Re: 5.2 refman misstates stack signature of luaL_len?

[Dubiousjim <lists+lua@...>]

On Mon, May 28, 2012 at 08:22:54PM -0300, Roberto Ierusalimschy wrote:
> > Lua 5.2.1 (rc2) is now available at
> > 	http://www.lua.org/work/lua-5.2.1-rc2.tar.gz


Since this doesn't seem to have been caught yet, I'll point it out
again:


On Fri, May 18, 2012 at 03:07:58PM -0400, Dubiousjim wrote:
> The 5.2 reference manual states the stack behavior of luaL_len as [-0, +1, e].
> 
> But judging by lauxlib.c, it looks like it's instead [-0, +0, e].
> 
>     LUALIB_API int luaL_len (lua_State *L, int idx) {
>       int l;
>       int isnum;
>       lua_len(L, idx); /* <---- this pushes an object to stack */
>       l = (int)lua_tointegerx(L, -1, &isnum);
>       if (!isnum)
>         luaL_error(L, "object length is not a number");
>       lua_pop(L, 1);  /* remove object <----- but notice */
>       return l;
>     }

-- 
Jim Pryor
dubiousjim@gmail.com