From: handa <handa>
Date: Fri, 11 Sep 2009 13:11:31 +0000 (+0000)
Subject: *** empty log message ***
X-Git-Url: http://git.chise.org/gitweb/?a=commitdiff_plain;h=c647f605517330db26cbabb4da77f152974feef8;p=m17n%2Fm17n-lib-cs.git

*** empty log message ***
---

diff --git a/XmlExpr.cs b/XmlExpr.cs
index d37fc40..bfd48e7 100644
--- a/XmlExpr.cs
+++ b/XmlExpr.cs
@@ -8,23 +8,23 @@ namespace System.Xml.Expression
 {
   public class Xex
   {
-    public class Name : IEquatable<Name>
+    public struct Name
     {
       private static NameTable nt = new NameTable ();
 
-      private object name;
+      private string name;
 
-      private Name (string str)
+      public Name (string str)
 	{
 	  name = nt.Add (str);
 	}
 
-      private Name (XmlAttribute attr)
+      public Name (XmlAttribute attr)
 	{
-	  name = attr.Value;
+	  name = nt.Add (attr.Value);
 	}
 
-      private Name (XmlNode node)
+      public Name (XmlNode node)
 	{
 	  name = node.Name;
 	}
@@ -34,82 +34,313 @@ namespace System.Xml.Expression
 	return new Name (str);
       }
 
+      public static implicit operator Name (XmlAttribute attr)
+      {
+	return new Name (attr);
+      }
+
+      public static implicit operator Name (XmlNode node)
+      {
+	return new Name (node);
+      }
+
       public static implicit operator string (Name name)
       {
-	return (string) name.name;
+	return name.name;
       }
 
       public static bool operator== (Name n1, Name n2)
 	{
-	  return n1.name == n2.name;
+	  return (object) n1.name == (object) n2.name;
+	}
+
+      public static bool operator== (Name n1, string n2)
+	{
+	  return (object) n1.name == (object) n2;
+	}
+
+      public static bool operator== (string n1, Name n2)
+	{
+	  return (object) n1 == (object) n2.name;
 	}
 
       public static bool operator!= (Name n1, Name n2)
 	{
-	  return n1.name != n2.name;
+	  return (object) n1.name != (object) n2.name;
+	}
+
+      public static bool operator!= (Name n1, string n2)
+	{
+	  return (object) n1.name != (object) n2;
 	}
 
-      public bool Equals (Name other) { return name == other.name; }
-      public override bool Equals (object obj) { return obj == name; }
+      public static bool operator!= (string n1, Name n2)
+	{
+	  return (object) n1 != (object) n2.name;
+	}
+
+      public override bool Equals (object other)
+      {
+	Console.WriteLine ("Equals (object)");
+	return Object.ReferenceEquals (this, other);
+      }
+
       public override int GetHashCode ()
       {
-	return ((string) name).GetHashCode ();
+	return name.GetHashCode ();
       }
 
       public static NameTable Table { get { return nt; } }
     }
 
-    private static Name Nvalue = "value";
-    private static Name Nvar = "var";
-    private static Name Ndefun = "defun";
-    private static Name Ncond = "cond";
+    private static Name Ninteger = "integer";
+    private static Name Nstring = "string";
+    private static Name Nboolean = "boolean";
+    private static Name Nsymbol = "symbol";
+    private static Name Nlist = "list";
+    private static Name Nobject = "object";
+
+    private static Name Nconst = "const";
+    private static Name Nvariable = "varialbe";
+
+    private static Name Nfuncall = "funcall";
+    private static Name Nmname = "mname";
     private static Name Nprogn = "progn";
-    private static Name Nwhen = "when";
 
-    public class Bindings
+    internal class Function
     {
-      private Name name;
-      private object value;
-      private Bindings next;
-	
-      internal Bindings (Name name, object value)
+      internal class Lambda
+      {
+	internal Name[] args;
+	internal Xex[] body;
+
+	public Lambda (XmlNode node, Domain domain)
+	{
+	  Set (node, domain);
+	}
+
+	public void Set (XmlNode node, Domain domain)
+	{
+	  XmlNodeList body = node.ChildNodes;
+	  int idx = 0;
+
+	  if (body[0].Name == "args")
+	    {
+	      XmlNodeList args = body[0].ChildNodes;
+	      if (this.args == null)
+		this.args = new Name[args.Count];
+	      for (int i = 0; i < args.Count; i++)
+		this.args[i] = args[i].InnerText;
+	      idx++;
+	    }
+	  else if (this.args == null)
+	    this.args = new Name[0];
+	  if (this.body == null)
+	    this.body = new Xex[body.Count - idx];
+	  for (int i = 0; idx < body.Count; i++, idx++)
+	    this.body[i] = new Xex (body[idx], domain);
+	}
+      }
+
+      public readonly Name name;
+      public Builtin builtin;
+      public int min_arg, max_arg;
+      internal Lambda lambda;
+      public bool specialp = false;
+
+      public Function (Name name, Builtin builtin,
+		       int min_arg, int max_arg, bool specialp)
       {
 	this.name = name;
-	this.value = value;
+	this.builtin = builtin;
+	this.min_arg = min_arg;
+	this.max_arg = max_arg;
+	this.specialp = specialp;
       }
-	
-      internal Bindings ()
+
+      internal Function (Name name, XmlNode node, Domain domain)
       {
+	this.name = name;
+	lambda = new Lambda (node, domain);
+	this.min_arg = this.max_arg = lambda.args.Length;
       }
-	
-      internal Bindings Bind (Name name, object value)
+
+      private Function ()
+      {
+	name = "nil";
+      }
+
+      public object Call (Xex[] args, Domain domain)
+      {
+	Bindings current = domain.bindings;
+	object result = false;
+
+	try {
+	  if (! specialp)
+	    foreach (Xex e in args)
+	      e.Eval (domain);
+	  if (builtin != null)
+	    return builtin (args, domain);
+	  if (lambda == null)
+	    return null;
+
+	  foreach (Xex e in lambda.body)
+	    result = e.Eval (domain);
+	} finally {
+	  domain.UnboundTo (current);
+	}
+	return result;
+      }
+    }
+
+    internal abstract class Variable
+    {
+      public readonly Name name;
+      public readonly Name type;
+      internal object val;
+
+      public Variable (Name name, Name type, object value)
+      {
+	this.name = name;
+	this.type = type;
+	val = value;
+      }
+
+      public object Value
+      {
+	get { return val; }
+	set
+	  {
+	    if (! ValueP (value))
+	      throw new Exception ("Invalid value type: " + value);
+	    val = value;
+	  }
+      }
+
+      public abstract bool ValueP (object value);
+
+      public override string ToString () { return name + "(" + type + ")"; }
+    }
+
+    internal class VarInt : Variable
+    {
+      public struct Range
       {
-	Bindings bindings = new Bindings (name, value);
-	bindings.next = this;
-	return bindings;
+	public int from, to;
       }
 
-      internal Bindings SetBoundary ()
+      public Range[] ranges;
+
+      public VarInt (Name name, int value) : base (name, Ninteger, value) { }
+
+      public override bool ValueP (object value)
       {
-	Bindings bindings = new Bindings ();
-	bindings.next = this;
-	return this;
+	int i;
+
+	if (! (value is int))
+	  return false;
+	if (ranges == null)
+	  return true;
+	i = (int) value;
+	foreach (Range r in ranges)
+	  if (i >= r.from && i <= r.to)
+	    return true;
+	return false;
       }
+    }
+
+    internal class VarStr : Variable
+    {
+      public string[] ranges;
+
+      public VarStr (Name name, string value) : base (name, Nstring, value) { }
 
-      internal Bindings Pop ()
+      public override bool ValueP (object value)
       {
-	return bindings.next;
+	string str;
+
+	if (! (value is string))
+	  return false;
+	if (ranges == null)
+	  return true;
+	str = (string) value;
+	foreach (string s in ranges)
+	  if (s == str)
+	    return true;
+	return false;
+      }
+    }
+
+    internal class VarBool : Variable
+    {
+      public VarBool (Name name, bool value) : base (name, Nboolean, value) { }
+
+      public override bool ValueP (object value)
+      {
+	return value is bool;
+      }
+    }
+
+    internal class VarMisc : Variable
+    {
+      public VarMisc (Name name, object value) : base (name, Nobject, value) { }
+
+      public override bool ValueP (object value)
+      {
+	return true;
+      }
+    }
+
+    internal class Bindings
+    {
+      private Variable vari;
+      private object old_value;
+      private Bindings next;
+	
+      private Bindings (Variable vari, object value)
+      {
+	this.vari = vari;
+	old_value = value;
+      }
+	
+      public static Bindings Bind (Bindings bindings,
+				   Variable vari, object value)
+      {
+	Bindings b = new Bindings (vari, vari.val);
+
+	b.vari.Value = value;
+	b.next = bindings;
+	return b;
+      }
+
+      internal Bindings UnboundTo (Bindings boundary)
+      {
+	for (Bindings b = this; b != boundary; b = b.next)
+	  vari.val = b.old_value;
+	return boundary;
       }
 
       public override string ToString ()
       {
 	string str = "(bindings";
 	for (Bindings b = this; b != null; b = b.next)
-	  str += " " + name + ":" + value;
+	  str += " " + vari;
 	return str + ")";
       }
     }
 
+    internal class ThrowException : Exception
+    {
+      Name tag;
+      public object value;
+
+      public ThrowException (Name tag, object value) : base ()
+	{
+	  this.tag = tag;
+	  this.value = value;
+	}
+    }
+
     public class Domain
     {
       private Domain parent;
@@ -117,7 +348,9 @@ namespace System.Xml.Expression
 
       internal Dictionary<Name, Function> functions
 	= new Dictionary<Name, Function> ();
-      private Bindings bindings;
+      internal Dictionary<Name, Variable> variables
+	= new Dictionary<Name, Variable> ();
+      internal Bindings bindings;
 
       internal Domain () { }
 
@@ -129,24 +362,14 @@ namespace System.Xml.Expression
 	this.context = context;
       }
 
-      public void Bind (Name name, object value)
+      internal void Bind (Variable vari, object value)
       {
-	if (bindings == null)
-	  bindings = new Bindings (name, value);
-	else
-	  bindings = bindings.Bind (name, value);
+	bindings = Bindings.Bind (bindings, vari, value);
       }
 
-      public Bindings SetBoundary ()
+      internal void UnboundTo (Bindings boundary)
       {
-	boundaries.Push (bindings);
-	return bindings;
-      }
-
-      public void UnboundTo (Bindings boundary)
-      {
-	while (boundary != boundaries.Pop ());
-	while (bindings.Pop != boundary);
+	bindings = bindings.UnboundTo (boundary);
       }
 
       public void Defun (Name name, Builtin builtin, int min_arg, int max_arg)
@@ -189,22 +412,22 @@ namespace System.Xml.Expression
 
 	    if (func.min_arg < nargs || func.max_arg > nargs)
 	      throw new Exception ("Incompatible argument numbers to override: "
-				   + sym);
+				   + name);
 	    func.lambda.Set (node, this);
 	    func.builtin = null;
 	  }
 	else
 	  {
-	    func = new Function (sym, node, this);
-	    functions = functions.Cons (sym, func);
+	    func = new Function (name, node, this);
+	    functions[name] = func;
 	  }	    
       }
 
       internal Function GetFunc (Name name)
       {
-	Function func = (Function) functions.Get (name);
+	Function func;
 
-	if (func == null)
+	if (! functions.TryGetValue (name, out func))
 	  {
 	    if (parent != null)
 	      return parent.GetFunc (name);
@@ -215,49 +438,32 @@ namespace System.Xml.Expression
 
       public bool CopyFunc (Domain domain, Name name)
       {
-	Function func = (Function) functions.Get (name);
-	if (func == null)
-	  return false;
-	domain.functions = domain.functions.Cons (name, func);
+	Function func = GetFunc (name);
+
+	domain.functions[name] = func;
 	return true;
       }
 
       public void CopyFunc (Domain domain)
       {
-	foreach (MPlist p in functions)
-	  domain.functions = domain.functions.Cons (p.key, p.val);
-      }
-
-      public object GetValue (Name name)
-      {
-	MPlist slot = bindings.Find (name);
-
-	if (slot == null)
-	  {
-	    if (parent != null)
-	      return parent.GetValue (name);
-	    throw new Exception ("Unbound variable: " + name);
-	  }
-	return slot.val;
+	foreach (KeyValuePair<Name, Function> kv in functions)
+	  domain.functions[kv.Key] = kv.Value;
       }
 
-      public object SetValue (Name name, object val)
+      internal Variable GetVar (Name name)
       {
-	MPlist boundary = boundaries.Peek ();
+	Variable vari;
 
-	for (MPlist plist = bindings; plist != boundary; plist = plist.next)
-	  if (plist.key == name)
-	    {
-	      plist.val = val;
-	      return val;
-	    }
-	bindings = bindings.Cons (name, val);
-	return val;
+	if (! variables.TryGetValue (name, out vari))
+	  variables[name] = vari = new VarMisc (name, null);
+	return vari;
       }
 
-      public bool IsBound (Name name)
+      internal Variable GetVar (Xex e)
       {
-	return (bindings.Find (name) != null);
+	if (! (e.val is Name))
+	  throw new Exception ("Not a symbol" + e.val);
+	return GetVar ((Name) e.val);
       }
 
       public override string ToString ()
@@ -265,7 +471,10 @@ namespace System.Xml.Expression
 	string str = "<(functions";
 	foreach (KeyValuePair<Name, Function> kv in functions)
 	  str += " " + kv.Key;
-	str += ") " + bindings;
+	str += ") (variabls";
+	foreach (KeyValuePair<Name, Variable> kv in variables)
+	  str += " " + kv.Key;
+	str += " " + bindings;
 	if (context != null)
 	  str += " (" + context + ")";
 	str += ">";
@@ -275,185 +484,97 @@ namespace System.Xml.Expression
 
     public delegate object Builtin (Xex[] args, Domain domain);
 
-    internal class Function
-    {
-      internal class Lambda
-      {
-	internal Name[] args;
-	internal Xex[] body;
-
-	public Lambda (XmlNode node, Domain domain)
-	{
-	  Set (node, domain);
-	}
-
-	public void Set (XmlNode node, Domain domain)
-	{
-	  XmlNodeList body = node.ChildNodes;
-	  int idx = 0;
-
-	  if (body[0].Name == "args")
-	    {
-	      XmlNodeList args = body[0].ChildNodes;
-	      if (this.args == null)
-		this.args = new Name[args.Count];
-	      for (int i = 0; i < args.Count; i++)
-		this.args[i] = args[i].InnerText;
-	      idx++;
-	    }
-	  else if (this.args == null)
-	    this.args = new Name[0];
-	  if (this.body == null)
-	    this.body = new Xex[body.Count - idx];
-	  for (int i = 0; idx < body.Count; i++, idx++)
-	    this.body[i] = new Xex (body[idx], domain);
-	}
-      }
-
-      public readonly Name Name;
-      public Builtin builtin;
-      public int min_arg, max_arg;
-      internal Lambda lambda;
-      public bool specialp = false;
+    private static Domain basic = new Domain ();
 
-      internal static Function ignore, varref, block;
-
-      public Function (Name name, Builtin builtin,
-		       int min_arg, int max_arg, bool specialp)
-      {
-	Name = name;
-	this.builtin = builtin;
-	this.min_arg = min_arg;
-	this.max_arg = max_arg;
-	this.specialp = specialp;
-      }
-
-      internal Function (Name name, XmlNode node, Domain domain)
-      {
-	Name = name;
-	lambda = new Lambda (node, domain);
-	this.min_arg = this.max_arg = lambda.args.Length;
-      }
-
-      private Function ()
-      {
-	Name = Name.nil;
-      }
-
-      static Function ()
-      {
-	ignore = new Function ();
-	varref = new Function (Mvarref, get_value, 1, 1, true);
-	block = new Function (Mprogn, progn, 0, -1, true);
-      }
-
-      private static object get_value (Xex[] args, Domain domain)
-      {
-	return domain.GetValue ((Name) args[0].val);
-      }
-
-      public object Call (Xex[] args, Domain domain)
-      {
-	if (builtin != null)
-	  {
-	    if (! specialp)
-	      foreach (Xex e in args)
-		e.Eval (domain);
-	    return builtin (args, domain);
-	  }
-	if (lambda == null)
-	  return null;
-	Bindings orig_bindings = domain.bindings;
-	object result = false;
-	try {
-	  int i = 0;
-	  foreach (Name arg in lambda.args)
-	    domain.Bind (arg, args[i++].Eval (domain));
-	  foreach (Xex e in lambda.body)
-	    result = e.Eval (domain);
-	} finally {
-	  domain.bindings = orig_bindings;
-	}
-	return result;
-      }
-    }
-
-    private static Domain basic;
+    internal static Function Fprogn;
 
     static Xex ()
     {
-      basic = new Domain ();
-
-      basic.Defun ("set", set_value, 2, 2, true);
-      basic.Defun ("=", set_value, 2, 2, true);
+      basic.Defun ("set", set_value, 2, 2, false);
+      basic.Defun ("=", set_value, 2, 2, false);
+      basic.Defun ("and", and, 1, -1, false);
+      basic.Defun ("&&", and, 1, -1, false);
+      basic.Defun ("or", or, 1, -1, false);
+      basic.Defun ("||", or, 1, -1, false);
+      basic.Defun ("not", not, 1, 1, false);
       basic.Defun ("!", not, 1, 1, false);
-      basic.Defun ("+", plus, 2, -1, false);
-      basic.Defun ("*", multi, 2, -1, false);
-      basic.Defun ("-", minus, 1, -1, false);
-      basic.Defun ("/", divide, 2, -1, false);
-      basic.Defun ("%", percent, 2, -1, false);
+      basic.Defun ("+", add, 2, -1, false);
+      basic.Defun ("*", mul, 2, -1, false);
+      basic.Defun ("-", sub, 1, -1, false);
+      basic.Defun ("/", div, 2, -1, false);
+      basic.Defun ("%", mod, 2, 2, false);
       basic.Defun ("|", logior, 2, -1, false);
       basic.Defun ("&", logand, 2, -1, false);
-      basic.Defun ("+=", pluseq, 2, -1, true);
-      basic.Defun ("*=", multieq, 2, -1, true);
-      basic.Defun ("-=", minuseq, 2, -1, true);
-      basic.Defun ("/=", divideeq, 2, -1, true);
-      basic.Defun ("%=", percenteq, 2, -1, true);
-      basic.Defun ("|=", logioreq, 2, -1, true);
-      basic.Defun ("&=", logandeq, 2, -1, true);
-      basic.Defun ("<<", lshift, 2, 2, false);
-      basic.Defun (">>", rshift, 2, 2, false);
-      basic.Defun ("<<=", lshifteq, 2, 2, true);
-      basic.Defun (">>=", rshifteq, 2, 2, true);
+      basic.Defun ("+=", add_set, 2, -1, true);
+      basic.Defun ("*=", mul_set, 2, -1, true);
+      basic.Defun ("-=", sub_set, 2, -1, true);
+      basic.Defun ("/=", div_set, 2, -1, true);
+      basic.Defun ("%=", mod_set, 2, 2, true);
+      basic.Defun ("|=", logior_set, 2, -1, true);
+      basic.Defun ("&=", logand_set, 2, -1, true);
+      basic.Defun ("<<", lsh, 2, 2, false);
+      basic.Defun (">>", rsh, 2, 2, false);
+      basic.Defun ("<<=", lsh_set, 2, 2, true);
+      basic.Defun (">>=", rsh_set, 2, 2, true);
       basic.Defun ("==", eq, 2, -1, false);
       basic.Defun ("!=", noteq, 2, 2, false);
-      basic.Defun ("<", less, 2, -1, false);
-      basic.Defun ("<=", lesseq, 2, -1, false);
-      basic.Defun (">", more, 2, -1, false);
-      basic.Defun (">=", moreeq, 2, -1, false);
-      basic.Defun ("progn", progn, 0, -1, true);
-      basic.Defun ("if", ifclause, 2, -1, true);
-      basic.Defun ("when", whenclause, 1, -1, true);
-      basic.Defun ("while", whileclause, 1, -1, true);
-
-      basic.AddTranslator (new Translator (translate_cond));
+      basic.Defun ("<", less_than, 2, -1, false);
+      basic.Defun ("<=", less_eq, 2, -1, false);
+      basic.Defun (">", greater_than, 2, -1, false);
+      basic.Defun (">=", greater_eq, 2, -1, false);
+      basic.Defun ("progn", progn_clause, 0, -1, true);
+      basic.Defun ("if", if_clause, 2, -1, true);
+      basic.Defun ("when", when_clause, 1, -1, true);
+      basic.Defun ("while", while_clause, 1, -1, true);
+
+      Fprogn = basic.GetFunc (Nprogn);
+    }
+
+    private static bool is_true (object val)
+    {
+      return (val is bool ? (bool) val
+	      : val is int ? (int) val == 0
+	      : true);
     }
 
     private static object set_value (Xex[] args, Domain domain)
     {
-      return domain.SetValue ((Name) args[0].args[0].val,
-			      args[1].Eval (domain));
+      Variable vari = domain.GetVar (args[0]);
+
+      vari.Value = args[1].val;
+      return vari.val;
     }
 
-    private static object not (Xex[] args, Domain domain)
+    private static object and (Xex[] args, Domain domain)
     {
-      if (args[0].val is int)
-	return (int) args[0].val == 0;
-      if (args[0].val is bool)
-	return ! ((bool) args[0].val);
+      foreach (Xex arg in args)
+	if (! is_true (arg.val))
+	  return false;
       return true;
     }
 
-    private static object plus (Xex[] args, Domain domain)
+    private static object or (Xex[] args, Domain domain)
     {
-      if (args[0].val is int)
-	{
-	  int n = 0;
-	  foreach (Xex e in args)
-	    n += (int) e.val;
-	  return n;
-	}
-      else if (args[0].val is MText)
-	{
-	  MText mt = new MText ();
-	  foreach (Xex e in args)
-	    mt += (MText) e.val;
-	  return mt;
-	}
-      throw new Exception ("Not an integer nor MText: " + args[0].val);
+      foreach (Xex arg in args)
+	if (is_true (arg.val))
+	  return true;
+      return false;
+    }
+
+    private static object not (Xex[] args, Domain domain)
+    {
+      return ! is_true (args[0].val);
     }
 
-      private static object multi (Xex[] args, Domain domain)
+    private static object add (Xex[] args, Domain domain)
+    {
+      int n = 0;
+      foreach (Xex e in args)
+	n += (int) e.val;
+      return n;
+    }
+
+      private static object mul (Xex[] args, Domain domain)
       {
 	int n = 1;
 	foreach (Xex e in args)
@@ -461,7 +582,7 @@ namespace System.Xml.Expression
 	return n;
       }
 
-      private static object minus (Xex[] args, Domain domain)
+      private static object sub (Xex[] args, Domain domain)
       {
 	int n = (int) args[0].val;
 	if (args.Length == 1)
@@ -471,7 +592,7 @@ namespace System.Xml.Expression
 	return n;
       }
 
-      private static object divide (Xex[] args, Domain domain)
+      private static object div (Xex[] args, Domain domain)
       {
 	int n = (int) args[0].val;
 	for (int i = 1; i < args.Length; i++)
@@ -479,12 +600,9 @@ namespace System.Xml.Expression
 	return n;
       }
 
-      private static object percent (Xex[] args, Domain domain)
+      private static object mod (Xex[] args, Domain domain)
       {
-	int n = (int) args[0].val;
-	for (int i = 1; i < args.Length; i++)
-	  n %= (int) args[i].val;
-	return n;
+	return ((int) args[0].val % (int) args[1].val);
       }
 
       private static object logior (Xex[] args, Domain domain)
@@ -497,121 +615,117 @@ namespace System.Xml.Expression
 
       private static object logand (Xex[] args, Domain domain)
       {
-	int n = 0;
-	foreach (Xex e in args)
-	  n &= (int) e.val;
+	int n = (int) args[0].val;
+	for (int i = 1; i < args.Length; i++)
+	  n &= (int) args[i].val;
 	return n;
       }
 
-      private static object pluseq (Xex[] args, Domain domain)
+      private static object add_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	object val = domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
-	if (val is int)
-	  {
-	    int n = (int) val;
-	    for (int i = 1; i < args.Length; i++)
-	      n += (int) args[i].Eval (domain);
-	    val = n;
-	  }
-	else if (val is MText)
-	  {
-	    MText mt = (MText) val;
-	    for (int i = 1; i < args.Length; i++)
-	      mt.Cat ((MText) args[i].Eval (domain));
-	    val = mt;
-	  }
-	domain.SetValue (sym, val);
-	return val;
+	for (int i = 1; i < args.Length; i++)
+	  n += (int) args[i].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object multieq (Xex[] args, Domain domain)
+      private static object mul_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
 	for (int i = 1; i < args.Length; i++)
-	  n *= (int) args[i].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	  n *= (int) args[i].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object minuseq (Xex[] args, Domain domain)
+      private static object sub_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
 	for (int i = 1; i < args.Length; i++)
-	  n -= (int) args[i].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	  n -= (int) args[i].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object divideeq (Xex[] args, Domain domain)
+      private static object div_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
 	for (int i = 1; i < args.Length; i++)
-	  n /= (int) args[i].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	  n /= (int) args[i].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object percenteq (Xex[] args, Domain domain)
+      private static object mod_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
 	for (int i = 1; i < args.Length; i++)
-	  n %= (int) args[i].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	  n %= (int) args[i].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object logioreq (Xex[] args, Domain domain)
+      private static object logior_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
 	for (int i = 1; i < args.Length; i++)
-	  n |= (int) args[i].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	  n |= (int) args[i].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object logandeq (Xex[] args, Domain domain)
+      private static object logand_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
 	for (int i = 1; i < args.Length; i++)
-	  n &= (int) args[i].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	  n &= (int) args[i].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object lshift (Xex[] args, Domain domain)
+      private static object lsh (Xex[] args, Domain domain)
       {
 	return (int) args[0].val << (int) args[1].val;
       }
 
-      private static object lshifteq (Xex[] args, Domain domain)
+      private static object lsh_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
-	n <<= (int) args[1].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	n <<= (int) args[1].val;
+	vari.val = n;
+	return n;
       }
 
-      private static object rshift (Xex[] args, Domain domain)
+      private static object rsh (Xex[] args, Domain domain)
       {
 	return (int) args[0].val >> (int) args[1].val;
       }
 
-      private static object rshifteq (Xex[] args, Domain domain)
+      private static object rsh_set (Xex[] args, Domain domain)
       {
-	Name sym = (Name) args[0].args[0].val;
-	int n = (int) domain.GetValue (sym);
+	Variable vari = domain.GetVar (args[0]);
+	int n = (int) vari.val;
 
-	n >>= (int) args[1].Eval (domain);
-	return domain.SetValue (sym, (object) n);
+	n >>= (int) args[1].val;
+	vari.val = n;
+	return n;
       }
 
       private static object eq (Xex[] args, Domain domain)
@@ -629,7 +743,7 @@ namespace System.Xml.Expression
 	return ((int) args[0].val != (int) args[1].val);
       }
 
-      private static object less (Xex[] args, Domain domain)
+      private static object less_than (Xex[] args, Domain domain)
       {
 	int n = (int) args[0].val;
 
@@ -643,7 +757,7 @@ namespace System.Xml.Expression
 	return true;
       }
 
-      private static object lesseq (Xex[] args, Domain domain)
+      private static object less_eq (Xex[] args, Domain domain)
       {
 	int n = (int) args[0].val;
 	for (int i = 1; i < args.Length; i++)
@@ -656,7 +770,7 @@ namespace System.Xml.Expression
 	return true;
       }
 
-      private static object more (Xex[] args, Domain domain)
+      private static object greater_than (Xex[] args, Domain domain)
       {
 	int n = (int) args[0].val;
 	for (int i = 1; i < args.Length; i++)
@@ -669,7 +783,7 @@ namespace System.Xml.Expression
 	return true;
       }
 
-      private static object moreeq (Xex[] args, Domain domain)
+      private static object greater_eq (Xex[] args, Domain domain)
       {
 	int n = (int) args[0].val;
 	for (int i = 1; i < args.Length; i++)
@@ -682,48 +796,44 @@ namespace System.Xml.Expression
 	return true;
       }
 
-      private static object progn (Xex[] args, Domain domain)
+      private static object progn_clause (Xex[] args, Domain domain)
       {
-	object result = false;
+	object result = true;
 
 	foreach (Xex e in args)
 	  result = e.Eval (domain);
 	return result;
       }
 
-      private static bool check_condition (Xex condition, Domain domain)
+      private static object if_clause (Xex[] args, Domain domain)
       {
-	object result = condition.Eval (domain);
-	return (result is bool ? (bool) result
-		: result is int ? ((int) result) != 0
-		: true);
-      }
-
-      private static object ifclause (Xex[] args, Domain domain)
-      {
-	object result = false;
+	object result;
 
-	if (check_condition (args[0], domain))
+	if (is_true (args[0].Eval (domain)))
 	  result = args[1].Eval (domain);
 	else
-	  for (int i = 2; i < args.Length; i++)
-	    result = args[i].Eval (domain);
+	  {
+	    result = false;
+	    for (int i = 2; i < args.Length; i++)
+	      result = args[i].Eval (domain);
+	  }
 	return result;
       }
 
-      private static object whenclause (Xex[] args, Domain domain)
+      private static object when_clause (Xex[] args, Domain domain)
       {
-	object result = false;
+	if (! is_true (args[0].Eval (domain)))
+	  return false;
 
-	if (check_condition (args[0], domain))
-	  for (int i = 1; i < args.Length; i++)
-	    result = args[i].Eval (domain);
+	object result = true;
+	for (int i = 1; i < args.Length; i++)
+	  result = args[i].Eval (domain);
 	return result;
       }
 
-      private static object whileclause (Xex[] args, Domain domain)
+      private static object while_clause (Xex[] args, Domain domain)
       {
-	while (check_condition (args[0], domain))
+	while (is_true (args[0].Eval (domain)))
 	  for (int i = 1; i < args.Length; i++)
 	    args[i].Eval (domain);
 	return false;
@@ -740,21 +850,53 @@ namespace System.Xml.Expression
     public Xex[] Args { get { return args; } }
     public object Val { get { return val; } }
 
+    private Xex () { }
+
     private Xex (object val)
     {
       this.val = val;
     }
 
+    private static Xex macro_expand (Xex[] bindings, Name[] args, Xex e)
+    {
+      Xex xex;
+
+      if (e.function != null)
+	{
+	  xex = new Xex ();
+	  xex.function = e.function;
+	  xex.args = new Xex[e.args.Length];
+	  for (int i = e.args.Length - 1; i >= 0; i--)
+	    xex.args[i] = macro_expand (bindings, args, e.args[i]);
+	}
+      else if (e.args != null)
+	{
+	  xex = new Xex ();
+	  Name name = (Name) e.args[0].val;
+	  for (int i = args.Length - 1; i >= 0; i--)
+	    if (args[i] == name)
+	      return bindings[i];
+	  xex.function = null;
+	  xex.args = new Xex[1];
+	  xex.args[0] = e.args[0];
+	}
+      else
+	{
+	  xex = e;
+	}
+      return xex;
+    }
+
     // EXPR = SYMBOL | MTEXT | INTEGER | FUNCALL | PROGN
     // FUNCALL = '(' SYMBOL EXPR* ')'
     // PROGN = '(' EXPR * ')'
-    private Xex (XmlNode node, Domain domain)
+    public Xex (XmlNode node, Domain domain)
     {
-      object name = node.Name;
+      Name name = node.Name;
 
-      if (name == Nvalue)
+      if (name == Nconst)
 	{
-	  object type = node.Attributes["type"];
+	  Name type = node.Attributes["type"].Value;
 
 	  if (type == Ninteger)
 	    val = parse_integer (node.InnerText);
@@ -766,7 +908,7 @@ namespace System.Xml.Expression
 	    val = node.InnerText == "true";
 	  else if (type == Nlist)
 	    {
-	      List<Xex> list = new List<Xex>;
+	      List<Xex> list = new List<Xex> ();
 	      for (XmlNode n = node.FirstChild; n != null; n = n.NextSibling)
 		list.Add (new Xex (n, domain));
 	      val = list;
@@ -774,91 +916,106 @@ namespace System.Xml.Expression
 	  else
 	    throw new Exception ("Unknown type: " + type);
 	}
-      else if (name = Nval)
+      else if (name == Nvariable)
 	{
-	  name = name.Attributes[];
-
 	  args = new Xex[1];
-	  args[0] = new Xex (
-
-
+	  args[0] = new Xex (node.Attributes[0]);
 	}
-      else if (key == Name.plist)
+      else
 	{
-	  MPlist p = (MPlist) val;
+	  bool is_macro = false;
 
-	  if (p.IsSymbol)
+	  if (name == Nfuncall)
 	    {
-	      Name sym = p.Symbol;
-
-	      if (sym == Mdefun)
-		{
-		  p = p.next;
-		  if (! p.IsSymbol)
-		    throw new Exception ("Invalid function argument: "
-					 + p.val);
-		  sym = p.Symbol;
-		  p = p.next;
-		  if (! p.IsPlist)
-		    throw new Exception ("Invalid function argument: "
-					 + p.val);
-		  domain.Defun (sym, p.Plist, p.next);
-		  // This Xex is just a dummy.
-		}
-	      else
-		{
-		  function = domain.GetFunc (sym);
-		  p = p.next;
-		  int nargs = p.Count;
-		  if (nargs < function.min_arg
-		      || (function.max_arg >= 0 && nargs > function.max_arg))
-		    throw new Exception ("Invalid number of arguments to: "
-					 + sym + " " + nargs);
-		  args = new Xex[nargs];
-		  for (int i = 0; i < nargs; i++, p = p.next)
-		    {
-		      domain.Translate (p);
-		      args[i] = new Xex (p.key, p.val, domain);
-		    }
-		}
+	      name = node.Attributes[0].Value;
+	      if (Nmname == node.Attributes[0].Name)
+		is_macro = true;
 	    }
-	  else
+	  function = domain.GetFunc (name);
+
+	  XmlNodeList nlist = node.ChildNodes;
+	  int nargs = nlist.Count;
+
+	  if (nargs < function.min_arg
+	      || (function.max_arg >= 0 && nargs > function.max_arg))
+	    throw new Exception ("Invalid number of arguments to: "
+				 + name + " " + nargs);
+	  args = new Xex[nargs];
+	  for (int i = 0; i < nargs; i++)
+	    args[i] = new Xex (nlist[i]);
+
+	  if (is_macro)
 	    {
-	      args = new Xex[1];
-	      args[0] = new Xex (p, domain);
+	      Function.Lambda lambda = function.lambda;
+	      Xex[] body = lambda.body;
+	      int len = body.Length;
+	      Xex[] newargs = new Xex[len];
+
+	      for (int i = 0; i < len; i++)
+		newargs[i] = macro_expand (args, lambda.args, body[i]);
+	      function = Fprogn;
+	      args = newargs;
 	    }
 	}
-      else
-	throw new Exception ("Invalid expression: " + key + ":" + val);
     }
 
-    public Xex (XmlNode node, Domain domain)
+    private int parse_integer (string str)
     {
-      Name sym = node.Name;
-
-      function = domain.GetFunc (sym);
+      int len = str.Length;
+      bool negative = false;
 
-      XmlAttributeCollection attrs = node.Attributes;
+      if (len <= 1)
+	return (len == 0 ? 0 : str[0]);
 
-      int nargs = attrs.Count + node.ChildNodes.Count;
-      if (nargs < function.min_arg
-	  || (function.max_arg >= 0 && nargs > function.max_arg))
-	throw new Exception ("Invalid number of arguments: " + node.InnerXml);
-      args = new Xex[nargs];
+      int c = str[0];
       int i;
-      for (i = 0; i < attrs.Count; i++)
-	{
-	  string str = attrs[i].Value;
 
+      if (c == '0' && str[1] == 'x')
+	{
+	  i = 0;
+	  for (int idx = 2; idx < len; idx++)
+	    {
+	      c = str[idx];
+	      if (c < '0')
+		break;
+	      else if (c <= '9')
+		i = i * 16 + c;
+	      else if (c < 'A')
+		break;
+	      else if (c <= 'F')
+		i = i * 16 + (c - 'A');
+	      else if (c < 'a')
+		break;
+	      else if (c <= 'f')
+		i = i * 16 + (c - 'a');
+	      else
+		break;
+	    }
+	  return i;
+	}
+      if (c == '-')
+	negative = true;
+      i = c;
+      for (int idx = 1; idx < len; idx++)
+	{
+	  c = str[idx];
+	  if (c < '0' || c > '9')
+	    break;
+	  i = i * 10 + (c - '0');
 	}
+      return negative ? - i : i;
     }
 
     public object Eval (Domain domain)
     {
       if (function == null)
 	{
-	  if (val is Name)
-	    val = domain.GetValue ((Name) val);
+	  if (args != null)
+	    {
+	      Variable vari = domain.GetVar ((Name) args[0].val);
+	      val = vari.val;
+	    }
+	  return val;
 	}
       else
 	val = function.Call (args, domain);
@@ -871,16 +1028,20 @@ namespace System.Xml.Expression
 
       if (function != null)
 	{
-	  str = "(" + function.Name.Name;
+	  str = "(" + function.name;
 	  if (args != null)
 	    foreach (Xex e in args)
 	      str += " " + e.ToString ();
 	  str += ")";
 	}
+      else if (args != null)
+	{
+	  str = (string) args[0].val;
+	}
       else if (val != null)
 	{
-	  if (val is MText)
-	    str = "\"" + (string) ((MText) val) + "\"";
+	  if (val is string)
+	    str = "\"" + ((string) val) + "\"";
 	  else
 	    str = val.ToString ();
 	}