Re: Say No to global-by-default (summary of the discussion)
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: Say No to global-by-default (summary of the discussion)
- From: Luiz Henrique de Figueiredo <lhf@...>
- Date: 2018年7月17日 21:55:18 -0300
If you really want to play with this idea, here is a patch for Lua 5.3.5:
diff llex.c noglobal/llex.c
547a548
> #include "proxy.c"
diff lparser.c noglobal/lparser.c
284c284,286
< if (var->k == VVOID) /* not found? */
---
> if (var->k == VVOID) /* not found? */ {
> luaX_syntaxerror(fs->ls,
> luaO_pushfstring(fs->ls->L,"undeclared global " LUA_QL("%s"),getstr(n)));
285a288
> }
% cat test.lua
\a=3
\print(\a)
\print(a)
% cat proxy.c
/*
* proxy.c
* lexer proxy for Lua parser -- implements '\' -> '_ENV.'
* Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br>
* This code is hereby placed in the public domain.
* Add <<#include "proxy.c">> just before the definition of luaX_next in llex.c
*/
static int nexttoken(LexState *ls, SemInfo *seminfo)
{
static int state=0;
int t;
if (state==0) {
t=llex(ls,seminfo);
if (t=='\\') {
state=1;
seminfo->ts=ls->envn;
t=TK_NAME;
}
return t;
} else {
state=0;
return '.';
}
return t;
}
#define llex nexttoken