#include "CLucene/StdHeader.h"
#include "FastCharStream.h"

#include "CLucene/util/Arrays.h"
#include "CLucene/util/Reader.h"

namespace lucene{ namespace util {

  //Initializes a new instance of the FastCharStream class LUCENE_EXPORT.
  FastCharStream::FastCharStream(Reader& reader):
    input(reader),
    col(1),
    line(1)
  {
  }

  //Returns the next char_t from the stream.
  uchar_t FastCharStream::GetNext()	{
    /* WDG: UTF8 Reader.readChar will throw if it tries to read past the end so 
	        no need to do it twice */  
	#ifndef UTF8    
    if (Eos())
    {
      /* DSR:CL_BUG: Calling QueryParser::Parse("\\", ..., ...) triggered this
      ** case, which didn't use a throw type that the QueryParser could handle,
      ** resulting in "abnormal program termination"/"abort".  I switched from
      **   throw "...";
      ** to
      **   _THROWC("...");  */
      _THROWC("warning : FileReader.GetNext : Read char_t over EOS.");
      /* DSR: The next statement is unreachable, isn't it? */
      return '\0';
    }
	#endif
    uchar_t ch = input.readChar();
    col = input.position()+1;

    if(ch == '\n')
    {
      line++;
      col = 1;
    }

    return ch;
  }

  void FastCharStream::UnGet(){
    if ( input.position() == 0 )
      _THROWC("error : FileReader.UnGet : ungetted first char_t");

    input.seek(input.position()-1);
  }

  //Returns the current top char_t from the input stream without removing it.
  uchar_t FastCharStream::Peek(){
    try{
      return input.peek();
    }catch(...){}
    return 0;
  }


  //Returns <b>True</b> if the end of stream was reached.
  bool FastCharStream::Eos()	{
    return input.available()==0;
  }

  // Gets the current column.
  int_t FastCharStream::Column() {
    return col;
  }

  // Gets the current line.
  int_t FastCharStream::Line() {
    return line;
  }
}}