Mercurial > vba-linux

     1 /*

     2 ** $Id: ltm.c,v 2.8.1.1 2007/12/27 13:02:25 roberto Exp $

     3 ** Tag methods

     4 ** See Copyright Notice in lua.h

     5 */

     6 

     7 

     8 #include <string.h>

     9 

    10 #define ltm_c

    11 #define LUA_CORE

    12 

    13 #include "lua.h"

    14 

    15 #include "lobject.h"

    16 #include "lstate.h"

    17 #include "lstring.h"

    18 #include "ltable.h"

    19 #include "ltm.h"

    20 

    21 

    22 

    23 const char *const luaT_typenames[] = {

    24   "nil", "boolean", "userdata", "number",

    25   "string", "table", "function", "userdata", "thread",

    26   "proto", "upval"

    27 };

    28 

    29 

    30 void luaT_init (lua_State *L) {

    31   static const char *const luaT_eventname[] = {  /* ORDER TM */

    32     "__index", "__newindex",

    33     "__gc", "__mode", "__eq",

    34     "__add", "__sub", "__mul", "__div", "__mod",

    35     "__pow", "__unm", "__len", "__lt", "__le",

    36     "__concat", "__call"

    37   };

    38   int i;

    39   for (i=0; i<TM_N; i++) {

    40     G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);

    41     luaS_fix(G(L)->tmname[i]);  /* never collect these names */

    42   }

    43 }

    44 

    45 

    46 /*

    47 ** function to be used with macro "fasttm": optimized for absence of

    48 ** tag methods

    49 */

    50 const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {

    51   const TValue *tm = luaH_getstr(events, ename);

    52   lua_assert(event <= TM_EQ);

    53   if (ttisnil(tm)) {  /* no tag method? */

    54     events->flags |= cast_byte(1u<<event);  /* cache this fact */

    55     return NULL;

    56   }

    57   else return tm;

    58 }

    59 

    60 

    61 const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {

    62   Table *mt;

    63   switch (ttype(o)) {

    64     case LUA_TTABLE:

    65       mt = hvalue(o)->metatable;

    66       break;

    67     case LUA_TUSERDATA:

    68       mt = uvalue(o)->metatable;

    69       break;

    70     default:

    71       mt = G(L)->mt[ttype(o)];

    72   }

    73   return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject);

    74 }

    75
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 03 Mar 2012 10:31:27 -0600
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