NewickGrammar.h

#ifndef NEWICKGRAMMAR_H
#define NEWICKGRAMMAR_H

#include <boost/spirit/include/classic_core.hpp>
#include <boost/spirit/include/classic_parse_tree.hpp>

using namespace boost::spirit::classic;

/// Grammar for the Newick formatted tree files.
/// Adapted from one of the Spirit examples
///
struct NewickGrammar : public grammar<NewickGrammar> {
  static const int treeID = 10;      ///< Tree
  static const int nodelistID = 20;  ///< Nodelist
  static const int subtreeID = 30;   ///< Subtree
  static const int fulllabelID = 40; ///< Full label (name plus optional #1)
  static const int branchlenID = 50; ///< Branch length
  static const int cblenID = 60;     ///< Colon plus length
  static const int labelID = 70;     ///< Label
  static const int markerID = 80;    ///< Marker (i.e. the optional #1)

  template <typename ScannerT> struct definition {
    definition(NewickGrammar const & /*self*/) {
      tree = nodelist >> !full_label >> !colon_plus_len >>
             no_node_d[*space_p >> ch_p(';')];

      nodelist = no_node_d[ch_p('(')] >>
                 subtree % (no_node_d[ch_p(',') >> *space_p]) >>
                 no_node_d[ch_p(')')];

      subtree =
          nodelist >> !full_label >> !colon_plus_len >> no_node_d[*space_p] |
          full_label >> !colon_plus_len >> no_node_d[*space_p];

      colon_plus_len = no_node_d[ch_p(':') >> *space_p] >> branch_length;

      branch_length = real_p;

      full_label = no_node_d[ch_p('#')] >> marker |
                   label >> !(no_node_d[ch_p('#')] >> marker);

      label = leaf_node_d[alnum_p >> *(alnum_p | '.' | '_' | '|')];

      marker = leaf_node_d[+alnum_p];
    }

    rule<ScannerT, parser_context<>, parser_tag<treeID> > tree;
    rule<ScannerT, parser_context<>, parser_tag<nodelistID> > nodelist;
    rule<ScannerT, parser_context<>, parser_tag<subtreeID> > subtree;
    rule<ScannerT, parser_context<>, parser_tag<fulllabelID> > full_label;
    rule<ScannerT, parser_context<>, parser_tag<branchlenID> > branch_length;
    rule<ScannerT, parser_context<>, parser_tag<cblenID> > colon_plus_len;
    rule<ScannerT, parser_context<>, parser_tag<labelID> > label;
    rule<ScannerT, parser_context<>, parser_tag<markerID> > marker;

    rule<ScannerT, parser_context<>, parser_tag<treeID> > const &start() const {
      return tree;
    }
  };
};

#endif