misc/liblua/ltm.c
changeset 2812 0a24853de796
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/liblua/ltm.c	Mon Feb 15 19:49:20 2010 +0000
@@ -0,0 +1,75 @@
+/*
+** $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);
+}
+