UTF-8 characters
-- Please add other Language samples here ;)
-- Just to prove my point some google translate gibberish:
日本からのご挨拶 = "ハローワールド" -- japanese
Gr邢e(日本からのご挨拶)

HendrikPolczynski 2009年11月20日 - First Revision

For Unicode String support and validation please see:

• ValidateUnicodeString
• slnunicode on LuaForge

For general information about Unicode in Lua see:

• LuaUnicode

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Last edited February 21, 2018 11:49 pm GMT (diff)