+
−/*
+
−** $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"
+
−
+
−
+
−
+
−const char *const luaT_typenames[] = {
+
−  "nil", "boolean", "userdata", "number",
+
−  "string", "table", "function", "userdata", "thread",
+
−  "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"
+
−  };
+
−  int i;
+
−  for (i=0; i<TM_N; i++) {
+
−    G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
+
−    luaS_fix(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? */
+
−    events->flags |= cast_byte(1u<<event);  /* 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:
+
−      mt = hvalue(o)->metatable;
+
−      break;
+
−    case LUA_TUSERDATA:
+
−      mt = uvalue(o)->metatable;
+
−      break;
+
−    default:
+
−      mt = G(L)->mt[ttype(o)];
+
−  }
+
−  return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject);
+
−}
+
−