source: glemon/xml.h

/* -*- C++ -*-
 *
 * This file is a part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2003-2006
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#ifndef GLEMON_XML_H
#define GLEMON_XML_H

#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <lemon/error.h>
#include <lemon/assert.h>
#include <lemon/dim2.h>

namespace lemon {

  class XmlIo 
  {
    bool _writeMode;
  public:
    ///Check if XmlIo is in write mode.
    bool write() { return _writeMode;}
    ///Check if XmlIo is in read mode.
    bool read() { return !_writeMode;}

    std::ostream& os;
    int level;
    
  protected:
    void indent(int level) {
      os << std::endl;
      for(int i=0;i<level;i++) os << ' ';
    }
    void tag(const std::string &_tag) {
      os << '<' << _tag << '>';
    }
    void etag(const std::string &_tag) {
      os << "</" << _tag << '>';
    }
    void itag(const std::string &_tag) { indent();tag(_tag); }
    void ietag(const std::string &_tag) { indent();etag(_tag); }

    void beginTag(const std::string &_tag) {
      itag(_tag);
      level++;
    }
    void endTag(const std::string &_tag) {
      level--;
      ietag(_tag);
    }

  public:
    ///Indent the line according to its level.

    ///\warning It can only be used in write mode.
    ///
    void indent()
    {
      if(write())
        if(level>=0) indent(level);
        else level=0;
      else LEMON_ASSERT(true, "Invalid indentation.");  
    }
  
    ///Read/write a tag
  
    ///Read/write a tag.
    ///In write mode it does not start a new line.
    class ContTag
    {
      XmlIo &ix;
      const std::string _tag;
    public:
      ///\e
  
      ///\e
      ///
      ContTag(XmlIo &_ix,const std::string &_t) :
        ix(_ix), _tag(_t)
      {
        if(ix.write()) ix.tag(_tag);
        else ix.useTag(_tag);
      }
      ~ContTag() { 
        if(ix.write()) ix.etag(_tag);
        else if(!std::uncaught_exception()) ix.useTag('/'+_tag);      
      }
    };

    ///Read/write a tag
  
    ///Read/write a tag.
    ///The whole \<foo\> ... \</foo\> will be placed in a single line.
    class LineTag
    {
      XmlIo &ix;
      const std::string _tag;
    public:
      ///\e
    
      ///\e
      ///
      LineTag(XmlIo &_ix,const std::string &_t) :
        ix(_ix), _tag(_t)
      {
        if(ix.write()) ix.itag(_tag);
        else ix.useTag(_tag);
      }
      ~LineTag() { 
        if(ix.write()) ix.etag(_tag);
        else if(!std::uncaught_exception()) ix.useTag('/'+_tag);
      }
    };

    ///Read/write a tag
  
    ///Read/write a tag.
    ///
    class Tag
    {
      XmlIo &ix;
      const std::string _tag;
    public:
      ///\e
  
      ///\e
      ///
      Tag(XmlIo &_ix,const std::string &_t) :
        ix(_ix), _tag(_t)
      {
        if(ix.write()) ix.beginTag(_tag);
        else ix.useTag(_tag);
      }
      ~Tag() {
        if(ix.write()) ix.endTag(_tag);
        else if(!std::uncaught_exception()) ix.useTag('/'+_tag);
      }
    };

  private:
    std::istream& is;
    std::string next_tag;
    int line_number;

    void skipWhiteSpaces()
    {
      if(write()) LEMON_ASSERT(true, "Can't skip whitespaces in write mode.");
      {
        char c;
        while (is.get(c) && std::isspace(c,is.getloc()))
          if(c=='\n') line_number++;
        is.unget();
      }
    }
  protected:
    /// Use the next tag.

    ///\e
    ///
    void useTag() {next_tag.clear();}
  
    ///Use the next tag and check if it is equal with \c _tag
  
    ///\e
    ///
    void useTag(const std::string &_tag) {
      if(nextTag()==_tag) useTag();
      else throw FormatError("Unexpected token name","",line_number);
    }
  public:
    ///Return the next tag (if a tag follows on the stream).
  
    ///\warning It can only be used in read mode.
    ///
    const std::string &nextTag() 
    {
      if(write()) LEMON_ASSERT(true,"Don't use nextTag() in write mode");
      else if(next_tag.empty()) {
        char c;
        skipWhiteSpaces();
        if(!is.get(c) || c!='<')
          throw FormatError("Bad format","",line_number);
        next_tag.clear();
        while (is.get(c) && c!='>') next_tag.push_back(c);
        if(c!='>')
          throw FormatError("Bad format","",line_number);
      }
      return next_tag;
    }

    /**********************************************************************/


    ///\e
  
    ///\e
    ///
    XmlIo(std::ostream& _os) : _writeMode(true), os(_os),
                               level(-1),
                               is(std::cin) {}
    ///\e
    ///
    XmlIo(std::istream& _is) : _writeMode(false),
                               os(std::cout), is(_is),
                               line_number(1) {}

    ~XmlIo() { if(write()) os<< std::endl; }
  


    XmlIo &operator()(const int &v) 
    { 
      if(write()) os << v;
      else {
        skipWhiteSpaces();
        if(!(is >> const_cast<int &>(v))) 
          throw FormatError("Not an 'int'","",line_number);
      }
      return *this;
    }
    XmlIo &operator()(const double &v) 
    {
      if(write()) os << v;
      else {
        skipWhiteSpaces();
        if(!(is >> const_cast<double &>(v))) 
          throw FormatError("Not an 'double'","",line_number);
      }
      return *this;
    }
    XmlIo &operator()(const std::string &v)
    {
      if(write())
        for(std::string::const_iterator i=v.begin();i!=v.end();++i)
          switch(*i) {
          case '\\':
            os << "\\\\";
            break;
          case '<':
            os << "\\<";
            break;
          case '&':
            os << "\\&";
            break;
          case '\n':
            os << "\\n";
            break;
          default:
            os<<*i;
            break;
          }
      else {
        std::string &w = const_cast<std::string &>(v);
        w.clear();
        char c;
        while (is.get(c) && c!='<')
          if(c=='\\')
            if(!is.get(c))
              throw FormatError("Bad string","",line_number);
            else switch(c) {
            case 'n':
              w.push_back('\n');
              break;
            default:
              w.push_back(c);
              break;
            }
          else {
            if(c=='\n') line_number++;
            w.push_back(c);
          }
        if(c!='<')
          throw FormatError("Unexpected eof","",line_number);
        is.unget();
      }
      return *this;
    }


    XmlIo &operator()(const std::string &_tag,const int &v) 
    { 
      LineTag t(*this,_tag);
      (*this)(v);
      return *this;
    }
    XmlIo &operator()(const std::string &_tag,const double &v) 
    {
      LineTag t(*this,_tag);
      (*this)(v);
      return *this;
    }
    XmlIo &operator()(const std::string &_tag,const std::string &v)
    {
      LineTag t(*this,_tag);
      (*this)(v);
      return *this;
    }
    ///\e
  
    ///\e
    ///
    template<class V>
    XmlIo &operator()(const std::string &_tag,const V &v)
    {
      Tag t(*this,_tag);
      xml(*this,const_cast<V &>(v));
      return *this;
    }
    ///\e
  
    ///\e
    ///
    template<class V>
    XmlIo &operator()(const V &v)
    {
      xml(*this,const_cast<V &>(v));
      return *this;
    }
    };

  //////////////////////////////////////////////////////////////////////
  //////////////////////////////////////////////////////////////////////

  ///\e
  
  ///\relates XmlIo
  ///
  template<class A>
  void xml(XmlIo &x,std::auto_ptr<A> &v)
  {
    if(x.write()) v=new A;
    x(*v);
  }
  
  ///\e
  
  ///\relates XmlIo
  ///
  template<class A,class B>
  void xml(XmlIo &x,std::pair<A,B> &v)
  {
    x("first",v.first);
    x("second",v.second);
  }

  ///\e
  
  ///\relates XmlIo
  ///
  template<class T>
  void xml(XmlIo &x,std::list<T> &v)
  {
    if(x.write())
      for(typename std::list<T>::const_iterator it=v.begin();
          it!=v.end();++it) x("item",*it);
    else while(x.nextTag()=="item")
      {
        v.push_back(T());
        x("item",v.back());
      }
  }
  ///\e
  
  ///\relates XmlIo
  ///
  template<class T>
  void xml(XmlIo &x,std::vector<T> &v)
  {
    if(x.write())
      for(typename std::vector<T>::const_iterator it=v.begin();
          it!=v.end();++it) x("item",*it);
    else while(x.nextTag()=="item")
      {
        v.push_back(T());
        x("item",v.back());      
      }
  }

  ///\e
  
  ///\relates XmlIo
  ///
  template<class K,class V>
  void xml(XmlIo &x,std::map<K,V> &v)
  {
    if(x.write()) 
      for(typename std::map<K,V>::const_iterator it=v.begin();
          it!=v.end();++it) x("item",*it);
    else while(x.nextTag()=="item")
      {
        typename std::map<K,V>::value_type it;
        x("item",it);
        v.insert(it);
      }
  }

  ///\e
  
  ///\relates XmlIo
  ///
  template<class T>
  void xml(XmlIo &x,lemon::dim2::Point<T> &v)
  {
    { XmlIo::LineTag t(x,"x"); x(v.x); }
    { XmlIo::ContTag t(x,"y"); x(v.y); }
  }

  ///\e
  
  ///\relates XmlIo
  ///
  template<class T>
  void xml(XmlIo &x,lemon::dim2::Box<T> &v)
  {
    if(x.write()) {
      if(!v.empty()) {
        x("point",v.bottomLeft());
        if(v.bottomLeft()!=v.topRight()) x("point",v.topRight());
      }
    }
    else {
      v.clear();
      while(x.nextTag()=="point") {
        lemon::dim2::Point<T> co;
        x("point",co);
        v.add(co);
      }
    }
  }
  
}

#endif