HeaderFromStream.cpp

#include "HeaderFromStream.h"

using namespace img;

HdrRecordBase*
ReadASCIIHeader(string in) {

  const char quote='\'';	//will bound a quoted string keyword or value
  const string comments="/";	//starts comment (unless quoted)
  const char eq='=';	//can be present after keyword

  string keyword;
  string vstring;
  string comment;

  string::size_type i=0;
  string::size_type l=in.length();

  // skip opening white space:
  while (i<l && isspace(in[i])) ++i;
  if (i==l) return 0;

  //Keyword ends at next white, =, comment, or end:
  while (i<l 
	 && in[i]!=quote
	 && in[i]!=eq
	 && !isspace(in[i])
	 && comments.find(in[i])==string::npos ) keyword+=in[i++];
  if (keyword.length()==0) return 0;	//no useful info.

  //**/cerr << "Working on keyword <" << keyword << ">" << endl;
  // Skip whitespace or equals; done for end or comment
  while (i<l && (in[i]==eq || isspace(in[i])) ) ++i;

  // Null record if we have nothing or comment left:
  if (i==l) return new HdrRecordNull(keyword);
  if (comments.find(in[i])!=string::npos) return new HdrRecordNull(keyword, in.substr(i+1));

  // A keyword named "HISTORY" or "COMMENT" is all comment, really
  if (keyword=="COMMENT" || keyword=="HISTORY")
    return new HdrRecordNull(keyword, in.substr(i));

  // A quoted value is string:
  if (in[i]==quote) {
    //If value is quoted, get everything until next quote
    ++i;	//skip the quote
    while (i<l && in[i]!=quote) vstring+=in[i++];
    if (i==l) return 0;	// unbounded quote, failure!!!
    ++i;	//skip the closing quote
    while (i<l && isspace(in[i])) i++;	// skip whitespace
    //**/cerr << "Got string: " << vstring << endl;
    if (i==l) return new HdrRecord<string>(keyword, vstring);
    else if (comments.find(in[i])!=string::npos) // Comment left?
      return new HdrRecord<string>(keyword, vstring, in.substr(i+1));
    else return 0; // ??? failure - something other than comment after string
  }

  if (in[i]=='T' || in[i]=='F') {
    // Boolean valued:
    bool value= (in[i]=='T');
    i++;
    while (i<l && isspace(in[i])) i++;	// skip whitespace
    if (i==l) return new HdrRecord<bool>(keyword, value);
    else if (comments.find(in[i])!=string::npos) // Comment left?
      return new HdrRecord<bool>(keyword, value, in.substr(i+1));
    else return 0; // ??? failure - something other than comment after T/F
  }

  // Otherwise we are getting either an integer or a float (ignore complex)
  while (i<l && comments.find(in[i])==string::npos ) vstring+=in[i++];
  // Strip trailing whitespace if was not a quoted response:
  string::size_type pos = vstring.size();
  while (pos > 0 && isspace(vstring[pos - 1])) pos--;
  vstring.erase(pos);
  //**/cerr << "Getting value from string: " << vstring << endl;
  // Collect comment
  if (comments.find(in[i])!=string::npos) // Comment left?
    comment = in.substr(i+1);
  HdrRecord<int>* hi = new HdrRecord<int>(keyword, 0, comment);
  if (!hi->setValueString(vstring)) return hi;
  // If that failed, try a double
  HdrRecord<double>* hd = new HdrRecord<double>(keyword, 0., comment);
  if (!hd->setValueString(vstring)) return hd;
  else return 0;	// Formatting error
}

Header
img::HeaderFromStream(istream& is) {
  Header h;
  string buffer;
  while (getline(is, buffer)) {
    HdrRecordBase* hrb = ReadASCIIHeader(buffer);
    if (!hrb) 
      FormatAndThrow<HeaderError>() << "Bad ASCII header card <" << buffer << ">";
    if (hrb->getKeyword()=="END") return h;
    else if (hrb->getKeyword()=="COMMENT") h.addComment(hrb->getComment());
    else if (hrb->getKeyword()=="HISTORY") h.addHistory(hrb->getComment());
    else h.append(hrb);
  }
  return h;
}

ostream&
operator<<(ostream& os,
	   const img::Header& h) {
  for (h.rewind(); !h.atEnd(); h.incr())
    os << h.current()->writeCard() << endl;
  os << "END     " << endl;
  return os;
}