tag system replaced by event tables

1 files changed, 24 insertions, 141 deletions

diff --git a/ltm.c b/ltm.c
index ef0f89e1..5d1c83d1 100644
--- a/ltm.c
+++ b/ltm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.c,v 1.80 2001/10/11 21:41:21 roberto Exp $
+** $Id: ltm.c,v 1.1 2001/11/29 22:14:34 rieru Exp rieru $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -10,8 +10,6 @@
 
 #include "lua.h"
 
-#include "ldo.h"
-#include "lmem.h"
 #include "lobject.h"
 #include "lstate.h"
 #include "lstring.h"
@@ -19,161 +17,46 @@
 #include "ltm.h"
 
 
-const char *const luaT_eventname[] = {  /* ORDER TM */
-  "gettable", "settable", "index", "getglobal",
-  "setglobal", "add", "sub", "mul", "div",
-  "pow", "unm", "lt", "concat", "gc",
-  "function",
-  NULL
-};
-
-
-static int findevent (const 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 char *name) {
-  int e = findevent(name);
-  if (e < 0)
-    luaO_verror(L, "`%.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 */
+const char *const luaT_typenames[] = {
+  "userdata", "nil", "number", "string", "table", "function"
 };
 
-static int luaT_validevent (int t, int e) {  /* ORDER LUA_T */
-  return (t >= NUM_TAGS) ?  1 : cast(int, luaT_validevents[t][e]);
-}
-
 
 void luaT_init (lua_State *L) {
-  static const char *const typenames[NUM_TAGS] = {
-    "userdata", "nil", "number", "string",
-    "table", "function"
+  static const char *const luaT_eventname[] = {  /* ORDER TM */
+    "gettable", "settable", "index",
+    "gc",
+    "add", "sub", "mul", "div",
+    "pow", "unm", "lt", "concat",
+    "call"
   };
   int i;
-  for (i=0; i<NUM_TAGS; i++)
-    luaT_newtag(L, typenames[i], i);
-}
-
-
-int luaT_newtag (lua_State *L, const 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, "tag table overflow");
-  tag = G(L)->ntag;
-  if (name) {
-    const TObject *v;
-    TObject otag;
-    ts = luaS_new(L, name);
-    v = luaH_getstr(G(L)->type2tag, ts);
-    if (ttype(v) == LUA_TNUMBER) return cast(int, nvalue(v));
-    setnvalue(&otag, tag);
-    luaH_setstr(L, G(L)->type2tag, ts, &otag);
+  for (i=0; i<TM_N; i++) {
+    G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
+    G(L)->tmname[i]->tsv.marked = FIXMARK;  /* never collect these names */
   }
-  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, "%d is not a valid tag", tag);
 }
 
 
-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 TObject *luaT_gettm (Table *events, TMS event, TString *ename) {
+  const TObject *tm = luaH_getstr(events, ename);
+  if (ttype(tm) == LUA_TNIL) {  /* no tag method? */
+    events->flags |= (1<<event);  /* cache this fact */
+    return NULL;
   }
+  else return tm;
 }
 
 
-const 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;
+const TObject *luaT_gettmbyobj (lua_State *L, const TObject *o, TMS event) {
+  switch (ttype(o)) {
     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 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 char *event) {
-  int e;
-  lua_lock(L);
-  e = luaI_checkevent(L, event);
-  checktag(L, t);
-  if (!luaT_validevent(t, e))
-    luaO_verror(L, "cannot change `%.20s' tag method for type `%.20s'%.20s",
-                luaT_eventname[e], typenamebytag(G(L), t),
-                (t == LUA_TTABLE || t == LUA_TUSERDATA) ?
-                   " with default tag" : "");
-  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;
+      return fasttm(L, hvalue(o)->eventtable, event);
+    case LUA_TUSERDATA:
+      return fasttm(L, uvalue(o)->uv.eventtable, event);
     default:
-      luaD_error(L, "tag method must be a function (or nil)");
+      return NULL;
   }
-  L->top--;
-  lua_unlock(L);
 }