tag.cpp

Jabber code library, developed with c

//             printf( "adding %s to result set\n", name().c_str() );
            result.push_back( this );
          }
        }
//         else
//           printf( "found %s != %s\n", token->name().c_str(), name().c_str() );

        break;
      }
      case XTDoubleSlash:
      {
//         printf( "in XTDoubleSlash\n" );
        Tag *t = token->clone();
//         printf( "original token: %s\ncloned token: %s\n", token->xml().c_str(), n->xml().c_str() );
        t->addAttribute( "type", XTElement );
        add( result, evaluateTagList( t ) );
        const Tag::TagList& res2 = allDescendants();
        Tag::TagList::const_iterator it = res2.begin();
        for( ; it != res2.end(); ++it )
        {
          add( result, (*it)->evaluateTagList( t ) );
        }
        delete t;
        break;
      }
      case XTDot:
      {
        const Tag::TagList& tokenChildren = token->children();
        if( !tokenChildren.empty() )
        {
          add( result, evaluateTagList( tokenChildren.front() ) );
        }
        else
          result.push_back( this );
        break;
      }
      case XTDoubleDot:
      {
//         printf( "in XTDoubleDot\n" );
        if( m_parent )
        {
          const Tag::TagList& tokenChildren = token->children();
          if( tokenChildren.size() )
          {
            Tag *testtoken = tokenChildren.front();
            if( testtoken->name() == "*" )
            {
              add( result, m_parent->evaluateTagList( testtoken ) );
            }
            else
            {
              Tag *t = token->clone();
              t->addAttribute( "type", XTElement );
              t->m_name = m_parent->m_name;
              add( result, m_parent->evaluateTagList( t ) );
              delete t;
            }
          }
          else
          {
            result.push_back( m_parent );
          }
        }
      }
      case XTInteger:
      {
        const Tag::TagList& l = token->children();
        if( !l.size() )
          break;

        const Tag::TagList& res = evaluateTagList( l.front() );

        int pos = atoi( token->name().c_str() );
//         printf( "checking index %d\n", pos );
        if( pos > 0 && pos <= (int)res.size() )
        {
          Tag::TagList::const_iterator it = res.begin();
          while ( --pos )
          {
            ++it;
          }
          result.push_back( *it );
        }
        break;
      }
      default:
        break;
    }
    return result;
  }

  bool Tag::evaluateBoolean( Tag *token )
  {
    if( !token )
      return false;

    bool result = false;
    TokenType tokenType = (TokenType)atoi( token->findAttribute( "type" ).c_str() );
    switch( tokenType )
    {
      case XTAttribute:
        if( token->name() == "*" && m_attribs.size() )
          result = true;
        else
          result = hasAttribute( token->name() );
        break;
      case XTOperatorEq:
        result = evaluateEquals( token );
        break;
      case XTOperatorLt:
        break;
      case XTOperatorLtEq:
        break;
      case XTOperatorGtEq:
        break;
      case XTOperatorGt:
        break;
      case XTUnion:
      case XTElement:
      {
        Tag *t = new Tag( "." );
        t->addAttribute( "type", XTDot );
        t->addChild( token );
        result = !evaluateTagList( t ).empty();
        t->removeChild( token );
        delete t;
        break;
      }
      default:
        break;
    }

    return result;
  }

  bool Tag::evaluateEquals( Tag *token )
  {
    if( !token || token->children().size() != 2 )
      return false;

    bool result = false;
    Tag::TagList::const_iterator it = token->children().begin();
    Tag *ch1 = (*it);
    Tag *ch2 = (*++it);

    TokenType tt1 = (TokenType)atoi( ch1->findAttribute( "type" ).c_str() );
    TokenType tt2 = (TokenType)atoi( ch2->findAttribute( "type" ).c_str() );
    switch( tt1 )
    {
      case XTAttribute:
        switch( tt2 )
        {
          case XTInteger:
          case XTLiteral:
            result = ( findAttribute( ch1->name() ) == ch2->name() );
            break;
          case XTAttribute:
            result = ( hasAttribute( ch1->name() ) && hasAttribute( ch2->name() ) &&
                      findAttribute( ch1->name() ) == findAttribute( ch2->name() ) );
            break;
          default:
            break;
        }
        break;
      case XTInteger:
      case XTLiteral:
        switch( tt2 )
        {
          case XTAttribute:
            result = ( ch1->name() == findAttribute( ch2->name() ) );
            break;
          case XTLiteral:
          case XTInteger:
            result = ( ch1->name() == ch2->name() );
            break;
          default:
            break;
        }
        break;
      default:
        break;
    }

    return result;
  }

  Tag::TagList Tag::allDescendants()
  {
    Tag::TagList result;
    Tag::TagList::const_iterator it = m_children.begin();
    for( ; it != m_children.end(); ++it )
    {
      result.push_back( (*it) );
      add( result, (*it)->allDescendants() );
    }
    return result;
  }

  Tag::TagList Tag::evaluateUnion( Tag *token )
  {
    Tag::TagList result;
    if( !token )
      return result;

    const Tag::TagList& l = token->children();
    Tag::TagList::const_iterator it = l.begin();
    for( ; it != l.end(); ++it )
    {
      add( result, evaluateTagList( (*it) ) );
    }
    return result;
  }

  void Tag::closePreviousToken( Tag** root, Tag** current, Tag::TokenType& type, std::string& tok )
  {
    if( !tok.empty() )
    {
      addToken( root, current, type, tok );
      type = XTElement;
      tok = "";
    }
  }

  Tag* Tag::parse( const std::string& expression, unsigned& len, Tag::TokenType border )
  {
    Tag *root = 0;
    Tag *current = root;
    std::string token;

//     XPathError error = XPNoError;
//     XPathState state = Init;
//     int expected = 0;
//     bool run = true;
//     bool ws = false;

    Tag::TokenType type  = XTElement;

    char c;
    for( ; len < expression.length(); ++len )
    {
      c = expression[len];
      if( type == XTLiteralInside && c != '\'' )
      {
        token += c;
        continue;
      }

      switch( c )
      {
        case '/':
          closePreviousToken( &root, &current, type, token );

          if( len < expression.length()-1 && expression[len+1] == '/' )
          {
//             addToken( &root, &current, XTDoubleSlash, "//" );
            type = XTDoubleSlash;
            ++len;
          }
//           else
//           {
//             if( !current )
//             addToken( &root, &current, XTSlash, "/" );
//           }
          break;
        case ']':
          closePreviousToken( &root, &current, type, token );
          ++len;
          return root;
        case '[':
        {
          closePreviousToken( &root, &current, type, token );
          Tag *t = parse( expression, ++len, XTRightBracket );
          if( !addPredicate( &root, &current, t ) )
            delete t;
          break;
        }
        case '(':
        {
          closePreviousToken( &root, &current, type, token );
          Tag *t = parse( expression, ++len, XTRightParenthesis );
          if( current )
          {
//             printf( "added %s to %s\n", t->xml().c_str(), current->xml().c_str() );
            t->addAttribute( "argument", "true" );
            current->addChild( t );
          }
          else
          {
            root = t;
//             printf( "made %s new root\n", t->xml().c_str() );
          }
          break;
        }
        case ')':
          closePreviousToken( &root, &current, type, token );
          ++len;
          return root;
        case '\'':
          if( type == XTLiteralInside )
            if( expression[len - 2] == '\\' )
              token[token.length() - 2] = c;
            else
              type = XTLiteral;
          else
            type = XTLiteralInside;
          break;
        case '@':
          type = XTAttribute;
          break;
        case '.':
          token += c;
          if( token.size() == 1 )
          {
            if( len < expression.length()-1 && expression[len+1] == '.' )
            {
              type = XTDoubleDot;
              ++len;
              token += c;
            }
            else
            {
              type = XTDot;
            }
          }
          break;
        case '*':
//           if( !root || ( current && ( current->tokenType() == XTSlash
//                                       || current->tokenType() == XTDoubleSlash ) ) )
//           {
//             addToken( &root, &current, type, "*" );
//             break;
//           }
          addToken( &root, &current, type, "*" );
          type = XTElement;
          break;
        case '+':
        case '>':
        case '<':
        case '=':
        case '|':
        {
          closePreviousToken( &root, &current, type, token );
          std::string s( 1, c );
          Tag::TokenType ttype = getType( s );
          if( ttype <= border )
            return root;
          Tag *t = parse( expression, ++len, ttype );
          addOperator( &root, &current, t, ttype, s );
          if( border == XTRightBracket )
            return root;
          break;
        }
        default:
          token += c;
      }
    }

    if( !token.empty() )
      addToken( &root, &current, type, token );

//     if( error != XPNoError )
//       printf( "error: %d\n", error );
    return root;
  }

  void Tag::addToken( Tag **root, Tag **current, Tag::TokenType type,
                      const std::string& token )
  {
    Tag *t = new Tag( token );
    if( t->isNumber() && !t->children().size() )
      type = XTInteger;
    t->addAttribute( "type", type );

    if( *root )
    {
//       printf( "new current %s, type: %d\n", token.c_str(), type );
      (*current)->addChild( t );
      *current = t;
    }
    else
    {
//       printf( "new root %s, type: %d\n", token.c_str(), type );
      *current = *root = t;
    }
  }

  void Tag::addOperator( Tag **root, Tag **current, Tag *arg,
                           Tag::TokenType type, const std::string& token )
  {
    Tag *t = new Tag( token );
    t->addAttribute( "type", type );
//     printf( "new operator: %s (arg1: %s, arg2: %s)\n", t->name().c_str(), (*root)->xml().c_str(),
//                                                                           arg->xml().c_str() );
    t->addAttribute( "operator", "true" );
    t->addChild( *root );
    t->addChild( arg );
    *current = *root = t;
  }

  bool Tag::addPredicate( Tag **root, Tag **current, Tag *token )
  {
    if( !*root || !*current )
      return false;

    if( ( token->isNumber() && !token->children().size() ) || token->name() == "+" )
    {
//       printf( "found Index %s, full: %s\n", token->name().c_str(), token->xml().c_str() );
      if( !token->hasAttribute( "operator", "true" ) )
      {
        token->addAttribute( "type", XTInteger );
      }
      if( *root == *current )
      {
        *root = token;
//         printf( "made Index new root\n" );
      }
      else
      {
        (*root)->removeChild( *current );
        (*root)->addChild( token );
//         printf( "added Index somewhere between root and current\n" );
      }
      token->addChild( *current );
//       printf( "added Index %s, full: %s\n", token->name().c_str(), token->xml().c_str() );
    }
    else
    {
      token->addAttribute( "predicate", "true" );
      (*current)->addChild( token );
    }

    return true;
  }

  Tag::TokenType Tag::getType( const std::string& c )
  {
    if( c == "|" )
      return XTUnion;
    if( c == "<" )
      return XTOperatorLt;
    if( c == ">" )
      return XTOperatorGt;
    if( c == "*" )
      return XTOperatorMul;
    if( c == "+" )
      return XTOperatorPlus;
    if( c == "=" )
      return XTOperatorEq;

    return XTNone;
  }

  bool Tag::isWhitespace( const char c )
  {
    return ( c == 0x09 || c == 0x0a || c == 0x0d || c == 0x20 );
  }

  bool Tag::isNumber()
  {
    if( m_name.empty() )
      return false;

    std::string::size_type l = m_name.length();
    std::string::size_type i = 0;
    while( i < l && isdigit( m_name[i] ) )
      ++i;
    return i == l;
  }

  void Tag::add( Tag::TagList& one, const Tag::TagList& two )
  {
    Tag::TagList::const_iterator it = two.begin();
    for( ; it != two.end(); ++it )
      if( std::find( one.begin(), one.end(), (*it) ) == one.end() )
        one.push_back( (*it) );
  }

}