diff -r 1645f6cc9667 -r 50cb2b90daa9 lemon/bits/item_writer.h
--- a/lemon/bits/item_writer.h	Tue Oct 17 11:05:23 2006 +0000
+++ b/lemon/bits/item_writer.h	Wed Oct 18 15:05:12 2006 +0000
@@ -24,6 +24,7 @@
 #define LEMON_BITS_ITEM_WRITER_H
 
 #include <iostream>
+#include <sstream>
 #include <string>
 
 #include <vector>
@@ -39,10 +40,101 @@
   /// \ingroup item_io
   /// \brief Writer class for quoted strings.
   ///
+  /// Writer class for unformatted strings.
+  /// \author Balazs Dezso
+  class UnformattedWriter {
+  public:
+    typedef std::string Value;
+
+    /// \brief Constructor for the writer.
+    ///
+    /// Constructor for the writer.
+    UnformattedWriter() {}
+
+    /// \brief Writes an unformatted string to the given stream.
+    ///
+    /// Writes an unformatted string to the given stream.
+    void write(std::ostream& os, const std::string& value) const {
+      os << value;
+    }
+
+    bool readable(const std::string& value) const {
+      std::istringstream is(value);
+      char c;
+      while (is.get(c) && !whiteSpace(c)) {
+        if (!processChar(c, is)) return false;
+      }
+      if (is) return false;
+      return true;
+    }
+
+  private:
+
+    bool processChar(char c, std::istream& is) const {
+      switch (c) {
+      case '(':
+        is.putback(c);
+        if (!readableParsed('(', ')', is)) return false;
+        break;
+      case '[':
+        is.putback(c);
+        if (!readableParsed('[', ']', is)) return false;
+        break;
+      case '{':
+        is.putback(c);
+        if (!readableParsed('{', '}', is)) return false;
+        break;
+      case '\"':
+        is.putback(c);
+        if (!readableQuoted('\"', is)) return false;
+        break;
+      case '\'':
+        is.putback(c);
+        if (!readableQuoted('\'', is)) return false;
+        break;
+      default:
+        break;
+      }
+      return true;
+    }
+
+    bool readableParsed(char open, char close, std::istream& is) const {
+      char c;
+      if (!is.get(c) || c != open) return false;
+      while (is.get(c) && c != close) {
+        if (!processChar(c, is)) return false;
+      }
+      if (!is) return false;
+      return true;
+    }
+
+    bool readableQuoted(char quote, std::istream& is) const {
+      char c;
+      bool esc = false;
+      if (!is.get(c) || c != quote) return false;
+      while (is.get(c) && c != quote && !esc) {
+        if (c == '\\') esc = !esc;
+        else esc = false;
+      }
+      if (!is) return false;
+      return true;
+    }
+
+    static bool whiteSpace(char c) {
+      return c == ' ' || c == '\t' || c == '\v' || 
+        c == '\n' || c == '\r' || c == '\f'; 
+    }
+
+  };
+
+  /// \ingroup item_io
+  /// \brief Writer class for quoted strings.
+  ///
   /// Writer class for quoted strings. It can process the escape
   /// sequences in the string.
   /// \author Balazs Dezso
   class QuotedStringWriter {
+    friend class QuotedCharWriter;
   public:
     typedef std::string Value;
 
@@ -120,6 +212,41 @@
   };
 
   /// \ingroup item_io
+  /// \brief Writer class for quoted chars.
+  ///
+  /// Writer class for quoted char. It can process the escape
+  /// sequences in the string.
+  /// \author Balazs Dezso
+  class QuotedCharWriter {
+  public:
+    typedef char Value;
+
+    /// \brief Constructor for the writer.
+    ///
+    /// Constructor for the writer. If the given parameter is true
+    /// the writer creates escape sequences from special characters.
+    QuotedCharWriter(bool _escaped = true) : escaped(_escaped) {}
+
+    /// \brief Writes a quoted char to the given stream.
+    ///
+    /// Writes a quoted char to the given stream.
+    void write(std::ostream& os, const char& value) const {
+      os << "\'";
+      if (escaped) {
+	std::ostringstream ls;
+        QuotedStringWriter::writeEscape(ls, value);
+	os << ls.str();
+      } else {
+	os << value;
+      }
+      os << "\'";
+    }
+
+  private:
+    bool escaped;
+  };
+
+  /// \ingroup item_io
   /// \brief Writer class for quoted char array.
   ///
   /// Writer class for quoted char array. It can process the escape
@@ -258,8 +385,34 @@
   };
 
   template <>
-  class DefaultWriter<std::string> 
-    : public QuotedStringWriter {};
+  class DefaultWriter<std::string> {
+  public:
+    typedef std::string Value;
+    
+    void write(std::ostream& os, const Value& value) const {
+      if (UnformattedWriter().readable(value)) {
+        UnformattedWriter().write(os, value);
+      } else {
+        QuotedStringWriter().write(os, value);
+      }
+    }
+      
+  };
+
+  template <>
+  class DefaultWriter<char> 
+    : public QuotedCharWriter {};
+
+  template <>
+  class DefaultWriter<bool> {
+  public:
+    typedef bool Value;
+    
+    void write(std::ostream& os, const Value& value) const {
+      os << (value ? "1" : "0");
+    }
+      
+  };
 
   template <int length>
   class DefaultWriter<char[length]>