//
// C++ Implementation: srcuntabifier
//
// Description:
//
//
// Author: Lorenzo Bettini <http://www.lorenzobettini.it>, (C) 2004
//
// Copyright: See COPYING file that comes with this distribution
//
//

#include "srcuntabifier.h"
#include "my_sstream.h"
#include <boost/regex.hpp>

const boost::regex tabexp("[\\t]");

const string
Untabifier::doPreformat(const string &s)
{
  boost::sregex_iterator m1(s.begin(), s.end(), tabexp);
  boost::sregex_iterator m2;

  if (m1 == m2)
  {
    if (s[0] == '\n')
      n_ = 0; // reset char counter
    else
      n_ += s.size();

    return s;
  }

  ostringstream buffer;
  string prefix;
  string suffix;

  for (boost::sregex_iterator it = m1; it != m2; ++it)
  {
    prefix = it->prefix();
    suffix = it->suffix();
    if (prefix.size()) {
      buffer << prefix;
      n_ += prefix.size ();
    }

    int nSpaces = nSpacesPerTab_ - n_ % nSpacesPerTab_;
    buffer << string(nSpaces, ' ');
    n_ += nSpaces;
  }

  if (suffix.size()) {
    buffer << suffix;
    n_ += suffix.size();
  }

  return buffer.str();
}