SourceString.java

//=========================================================================
//
//  Part of PEG parser generator Mouse.
//
//  Copyright (C) 2009, 2010 by Roman R. Redziejowski (www.romanredz.se).
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//
//-------------------------------------------------------------------------
//
//  Change log
//    090701 License changed by the author to Apache v.2.
//    090810 Renamed from 'SourceString' and package name changed.
//   Version 1.2
//    091105 Modified where() to insert three dots.
//
//=========================================================================

package source;


//HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
//
//  Wrapper for parser input in the form of a string.
//
//HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

public class SourceString implements Source
{
  //=====================================================================
  //
  //  Data.
  //
  //=====================================================================
  //-------------------------------------------------------------------
  //  The String.
  //  Note: it is the string given to the constructor, not a copy.
  //-------------------------------------------------------------------
  final String text;

  //=====================================================================
  //
  //  Constructor. Wraps the string 's'.
  //
  //=====================================================================
  public SourceString(String s)
    { text = unescaper.translate(s); }

  //=====================================================================
  //
  //  Interface methods.
  //
  //=====================================================================
  //-------------------------------------------------------------------
  //  Is the wrapper correctly initialized?
  //-------------------------------------------------------------------
  public boolean created()
    { return true; }

  //-------------------------------------------------------------------
  //  Returns end position.
  //-------------------------------------------------------------------
  public int end()
    { return text.length(); }

  //-------------------------------------------------------------------
  //  Returns character at position p.
  //-------------------------------------------------------------------
  public char at(int p)
    { return text.charAt(p); }

  //-------------------------------------------------------------------
  //  Returns characters at positions p through q-1.
  //-------------------------------------------------------------------
  public String at(int p, int q)
    { return text.substring(p,q); }

  //-------------------------------------------------------------------
  //  Describes position p in terms of preceding text.
  //-------------------------------------------------------------------
  public String where(int p)
    {
      if (p>15)
        return "After '... " + text.substring(p-15,p) + "'";
      else if (p>0)
        return "After '" + text.substring(0,p) + "'";
      else
        return "At start";
    }

  /****************************************************************************/
  @Override public String toString()
  {
    return "Source string (" + Integer.toHexString(text.hashCode()) + ")";
  }
}