tree.cc

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#include "tree.h"
#include <boost/spirit/core.hpp>

namespace {
  using namespace boost::spirit;
  using std::string;
  using namespace opencog;

  tree<string> tr;
  tree<string>::iterator at=tr.begin();

  void begin_internal(const char* from, const char* to) {
    at= tr.empty() 
      ? tr.insert(at,string(from,to-1))
      : tr.append_child(at,string(from,to-1));
  }
  void end_internal(const char) {
    at=tr.parent(at);
  }
  void add_leaf(const char* from, const char* to) {
    if (tr.empty())
      at=tr.insert(at,string(from,to));
    else
      tr.append_child(at,string(from,to));
  }

  struct TreeGrammar : public grammar<TreeGrammar> {
    std::vector<string> v;
    
    template<typename ScannerT>
    struct definition {
      definition(const TreeGrammar&) {
    term= 
      lexeme_d[//or a message M with the syntax message:"M"
           //added this to parse correctly has_said perceptions
           ( str_p("message:") >> ch_p('"') 
               >> *(anychar_p - ch_p('"')) >> ch_p('"'))
           | (+( anychar_p - ch_p('(') - ch_p(')') - space_p))]
      [&add_leaf];
    beg=
      lexeme_d[(+( anychar_p - ch_p('(') - ch_p(')') - space_p)) >> '('];
    expr=
      (beg[&begin_internal] >> +expr >> ch_p(')')[&end_internal]) |
      term;
    //expr=term | (term >> '(' >> +expr >> ')');
      }
      rule<ScannerT> expr,beg,term;
      
      const rule<ScannerT>& start() const { return expr; }
    };
  };

  tree<std::string> parse_string_tree(const std::string& str) {
    TreeGrammar tg;
    tr.clear();
    at=tr.begin();
    parse(str.c_str(),tg,space_p);
    
    tree<std::string> tmp(tr);
    tr.clear();
    return tmp;
  }
} //~namespace

std::istream& operator>>(std::istream& in,opencog::tree<std::string>& t) throw (InconsistenceException, std::bad_exception) {
  t.clear();
  std::string str,tmp;
  int nparen=0;
  do {
    //replaced by getline so that a message i.e. "yo  man" isn't
    //replaced by "yo man" (where a space is missing)
    //Other assumption : no '(' and ')' between " "
    std::getline(in, tmp);
    nparen+=count(tmp.begin(),tmp.end(),'(')-count(tmp.begin(),tmp.end(),')');
    str+=tmp+' ';
  } while (in.good() && nparen>0);
  if (nparen!=0) {
    std::stringstream stream (std::stringstream::out);
    stream << "Paren mismatch parsing tree: '" << str << "'" << std::endl;
    throw InconsistenceException(TRACE_INFO, "tree - %s.",
                 stream.str().c_str());
  }
  t=parse_string_tree(str);
  return in;
}