misc/liblua/ltm.c
author nemo
Fri, 23 Mar 2012 18:20:59 -0400
changeset 6810 5337f554480e
parent 2812 0a24853de796
permissions -rw-r--r--
This has bugged me for a while. Since we are missing the source SVGs for this theme, removed the leaves crudely in GIMP. Also added some basic roots. Someone more artistic is encouraged to try and improve it.

/*
** $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);
}