--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dmdscript_tango/symbol.d	Sun Jan 24 12:34:47 2010 +0200
@@ -0,0 +1,200 @@
+
+/* Digital Mars DMDScript source code.
+ * Copyright (c) 2000-2002 by Chromium Communications
+ * D version Copyright (c) 2004-2005 by Digital Mars
+ * All Rights Reserved
+ * written by Walter Bright
+ * www.digitalmars.com
+ * Use at your own risk. There is no warranty, express or implied.
+ * License for redistribution is by the GNU General Public License in gpl.txt.
+ *
+ * A binary, non-exclusive license for commercial use can be
+ * purchased from www.digitalmars.com/dscript/buy.html.
+ *
+ * DMDScript is implemented in the D Programming Language,
+ * www.digitalmars.com/d/
+ *
+ * For a C++ implementation of DMDScript, including COM support,
+ * see www.digitalmars.com/dscript/cppscript.html.
+ */
+
+
+module dmdscript.symbol;
+
+import std.stdio;
+
+import dmdscript.script;
+import dmdscript.identifier;
+import dmdscript.scopex;
+import dmdscript.statement;
+import dmdscript.irstate;
+import dmdscript.opcodes;
+import dmdscript.errmsgs;
+
+/****************************** Symbol ******************************/
+
+class Symbol
+{
+    Identifier *ident;
+
+    this()
+    {
+    }
+
+    this(Identifier *ident)
+    {
+	this.ident = ident;
+    }
+
+    int opEquals(Object o)
+    {   Symbol s;
+
+	if (this == o)
+	    return true;
+	s = cast(Symbol)o;
+	if (s && ident == s.ident)
+	    return true;
+	return false;
+    }
+
+    tchar[] toString()
+    {
+	return ident ? "__ident" : "__anonymous";
+    }
+
+    void semantic(Scope *sc)
+    {
+	assert(0);
+    }
+
+    Symbol search(Identifier *ident)
+    {
+	assert(0);
+	//error(DTEXT("%s.%s is undefined"),toString(), ident.toString());
+	return this;
+    }
+
+    void toBuffer(inout tchar[] buf)
+    {
+	buf ~= toString();
+    }
+}
+
+
+/********************************* ScopeSymbol ****************************/
+
+// Symbol that generates a scope
+
+class ScopeSymbol : Symbol
+{
+    Symbol[] members;		// all Symbol's in this scope
+    SymbolTable *symtab;	// member[] sorted into table
+
+    this()
+    {
+	super();
+    }
+
+    this(Identifier *id)
+    {
+	super(id);
+    }
+
+    Symbol search(Identifier *ident)
+    {   Symbol s;
+
+	//writef("ScopeSymbol::search(%s, '%s')\n", toString(), ident.toString());
+	// Look in symbols declared in this module
+	s = symtab ? symtab.lookup(ident) : null;
+	if (s)
+	    writef("\ts = '%s.%s'\n",toString(),s.toString());
+	return s;
+    }
+}
+
+
+/****************************** SymbolTable ******************************/
+
+// Table of Symbol's
+
+struct SymbolTable
+{
+    Symbol[Identifier*] members;
+
+    // Look up Identifier. Return Symbol if found, NULL if not.
+    Symbol lookup(Identifier *ident)
+    {
+	Symbol *ps;
+
+	ps = ident in members;
+	if (ps)
+	    return *ps;
+	return null;
+    }
+
+    // Insert Symbol in table. Return NULL if already there.
+    Symbol insert(Symbol s)
+    {
+	Symbol *ps;
+
+	ps = s.ident in members;
+	if (ps)
+	    return null;	// already in table
+	members[s.ident] = s;
+	return s;
+    }
+
+    // Look for Symbol in table. If there, return it.
+    // If not, insert s and return that.
+    Symbol update(Symbol s)
+    {
+	members[s.ident] = s;
+	return s;
+    }
+}
+
+
+/****************************** FunctionSymbol ******************************/
+
+class FunctionSymbol : ScopeSymbol
+{
+    Loc loc;
+
+    Identifier*[] parameters;		// array of Identifier's
+    TopStatement[] topstatements;	// array of TopStatement's
+
+    SymbolTable labtab;		// symbol table for LabelSymbol's
+
+    IR *code;
+    uint nlocals;
+
+    this(Loc loc, Identifier* ident, Identifier*[] parameters,
+	TopStatement[] topstatements)
+    {
+	super(ident);
+	this.loc = loc;
+	this.parameters = parameters;
+	this.topstatements = topstatements;
+    }
+
+    void semantic(Scope *sc)
+    {
+    }
+}
+
+
+/****************************** LabelSymbol ******************************/
+
+class LabelSymbol : Symbol
+{   Loc loc;
+    LabelStatement statement;
+
+    this(Loc loc, Identifier* ident, LabelStatement statement)
+    {
+	super(ident);
+	this.loc = loc;
+	this.statement = statement;
+    }
+}
+
+