X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=MPlist.cs;h=35cafd8e1f736326fa700e119328b3cc32586368;hb=2d42f6c7d4ea06fec44c84d25097be67a0664318;hp=3c9b140860d8e5bd51759f48ad46e7d66a9f0dc2;hpb=2d755fa02471fd07ce009f9caf5789583a72e7ec;p=m17n%2Fm17n-lib-cs.git

diff --git a/MPlist.cs b/MPlist.cs
index 3c9b140..35cafd8 100644
--- a/MPlist.cs
+++ b/MPlist.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections;
+using System.Collections.Generic;
 using System.IO;
 using M17N;
 using M17N.Core;
@@ -8,25 +9,36 @@ namespace M17N.Core
 {
   public class MPlist : IEnumerable
   {
-    public MSymbol Key;
-    public object Val;
-    private MPlist next;
+    public MSymbol key;
+    public object val;
+    public MPlist next;
+
+    public MSymbol Key { get { return key; } }
+    public object Val { get { return val; } }
+    public MPlist Next { get { return next; } }
+
+    private static List<MSymbol> wf_keys;
+
+    static MPlist ()
+      {
+	wf_keys = new List<MSymbol> ();
+	wf_keys.Add (MSymbol.symbol);
+	wf_keys.Add (MSymbol.mtext);
+	wf_keys.Add (MSymbol.plist);
+	wf_keys.Add (MSymbol.integer);
+      }
 
     public MPlist ()
       {
-	Key = MSymbol.nil;
-	Val = null;
+	key = MSymbol.nil;
+	val = null;
       }
 
     public MPlist (FileStream stream)
       {
 	MStreamReader reader = new MStreamReader (stream);
-	MSymbol key;
-	object val;
 	bool result = reader.ReadElement (out key, out val);
 
-	Key = key;
-	Val = val;
 	if (result)
 	  next = new MPlist (reader);
       }
@@ -34,35 +46,60 @@ namespace M17N.Core
     public MPlist (FileStream stream, int count)
       {
 	MStreamReader reader = new MStreamReader (stream);
-	MSymbol key;
-	object val;
 	bool result = reader.ReadElement (out key, out val);
 
-	Key = key;
-	Val = val;
 	if (result && --count > 0)
 	  next = new MPlist (reader, count);
 	else
 	  next = new MPlist ();
       }
 
+    public MPlist (FileStream stream, MSymbol stop)
+      {
+	MStreamReader reader = new MStreamReader (stream);
+	bool result;
+
+	key = MSymbol.nil;
+	val = null;
+	while (true)
+	  {
+	    MSymbol this_key;
+	    object this_val;
+
+	    result = reader.ReadElement (out this_key, out this_val);
+	    if (! result)
+	      return;
+	    if (this_key == MSymbol.plist)
+	      {
+		MPlist plist = (MPlist) this_val;
+
+		if (plist.IsSymbol && plist.Symbol == stop)
+		  return;
+	      }
+	    key = this_key;
+	    val = this_val;
+	    next = new MPlist (reader, stop);
+	  }
+      }
+
     public MPlist (FileStream stream, MSymbol target, MSymbol stop)
       {
 	MStreamReader reader = new MStreamReader (stream);
-	MSymbol key;
-	object val;
 	bool result;
 
-	Key = MSymbol.nil;
-	Val = null;
+	key = MSymbol.nil;
+	val = null;
 	while (true)
 	  {
-	    result = reader.ReadElement (out key, out val);
+	    MSymbol this_key;
+	    object this_val;
+
+	    result = reader.ReadElement (out this_key, out this_val);
 	    if (! result)
 	      return;
-	    if (key == MSymbol.plist)
+	    if (this_key == MSymbol.plist)
 	      {
-		MPlist plist = (MPlist) val;
+		MPlist plist = (MPlist) this_val;
 
 		if (plist.IsSymbol)
 		  {
@@ -70,8 +107,8 @@ namespace M17N.Core
 		      return;
 		    if (plist.Symbol == target)
 		      {
-			Key = target;
-			Val = val;
+			key = target;
+			val = this_val;
 			next = new MPlist ();
 			return;
 		      }
@@ -80,48 +117,79 @@ namespace M17N.Core
 	  }
       }
 
-    private MPlist (MStreamReader reader)
+    internal MPlist (MStreamReader reader)
       {
-	MSymbol key;
-	object val;
 	bool result = reader.ReadElement (out key, out val);
 
-	Key = key;
-	Val = val;
 	if (result)
 	  next = new MPlist (reader);
       }
 
     private MPlist (MStreamReader reader, int count)
       {
-	MSymbol key;
-	object val;
 	bool result = reader.ReadElement (out key, out val);
 
-	Key = key;
-	Val = val;
 	if (result && --count > 0)
 	  next = new MPlist (reader, count);
 	else
 	  next = new MPlist ();
       }
 
+    private MPlist (MStreamReader reader, MSymbol stop)
+      {
+	bool result;
+	MPlist next_plist = null;
+
+	key = MSymbol.nil;
+	val = null;
+	while (true)
+	  {
+	    MSymbol this_key;
+	    object this_val;
+
+	    result = reader.ReadElement (out this_key, out this_val);
+	    if (! result)
+	      return;
+	    if (this_key == MSymbol.plist)
+	      {
+		MPlist plist = (MPlist) this_val;
+
+		if (plist.IsSymbol && plist.Symbol == stop)
+		  return;
+	      }
+	    if (next_plist == null)
+	      {
+		key = this_key;
+		val = this_val;
+		next = next_plist = new MPlist ();
+	      }
+	    else
+	      {
+		next_plist.key = this_key;
+		next_plist.val = this_val;
+		next_plist.next = new MPlist ();
+		next_plist = next_plist.next;
+	      }
+	  }
+      }
+
     private MPlist (MStreamReader reader, MSymbol target, MSymbol stop)
       {
-	MSymbol key;
-	object val;
 	bool result;
 
-	Key = MSymbol.nil;
-	Val = null;
+	key = MSymbol.nil;
+	val = null;
 	while (true)
 	  {
-	    result = reader.ReadElement (out key, out val);
+	    MSymbol this_key;
+	    object this_val;
+
+	    result = reader.ReadElement (out this_key, out this_val);
 	    if (! result)
 	      return;
-	    if (key == MSymbol.plist)
+	    if (this_key == MSymbol.plist)
 	      {
-		MPlist plist = (MPlist) val;
+		MPlist plist = (MPlist) this_val;
 
 		if (plist.IsSymbol)
 		  {
@@ -129,8 +197,8 @@ namespace M17N.Core
 		      return;
 		    if (plist.Symbol == target)
 		      {
-			Key = target;
-			Val = val;
+			key = target;
+			val = this_val;
 			next = new MPlist ();
 			return;
 		      }
@@ -139,24 +207,23 @@ namespace M17N.Core
 	  }
       }
 
-    private MPlist (MSymbol key, object val)
+    protected MPlist (MSymbol key, object val)
       {
-	Key = key;
-	Val = val;
+	this.key = key;
+	this.val = val;
       }
 
     public bool IsEmpty { get { return next == null; } }
-    public MPlist Next { get { return next; } }
 
-    internal bool IsSymbol { get { return Key == MSymbol.symbol; } }
-    internal bool IsMText { get { return Key == MSymbol.mtext; } }
-    internal bool IsPlist { get { return Key == MSymbol.plist; } }
-    internal bool IsInteger { get { return Key == MSymbol.integer; } }
+    public bool IsSymbol { get { return Key == MSymbol.symbol; } }
+    public bool IsMText { get { return Key == MSymbol.mtext; } }
+    public bool IsPlist { get { return Key == MSymbol.plist; } }
+    public bool IsInteger { get { return Key == MSymbol.integer; } }
 
-    internal MSymbol Symbol { get { return (MSymbol) Val; } }
-    internal MText Text { get { return (MText) Val; } }
-    internal MPlist Plist { get { return (MPlist) Val; } }
-    internal int Integer { get { return (int) Val; } }
+    public MSymbol Symbol { get { return (MSymbol) val; } }
+    public MText Text { get { return (MText) val; } }
+    public MPlist Plist { get { return (MPlist) val; } }
+    public int Integer { get { return (int) val; } }
 
     public int Count
     {
@@ -169,12 +236,21 @@ namespace M17N.Core
 	}
     }
 
+    public MPlist this[int i]
+    {
+      get {
+	MPlist p;
+	for (p = this; ! p.IsEmpty && i > 0; i--, p = p.next);
+	return (i == 0 ? p : null);
+      }
+    }
+
     public MPlist Clone ()
     {
       MPlist plist = new MPlist (), pl = plist;
 
       for (MPlist p = this; p.next != null; p = p.next)
-	pl = pl.Add (p.Key, p.Val);
+	pl = pl.Add (p.key, p.val);
       return plist;
     }
 
@@ -186,15 +262,12 @@ namespace M17N.Core
 	  {
 	    if (p != this)
 	      str += " ";
-	    if (p.Key != MSymbol.symbol
-		&& p.Key != MSymbol.integer
-		&& p.Key != MSymbol.plist
-		&& p.Key != MSymbol.mtext)
-	      str += p.Key + ":";
-	    if (p.Key == MSymbol.mtext)
-	      str += "\"" + p.Val + "\"";
+	    if (! wf_keys.Contains (p.key))
+	      str += p.key + ":";
+	    if (p.key == MSymbol.mtext)
+	      str += "\"" + p.val + "\"";
 	    else
-	      str += p.Val;
+	      str += p.val;
 	  }
 	return str + ")";
     }
@@ -204,7 +277,7 @@ namespace M17N.Core
       MPlist p;
 
       for (p = this; ! p.IsEmpty; p = p.next)
-	if (p.Key == key)
+	if (p.key == key)
 	  break;
       return p;
     }
@@ -218,7 +291,7 @@ namespace M17N.Core
 
     public object Get (MSymbol key)
     {
-      return find (key).Val;
+      return find (key).val;
     }
 
     internal MPlist Assq (MSymbol key)
@@ -251,7 +324,7 @@ namespace M17N.Core
       if (IsEmpty)
 	Push (key, val);
       else
-	Val = val;
+	this.val = val;
       return this;
     }
 
@@ -272,11 +345,11 @@ namespace M17N.Core
 
     public MPlist Push (MSymbol key, object val)
     {
-      MPlist p = new MPlist (Key, Val);
+      MPlist p = new MPlist (this.key, this.val);
 
       p.next = this.next;
-      Key = key;
-      Val = val;
+      this.key = key;
+      this.val = val;
       next = p;
       return this;
     }
@@ -288,22 +361,22 @@ namespace M17N.Core
 
     public object Pop (out MSymbol key)
     {
-      key = Key;
+      key = this.key;
       if (IsEmpty)
 	return null;
 
-      object val = Val;
+      object this_val = val;
 
-      Key = next.Key;
-      Val = next.Val;
+      this.key = next.key;
+      this.val = next.val;
       next = next.next;
-      return val;
+      return this_val;
     }
 
     public object Pop ()
     {
-      MSymbol key;
-      return Pop (out key);
+      MSymbol temp;
+      return Pop (out temp);
     }
 
     public MPlist Add (MSymbol key, object val)
@@ -314,10 +387,19 @@ namespace M17N.Core
       return p.Push (key, val);
     }
 
+    public MPlist Cons (MSymbol key, object val)
+    {
+      MPlist plist = new MPlist ();
+      plist.key = key;
+      plist.val = val;
+      plist.next = this;
+      return plist;
+    }
+
     public MPlist Clear ()
     {
-      Key = MSymbol.nil;
-      Val = null;
+      key = MSymbol.nil;
+      val = null;
       next = null;
       return this;
     }
@@ -363,220 +445,331 @@ namespace M17N.Core
 	return (! current.IsEmpty);
       }
     }
+  }
 
-    private class MStreamReader : StreamReader
-    {
-      private static char[] escaped_char = new char[128];
-      private static int[] hexadecimal = new int[128];
-
-      public MStreamReader (Stream stream) : base (stream)
-	{
-	}
-
-      static MStreamReader ()
-	{
-	  for (int i = 0; i < 128; i++)
-	    escaped_char[i] = (char) i;
-	  escaped_char['e'] = (char) 27;
-	  escaped_char['b'] = '\b';
-	  escaped_char['f'] = '\f';
-	  escaped_char['n'] = '\n';
-	  escaped_char['r'] = '\r';
-	  escaped_char['t'] = '\t';
-	  escaped_char['\\'] = '\\';
-	  for (int i = 0; i < 128; i++)
-	    hexadecimal[i] = -1;
-	  for (int i = '0'; i <= '9'; i++)
-	    hexadecimal[i] = i - '0';
-	  for (int i = 'A'; i <= 'F'; i++)
-	    hexadecimal[i] = hexadecimal[i + 'a' - 'A'] = i -'A' + 10;
-	}
+  public class MStreamReader : StreamReader
+  {
+    private static char[] escaped_char = new char[128];
+    private static int[] hexadecimal = new int[128];
+    private char comment_start;
+    private bool line_oriented;
 
-      private int PeekChar ()
+    public MStreamReader (Stream stream) : base (stream)
       {
-	bool comment = false;
-	int c;
-
-	while ((c = Peek ()) != -1)
-	  {
-	    if (comment)
-	      {
-		if ((c = Read ()) == '\n')
-		  comment = false;
-	      }
-	    else
-	      {
-		if (c == ';')
-		  comment = true;
-		else if (c != ' ' && c != '\t' && c != '\n')
-		  return c;
-		Read ();
-	      }
-	  }
-	return c;
+	comment_start = ';';
+	line_oriented = false;
       }
 
-      private int ReadHexadecimal ()
+    public MStreamReader (Stream stream, char comment_start,
+			  bool line_oriented) : base (stream)
       {
-	int i = 0, c;
-
-	while ((c = Peek ()) >= 0 && c < 128 && (c = hexadecimal[c]) >= 0)
-	  {
-	    Read ();
-	    i = (i * 16) + c;
-	  }
-	return i;
+	this.comment_start = comment_start;
+	this.line_oriented = line_oriented;
       }
 
-      private int ReadInteger ()
+    static MStreamReader ()
       {
-	int i = 0, c;
-
-	while ((c = Peek ()) >= '0' && c <= '9')
-	  i = (i * 10) + (Read () - '0');
-	return i;
+	for (int i = 0; i < 128; i++)
+	  escaped_char[i] = (char) i;
+	escaped_char['0'] = (char) 0;
+	escaped_char['e'] = (char) 27;
+	escaped_char['a'] = '\a';
+	escaped_char['b'] = '\b';
+	escaped_char['f'] = '\f';
+	escaped_char['n'] = '\n';
+	escaped_char['r'] = '\r';
+	escaped_char['t'] = '\t';
+	escaped_char['v'] = '\v';
+	for (int i = 0; i < 128; i++)
+	  hexadecimal[i] = -1;
+	for (int i = '0'; i <= '9'; i++)
+	  hexadecimal[i] = i - '0';
+	for (int i = 'A'; i <= 'F'; i++)
+	  hexadecimal[i] = hexadecimal[i + 'a' - 'A'] = i -'A' + 10;
       }
 
-      private int ReadChar ()
-      {
-	int c = Read ();
+    private int ReadHexadecimal (int max)
+    {
+      int i = 0, c;
 
-	if (c == '\\')
-	  {
-	    c = Read ();
-	    if (c == -1)
-	      return -1;
-	    if (c == 'x' || c == 'u')
-	      return ReadHexadecimal ();
-	    if (c < 128)
-	      c = escaped_char[c];
-	  }
-	return c;
-      }
+      while ((c = Peek ()) >= 0 && c < 128 && (c = hexadecimal[c]) >= 0)
+	{
+	  if (max >= 0 && (i * 16) + c >= max)
+	    break;
+	  Read ();
+	  i = (i * 16) + c;
+	}
+      return i;
+    }
 
-      private MText ReadMtext ()
-      {
-	MText mt = new MText ();
-	int c;
+    public bool ForwardLine ()
+    {
+      int c;
+      while ((c = Read ()) >=0 && c != '\n');
+      return (c == '\n');
+    }
 
-	while ((c = Peek ()) != -1 && c != '"')
-	  {
-	    if (c == '\\')
-	      {
-		c = ReadChar ();
-		if (Peek () == '\n')
-		  {
-		    ReadChar ();
-		    continue;
-		  }
-		if (c == -1)
-		  {
-		    mt.Cat ('\\');
-		    break;
-		  }
-		mt.Cat (c);
-	      }
-	    else
-	      mt.Cat (Read ());
-	  }
-	if (c == '"')
+    public bool SkipSpace (out int c)
+    {
+      while ((c = Peek ()) == ' ' && c == '\t' && c == '\f')
+	Read ();
+      return (c >= 0);
+    }
+
+    public bool PeekChar (out int c)
+    {
+      while ((c = Peek ()) != -1)
+	{
+	  if (c == comment_start)
+	    ForwardLine ();
+	  else if (c != ' ' && c != '\t' && c != '\n')
+	    return true;
+	  else if (c == '\n' && line_oriented)
+	    return false;
+	  else
+	    Read ();
+	}
+      return false;
+    }
+
+    public bool ReadInteger (out int i)
+    {
+      int c = Peek ();
+
+      i = 0;
+      if (c < 0)
+	return false;
+      if (c == '0')
+	{
 	  Read ();
-	return mt;
-      }
+	  c = Peek ();
+	  if (c == 'x')
+	    {
+	      Read ();
+	      i = ReadHexadecimal (-1);
+	      return true;
+	    }
+	}
+      while ((c = Peek ()) >= '0' && c <= '9')
+	i = (i * 10) + (Read () - '0');
+      return true;
+    }
 
-      private string ReadSymbolName ()
-      {
-	int c = Peek ();
+    public bool ReadChar (out int c)
+    {
+      c = Read ();
+      if (c < 0 || (line_oriented && c == '\n'))
+	return false;
+      if (c == '\\')
+	{
+	  c = Read ();
+	  if (c == '\n')
+	    return ReadChar (out c);
+	  if (c < 0)
+	    c = '\\';
+	  else if (c == 'x' || c == 'u' || c == 'U')
+	    c = ReadHexadecimal (0x10FFFF);
+	  else if (c < 128)
+	    c = escaped_char[c];
+	}
+      return true;
+    }
 
-	if (c == -1 || c == '(' || c == ')' || c == ' ' || c == '\n' || c == '"')
-	  return "";
+    private bool read_string (out string str, int prefix, bool for_symbol)
+    {
+      char[] buf = new char[256];
+      int c;
+      int i = 0;
+
+      str = null;
+      if (prefix >= 0)
+	buf[i++] = (char) prefix;
+      while ((c = Peek ()) >= 0
+	     && c != '\"'
+	     && (! for_symbol
+		 || (c != '(' && c != ')' && c != ' ' && c != '\t' && c != '\n')))
+	{
+	  if (! ReadChar (out c))
+	    break;
+	  if (c < 0x10000)
+	    {
+	      buf[i++] = (char) c;
+	    }
+	  else
+	    {
+	      buf[i++] = (char) (0xD800 + ((c - 0x10000) >> 10));
+	      buf[i++] = (char) (0xDC00 + ((c - 0x10000) & 0x3FF));
+	    }
+	  if (i >= 255)
+	    {
+	      if (str == null)
+		str = new string (buf, 0, i);
+	      else
+		str += new string (buf, 0, i);
+	      i = 0;
+	    }
+	}
+      if (c == '\"' && ! for_symbol)
 	Read ();
-	if (c == '\\')
-	  {
-	    c = Read ();
-	    if (c == -1)
-	      c = '\\';
-	  }
-	return (char) c + ReadSymbolName ();
-      }
+      if (i > 0)
+	{
+	  if (str == null)
+	    str = new string (buf, 0, i);
+	  else
+	    str += new string (buf, 0, i);
+	}
+      return (str != null);
+    }
 
-      public bool ReadElement (out MSymbol key, out object val)
-      {
-	int c = PeekChar ();
+    public bool ReadString (out string str)
+    {
+      return read_string (out str, -1, false);
+    }
 
-	if (c == '(')
-	  {
-	    Read ();
-	    val = new MPlist (this);
-	    key = MSymbol.plist;
-	  }
-	else if (c == '"')
-	  {
-	    Read ();
-	    val = ReadMtext ();
-	    key = MSymbol.mtext;
-	  }
-	else if (c >= '0' && c <= '9')
-	  {
-	    int i = ReadInteger ();
+    public bool ReadMText (out MText mt)
+    {
+      int c = Peek ();
 
-	    val = i;
-	    key = MSymbol.integer;
-	  }
-	else if (c == '-')
-	  {
-	    Read ();
-	    c = Peek ();
-	    if (c >= '0' && c <= '9')
-	      {
-		int i = ReadInteger ();
-		val = - i;
-		key = MSymbol.integer;
-	      }
-	    else
-	      {
-		string str = ReadSymbolName ();
+      if (c == '"')
+	{
+	  string str;
 
-		val = MSymbol.Of ("-" + str);
-		key = MSymbol.symbol;
-	      }
-	  }
-	else if (c == '?')
-	  {
-	    Read ();
-	    val = ReadChar ();
-	    key = MSymbol.integer;
-	  }
-	else if (c == '#')
-	  {
-	    Read ();
-	    if ((c = Peek ()) == 'x' || c == 'u')
-	      {
-		Read ();
-		val = ReadHexadecimal ();
-		key = MSymbol.integer;
-	      }
-	    else
-	      {
-		val = MSymbol.Of ("#" + (char) c + ReadSymbolName ());
-		key = MSymbol.symbol;
-	      }
-	  }
-	else if (c == -1 || c == ')')
-	  {
-	    if (c == ')')
+	  Read ();
+	  if (read_string (out str, -1, false))
+	    mt = new MText (str);
+	  else
+	    mt = new MText ();
+	  return true;
+	}
+      mt = new MText ();
+      if (c == '\\')
+	{
+	  while ((c = Peek ()) == '\\')
+	    {
 	      Read ();
-	    val = null;
-	    key = MSymbol.nil;
-	    return false;
-	  }
-	else
-	  {
-	    val = MSymbol.Of (ReadSymbolName ());
-	    key = MSymbol.symbol;
-	  }
-	return true;
-      }
+	      c = Peek ();
+	      if (c != 'x')
+		break;
+	      Read ();
+	      mt.Cat (ReadHexadecimal (0x10FFFF));
+	    }
+	  return true;
+	}
+      return false;
+    }
+
+    public bool ReadSymbol (out MSymbol sym, int prefix)
+    {
+      string str;
+
+      if (read_string (out str, prefix, true))
+	{
+	  sym = MSymbol.Of (str);
+	  return true;
+	}
+      sym = MSymbol.nil;
+      return false;
+    }
+
+    internal bool ReadElement (out MSymbol key, out object val)
+    {
+      int c;
+
+      if (! PeekChar (out c))
+	{
+	  val = null;
+	  key = MSymbol.nil;
+	  return false;
+	}
+
+      if (c == '(')
+	{
+	  Read ();
+	  val = new MPlist (this);
+	  key = MSymbol.plist;
+	}
+      else if (c == '"' || c == '\\')
+	{
+	  MText mt;
+	  ReadMText (out mt);
+	  val = mt;
+	  key = MSymbol.mtext;
+	}
+      else if (c >= '0' && c <= '9')
+	{
+	  int i;
+	  ReadInteger (out i);
+	  val = i;
+	  key = MSymbol.integer;
+	}
+      else if (c == '-')
+	{
+	  Read ();
+	  c = Peek ();
+	  if (c >= '0' && c <= '9')
+	    {
+	      int i;
+	      ReadInteger (out i);
+	      val = - i;
+	      key = MSymbol.integer;
+	    }
+	  else
+	    {
+	      MSymbol sym;
+
+	      ReadSymbol (out sym, '-');
+	      val = sym;
+	      key = MSymbol.symbol;
+	    }
+	}
+      else if (c == '?')
+	{
+	  Read ();
+	  if (ReadChar (out c))
+	    {
+	      val = c;
+	      key = MSymbol.integer;
+	    }
+	  else
+	    {
+	      val = null;
+	      key = MSymbol.nil;
+	    }
+	}
+      else if (c == '#')
+	{
+	  Read ();
+	  if ((c = Peek ()) == 'x' || c == 'u')
+	    {
+	      Read ();
+	      val = ReadHexadecimal (-1);
+	      key = MSymbol.integer;
+	    }
+	  else
+	    {
+	      MSymbol sym;
+
+	      ReadSymbol (out sym, '#');
+	      val = sym;
+	      key = MSymbol.symbol;
+	    }
+	}
+      else if (c == ')')
+	{
+	  Read ();
+	  val = null;
+	  key = MSymbol.nil;
+	  return false;
+	}
+      else
+	{
+	  MSymbol sym;
+
+	  ReadSymbol (out sym, -1);
+	  val = sym;
+	  key = MSymbol.symbol;
+	}
+      return true;
     }
   }
 }