lua/ltm.c

68 lines
1.5 KiB
C

/*
** $Id: ltm.c,v 1.1 2001/11/29 22:14:34 rieru Exp rieru $
** Tag methods
** See Copyright Notice in lua.h
*/
#include <stdio.h>
#include <string.h>
#include "lua.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "ltm.h"
const char *const luaT_typenames[] = {
"userdata", "nil", "number", "boolean", "string", "table", "function"
};
void luaT_init (lua_State *L) {
static const char *const luaT_eventname[] = { /* ORDER TM */
"gettable", "settable", "index",
"gc",
"add", "sub", "mul", "div",
"pow", "unm", "lt", "concat",
"call"
};
int i;
for (i=0; i<TM_N; i++) {
G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
G(L)->tmname[i]->tsv.marked = FIXMARK; /* never collect these names */
}
}
/*
** function to be used with macro "fasttm": optimized for absence of
** tag methods
*/
const TObject *luaT_gettm (Table *events, TMS event, TString *ename) {
const TObject *tm = luaH_getstr(events, ename);
if (ttype(tm) == LUA_TNIL) { /* no tag method? */
events->flags |= (1<<event); /* cache this fact */
return NULL;
}
else return tm;
}
const TObject *luaT_gettmbyobj (lua_State *L, const TObject *o, TMS event) {
TString *ename = G(L)->tmname[event];
switch (ttype(o)) {
case LUA_TTABLE:
return luaH_getstr(hvalue(o)->eventtable, ename);
case LUA_TUSERDATA:
return luaH_getstr(uvalue(o)->uv.eventtable, ename);
default:
return &luaO_nilobject;
}
}