1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/*
** $Id: ltm.c,v 2.14 2011/06/02 19:31:40 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"
static const char udatatypename[] = "userdata";
LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = {
"no value",
"nil", "boolean", udatatypename, "number",
"string", "table", "function", udatatypename, "thread",
"proto", "upval" /* these last two cases are used for tests only */
};
void luaT_init (lua_State *L) {
static const char *const luaT_eventname[] = { /* ORDER TM */
"__index", "__newindex",
"__gc", "__mode", "__len", "__eq",
"__add", "__sub", "__mul", "__div", "__mod",
"__pow", "__unm", "__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 (ttypenv(o)) {
case LUA_TTABLE:
mt = hvalue(o)->metatable;
break;
case LUA_TUSERDATA:
mt = uvalue(o)->metatable;
break;
default:
mt = G(L)->mt[ttypenv(o)];
}
return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject);
}
|
