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- Subject: Re: Testing LUA: verify the correctness of a UTF16 LUA port
- From: David Given <dg@...>
- Date: Thu, 15 Oct 2009 05:16:40 +0100
Joshua Jensen wrote:
It does the equivalent of wcscmp(), only it doesn't rely on the C
runtime to achieve this. That's because on some non-Visual C++
compilers, sizeof(wchar_t) != 2. sizeof(lua_WChar) is always 2.
Yes, in the Unix world it's always 4 (wchar_t is an int).
It's easier in the console world --- you've got complete control over
all the text on your system, so you can ensure you're not using any
weird stuff like RTL, surrogates, unsupported combining characters, etc.
I would consider ditching the LuaPlus wide character support if there
was a small library that supported UTF-8 and allowed easy embedding of
UTF-8 string types in Lua source files.
Well, UTF-8 in Lua source files already Just Works. (They're treated by
Lua as Bags of Bytes.) As far as libraries go, I wrote some very simple
UTF-8 parsing code for WordGrinder:
This will let you read and write raw code points from/to a string in a
relatively simple manner.
Thinking about this, a while back I did actually find that Unicode has
real rules for splitting up a UTF-8 string into 'characters', each of
which is an arbitrary-sized string representing a single drawable thing
(I forget the exact term --- grapheme clusters?). So theoretically it
ought to be possible to *truly* do random-access on a string. Maybe I
should revisit this at some point.
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