OLD | NEW |
(Empty) | |
| 1 /* |
| 2 ** $Id: ltm.c,v 2.14 2011/06/02 19:31:40 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 static const char udatatypename[] = "userdata"; |
| 23 |
| 24 LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = { |
| 25 "no value", |
| 26 "nil", "boolean", udatatypename, "number", |
| 27 "string", "table", "function", udatatypename, "thread", |
| 28 "proto", "upval" /* these last two cases are used for tests only */ |
| 29 }; |
| 30 |
| 31 |
| 32 void luaT_init (lua_State *L) { |
| 33 static const char *const luaT_eventname[] = { /* ORDER TM */ |
| 34 "__index", "__newindex", |
| 35 "__gc", "__mode", "__len", "__eq", |
| 36 "__add", "__sub", "__mul", "__div", "__mod", |
| 37 "__pow", "__unm", "__lt", "__le", |
| 38 "__concat", "__call" |
| 39 }; |
| 40 int i; |
| 41 for (i=0; i<TM_N; i++) { |
| 42 G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]); |
| 43 luaS_fix(G(L)->tmname[i]); /* never collect these names */ |
| 44 } |
| 45 } |
| 46 |
| 47 |
| 48 /* |
| 49 ** function to be used with macro "fasttm": optimized for absence of |
| 50 ** tag methods |
| 51 */ |
| 52 const TValue *luaT_gettm (Table *events, TMS event, TString *ename) { |
| 53 const TValue *tm = luaH_getstr(events, ename); |
| 54 lua_assert(event <= TM_EQ); |
| 55 if (ttisnil(tm)) { /* no tag method? */ |
| 56 events->flags |= cast_byte(1u<<event); /* cache this fact */ |
| 57 return NULL; |
| 58 } |
| 59 else return tm; |
| 60 } |
| 61 |
| 62 |
| 63 const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) { |
| 64 Table *mt; |
| 65 switch (ttypenv(o)) { |
| 66 case LUA_TTABLE: |
| 67 mt = hvalue(o)->metatable; |
| 68 break; |
| 69 case LUA_TUSERDATA: |
| 70 mt = uvalue(o)->metatable; |
| 71 break; |
| 72 default: |
| 73 mt = G(L)->mt[ttypenv(o)]; |
| 74 } |
| 75 return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject); |
| 76 } |
| 77 |
OLD | NEW |