Global variables

lglobal.c

@@ -0,0 +1,71 @@
+/*
+** $Id: $
+** Global variables
+** See Copyright Notice in lua.h
+*/
+
+#include <stdlib.h>
+
+#include "lbuiltin.h"
+#include "lglobal.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstring.h"
+
+
+Symbol *luaG_global = NULL;
+int luaG_nglobal = 0;
+static int maxglobal = 0;
+
+
+
+Word luaG_findsymbol (TaggedString *t)
+{
+  if (maxglobal == 0) {  /* first time? */
+    maxglobal = 50;
+    luaG_global = luaM_newvector(maxglobal, Symbol);
+    luaB_predefine();
+  }
+  if (t->u.s.varindex == NOT_USED) {
+    if (!t->marked) t->marked = 2;  /* avoid GC of global variable names */
+    if (luaG_nglobal >= maxglobal)
+      maxglobal = luaM_growvector(&luaG_global, maxglobal, Symbol,
+                             symbolEM, MAX_WORD);
+    t->u.s.varindex = luaG_nglobal;
+    luaG_global[luaG_nglobal].varname = t;
+    s_ttype(luaG_nglobal) = LUA_T_NIL;
+    luaG_nglobal++;
+  }
+  return t->u.s.varindex;
+}
+
+
+Word luaG_findsymbolbyname (char *name)
+{
+  return luaG_findsymbol(luaS_new(name));
+}
+
+
+int luaG_globaldefined (char *name)
+{
+  return s_ttype(luaG_findsymbolbyname(name)) != LUA_T_NIL;
+}
+
+
+int luaG_nextvar (Word next)
+{
+  while (next < luaG_nglobal && s_ttype(next) == LUA_T_NIL)
+    next++;
+  return (next < luaG_nglobal ? next : -1);
+}
+
+
+char *luaG_travsymbol (int (*fn)(TObject *))
+{
+  int i;
+  for (i=0; i<luaG_nglobal; i++)
+    if (fn(&s_object(i)))
+      return luaG_global[i].varname->str;
+  return NULL;
+}
+