123

CryScriptSystem/LUA/ltm.c

@@ -0,0 +1,192 @@
+/*
+** $Id: ltm.c,v 1.76 2001/07/24 22:39:34 roberto Exp $
+** Tag methods
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stdio.h>
+#include <string.h>
+
+#define LUA_PRIVATE
+#include "lua.h"
+
+#include "ldo.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+
+
+const l_char *const luaT_eventname[] = {  /* ORDER TM */
+  l_s("gettable"), l_s("settable"), l_s("index"), l_s("getglobal"),
+  l_s("setglobal"), l_s("add"), l_s("sub"), l_s("mul"), l_s("div"),
+  l_s("pow"), l_s("unm"), l_s("lt"), l_s("concat"), l_s("gc"),
+  l_s("function"),
+  NULL
+};
+
+
+static int findevent (const l_char *name) {
+  int i;
+  for (i=0; luaT_eventname[i]; i++)
+    if (strcmp(luaT_eventname[i], name) == 0)
+      return i;
+  return -1;  /* name not found */
+}
+
+
+static int luaI_checkevent (lua_State *L, const l_char *name) {
+  int e = findevent(name);
+  if (e < 0)
+    luaO_verror(L, l_s("`%.50s' is not a valid event name"), name);
+  return e;
+}
+
+
+
+/* events in LUA_TNIL are all allowed, since this is used as a
+*  `placeholder' for default fallbacks
+*/
+/* ORDER LUA_T, ORDER TM */
+static const lu_byte luaT_validevents[NUM_TAGS][TM_N] = {
+  {1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1},  /* LUA_TUSERDATA */
+  {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},  /* LUA_TNIL */
+  {1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1},  /* LUA_TNUMBER */
+  {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},  /* LUA_TSTRING */
+  {0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1},  /* LUA_TTABLE */
+  {1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}   /* LUA_TFUNCTION */
+};
+
+int luaT_validevent (int t, int e) {  /* ORDER LUA_T */
+  return (t >= NUM_TAGS) ?  1 : (int)luaT_validevents[t][e];
+}
+
+
+void luaT_init (lua_State *L) {
+  static const l_char *const typenames[NUM_TAGS] = {
+    l_s("userdata"), l_s("nil"), l_s("number"), l_s("string"),
+    l_s("table"), l_s("function")
+  };
+  int i;
+  for (i=0; i<NUM_TAGS; i++)
+    luaT_newtag(L, typenames[i], i);
+}
+
+
+int luaT_newtag (lua_State *L, const l_char *name, int basictype) {
+  int tag;
+  int i;
+  TString *ts = NULL;
+  luaM_growvector(L, G(L)->TMtable, G(L)->ntag, G(L)->sizeTM, struct TM,
+                  MAX_INT, l_s("tag table overflow"));
+  tag = G(L)->ntag;
+  if (name) {
+    TObject *v;
+    ts = luaS_new(L, name);
+    v = luaH_setstr(L, G(L)->type2tag, ts);
+    if (ttype(v) == LUA_TNUMBER) return (int)nvalue(v);
+    setnvalue(v, tag);
+  }
+  for (i=0; i<TM_N; i++)
+    luaT_gettm(G(L), tag, i) = NULL;
+  G(L)->TMtable[tag].collected = NULL;
+  G(L)->TMtable[tag].name = ts;
+  G(L)->TMtable[tag].basictype = basictype;
+  G(L)->ntag++;
+  return tag;
+}
+
+
+static void checktag (lua_State *L, int tag) {
+  if (!(0 <= tag && tag < G(L)->ntag))
+    luaO_verror(L, l_s("%d is not a valid tag"), tag);
+}
+
+
+LUA_API int lua_copytagmethods (lua_State *L, int tagto, int tagfrom) {
+  int e;
+  lua_lock(L);
+  checktag(L, tagto);
+  checktag(L, tagfrom);
+  for (e=0; e<TM_N; e++) {
+    if (luaT_validevent(tagto, e))
+      luaT_gettm(G(L), tagto, e) = luaT_gettm(G(L), tagfrom, e);
+  }
+  lua_unlock(L);
+  return tagto;
+}
+
+
+int luaT_tag (const TObject *o) {
+  int t = ttype(o);
+  switch (t) {
+    case LUA_TUSERDATA: return uvalue(o)->uv.tag;
+    case LUA_TTABLE:    return hvalue(o)->htag;
+    default:            return t;
+  }
+}
+
+
+const l_char *luaT_typename (global_State *G, const TObject *o) {
+  int t = ttype(o);
+  int tag;
+  TString *ts;
+  switch (t) {
+    case LUA_TUSERDATA:
+      tag = uvalue(o)->uv.tag;
+      break;
+    case LUA_TTABLE:
+      tag = hvalue(o)->htag;
+      break;
+    default:
+      tag = t;
+  }
+  ts = G->TMtable[tag].name;
+  if (ts == NULL)
+    ts = G->TMtable[t].name;
+  return getstr(ts);
+}
+
+
+LUA_API void lua_gettagmethod (lua_State *L, int t, const l_char *event) {
+  int e;
+  lua_lock(L);
+  e = luaI_checkevent(L, event);
+  checktag(L, t);
+  if (luaT_validevent(t, e) && luaT_gettm(G(L), t, e)) {
+    setclvalue(L->top, luaT_gettm(G(L), t, e));
+  }
+  else
+    setnilvalue(L->top);
+  incr_top;
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_settagmethod (lua_State *L, int t, const l_char *event) {
+  int e;
+  lua_lock(L);
+  e = luaI_checkevent(L, event);
+  checktag(L, t);
+  if (!luaT_validevent(t, e))
+    luaO_verror(L, l_s("cannot change `%.20s' tag method for type `%.20s'%.20s"),
+                luaT_eventname[e], typenamebytag(G(L), t),
+                (t == LUA_TTABLE || t == LUA_TUSERDATA) ?
+                   l_s(" with default tag") : l_s(""));
+  switch (ttype(L->top - 1)) {
+    case LUA_TNIL:
+      luaT_gettm(G(L), t, e) = NULL;
+      break;
+    case LUA_TFUNCTION:
+      luaT_gettm(G(L), t, e) = clvalue(L->top - 1);
+      break;
+    default:
+      luaD_error(L, l_s("tag method must be a function (or nil)"));
+  }
+  L->top--;
+  lua_unlock(L);
+}
+