Mercurial > lasercutter

     1 /**

     2  * Copyright (c) Rich Hickey. All rights reserved.

     3  * The use and distribution terms for this software are covered by the

     4  * Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)

     5  * which can be found in the file epl-v10.html at the root of this distribution.

     6  * By using this software in any fashion, you are agreeing to be bound by

     7  * the terms of this license.

     8  * You must not remove this notice, or any other, from this software.

     9  */

    10 

    11 package clojure.lang;

    12 

    13 import java.io.PushbackReader;

    14 import java.io.Reader;

    15 import java.io.LineNumberReader;

    16 import java.io.IOException;

    17 

    18 

    19 public class LineNumberingPushbackReader extends PushbackReader{

    20 

    21 // This class is a PushbackReader that wraps a LineNumberReader. The code

    22 // here to handle line terminators only mentions '\n' because

    23 // LineNumberReader collapses all occurrences of CR, LF, and CRLF into a

    24 // single '\n'.

    25 

    26 private static final int newline = (int) '\n';

    27 

    28 private boolean _atLineStart = true;

    29 private boolean _prev;

    30 

    31 public LineNumberingPushbackReader(Reader r){

    32 	super(new LineNumberReader(r));

    33 }

    34 

    35 public int getLineNumber(){

    36 	return ((LineNumberReader) in).getLineNumber() + 1;

    37 }

    38 

    39 public int read() throws IOException{

    40     int c = super.read();

    41     _prev = _atLineStart;

    42     _atLineStart = (c == newline) || (c == -1);

    43     return c;

    44 }

    45 

    46 public void unread(int c) throws IOException{

    47     super.unread(c);

    48     _atLineStart = _prev;

    49 }

    50 

    51 public String readLine() throws IOException{

    52     int c = read();

    53     String line;

    54     switch (c) {

    55     case -1:

    56         line = null;

    57         break;

    58     case newline:

    59         line = "";

    60         break;

    61     default:

    62         String first = String.valueOf((char) c);

    63         String rest = ((LineNumberReader)in).readLine();

    64         line = (rest == null) ? first : first + rest;

    65         _prev = false;

    66         _atLineStart = true;

    67         break;

    68     }

    69     return line;

    70 }

    71 

    72 public boolean atLineStart(){

    73     return _atLineStart;

    74 }

    75 }
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 21 Aug 2010 06:25:44 -0400
parents
children