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- /*
- ** $Id: ltm.c,v 2.8.1.1 2007/12/27 13:02:25 roberto Exp $
- ** Tag methods
- ** See Copyright Notice in lua.h
- */
- #include <string.h>
- #define ltm_c
- #define LUA_CORE
- #include "lua.h"
- #include "lobject.h"
- #include "lstate.h"
- #include "lstring.h"
- #include "ltable.h"
- #include "ltm.h"
- /* These must be correspond to the LUA_T* defines in lua.h */
- const char *const luaT_typenames[] = {
- "nil", "boolean", "lightfunction","number", // base type = 0, 1, 2, 3
- "string", "table", "function", "userdata", "thread", // base type = 4, 5, 6, 7, 8
- "proto", "upval"
- };
- void luaT_init (lua_State *L) {
- static const char *const luaT_eventname[] = { /* ORDER TM */
- "__index", "__newindex",
- "__gc", "__mode", "__eq",
- "__add", "__sub", "__mul", "__div", "__mod",
- "__pow", "__unm", "__len", "__lt", "__le",
- "__concat", "__call",
- "__metatable"
- };
- int i;
- for (i=0; i<TM_N; i++) {
- G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
- stringfix(G(L)->tmname[i]); /* never collect these names */
- }
- }
- /*
- ** function to be used with macro "fasttm": optimized for absence of
- ** tag methods
- */
- const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {
- const TValue *tm = luaH_getstr(events, ename);
- lua_assert(event <= TM_EQ);
- if (ttisnil(tm)) { /* no tag method? */
- if (isrwtable(events)) /* if this a (RW) Table */
- events->flags |= cast_byte(1u<<event); /* then cache this fact */
- return NULL;
- }
- else return tm;
- }
- const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {
- Table *mt;
- switch (ttype(o)) {
- case LUA_TTABLE:
- case LUA_TROTABLE:
- mt = hvalue(o)->metatable;
- break;
- case LUA_TUSERDATA:
- mt = uvalue(o)->metatable;
- break;
- default:
- mt = G(L)->mt[ttnov(o)];
- }
- return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject);
- }
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