ksirc/stringparserstate.h

   1 #ifndef __stringparserstate_h__
   2 #define __stringparserstate_h__
   3
   4 // ### optimize me: it's stupid to do a linear search for each
   5 // atEnd() invocation. This should be done once in the ctor and
   6 // end() should be set appropriately
   7 template <typename CharType, typename _SizeType = size_t>
   8 class StringParserState
   9 {
  10 public:
  11     typedef CharType ValueType;
  12     typedef const CharType * ConstIterator;
  13     typedef _SizeType SizeType;
  14     typedef QList<ValueType> ValueList;
  15
  16     StringParserState( ConstIterator start, SizeType maxSteps,
  17                        const ValueList &optionalEndItems = ValueList() )
  18     {
  19         m_begin = start;
  20         m_current = start;
  21         m_end = start + maxSteps;
  22         m_endItems = optionalEndItems;
  23     }
  24
  25     void operator++() { ++m_current; }
  26
  27     bool atBegin() const
  28     {
  29         return m_current == m_begin;
  30     }
  31
  32     bool atEnd() const
  33     {
  34         if ( m_current >= m_end )
  35             return true;
  36         return m_endItems.findIndex( currentValue() ) != -1;
  37     }
  38
  39     ConstIterator current() const { return m_current; }
  40     ValueType currentValue() const { return *current(); }
  41
  42     ConstIterator begin() const { return m_begin; }
  43     ConstIterator end() const { return m_end; }
  44
  45     SizeType stepsLeft() const { return m_end - m_current; }
  46
  47     SizeType advanceTo( ValueType val )
  48     {
  49         ConstIterator start = m_current;
  50         while ( !atEnd() && currentValue() != val )
  51             ++m_current;
  52         return m_current - start;
  53     }
  54
  55     SizeType skip( ValueType valueToIgnore )
  56     {
  57         ConstIterator start = m_current;
  58         while ( !atEnd() && currentValue() == valueToIgnore )
  59             ++m_current;
  60         return m_current - start;
  61     }
  62
  63 private:
  64     ConstIterator m_begin;
  65     ConstIterator m_current;
  66     ConstIterator m_end;
  67     ValueList m_endItems;
  68 };
  69
  70 #endif
  71