#ifndef PRD_SEQUENCEITERATOR_HXX
#define PRD_SEQUENCEITERATOR_HXX

#ifndef   PRD_GLOBALS_HXX
#include "PRD_Globals.hxx"
#endif

class SequenceIterator {
private:

    const char *sequence;       // sequence of bases to be iterated
    int         max_length;     // maximum count of bases returned (afterwards only EOS is returned)
    int         stop_position;  // stop at this position even if not yet max_length bases delivered
    int         direction;      // direction to walk through sequence (FORWARD / BACKWARD)

public:
    static const int  IGNORE   = -1;     // may be used at max_length_ or stop_pos_ parameter
    static const char EOS      = '\x00'; // = End Of Sequence
    static const int  FORWARD  = 1;      // may be used at direction_ parameter
    static const int  BACKWARD = -1;     // may be used at direction_ parameter

    PRD_Sequence_Pos pos;       // current index in sequence .. position of last returned base
    int              delivered; // current count of returned bases

    SequenceIterator (const char *sequence_, PRD_Sequence_Pos start_pos_, PRD_Sequence_Pos stop_pos_, int max_length_, int direction_);
    SequenceIterator (const char *sequence);

    void restart (PRD_Sequence_Pos start_pos_, PRD_Sequence_Pos stop_pos_, int max_length_, int direction_);
    unsigned char nextBase();
};

#else
#error PRD_SequenceIterator.hxx included twice
#endif // PRD_SEQUENCEITERATOR_HXX