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 /* rich May 24, 2009 */

    12 

    13 package clojure.lang;

    14 

    15 import java.io.Serializable;

    16 

    17 public final class ArrayChunk implements IChunk, Serializable {

    18 

    19 final Object[] array;

    20 final int off;

    21 final int end;

    22 

    23 public ArrayChunk(Object[] array){

    24 	this(array, 0, array.length);

    25 }

    26 

    27 public ArrayChunk(Object[] array, int off){

    28 	this(array, off, array.length);

    29 }

    30 

    31 public ArrayChunk(Object[] array, int off, int end){

    32 	this.array = array;

    33 	this.off = off;

    34 	this.end = end;

    35 }

    36 

    37 public Object nth(int i){

    38 	return array[off + i];

    39 }

    40 

    41 public Object nth(int i, Object notFound){

    42 	if(i >= 0 && i < count())

    43 		return nth(i);

    44 	return notFound;

    45 }

    46 

    47 public int count(){

    48 	return end - off;

    49 }

    50 

    51 public IChunk dropFirst(){

    52 	if(off==end)

    53 		throw new IllegalStateException("dropFirst of empty chunk");

    54 	return new ArrayChunk(array, off + 1, end);

    55 }

    56 

    57 public Object reduce(IFn f, Object start) throws Exception{

    58 		Object ret = f.invoke(start, array[off]);

    59 		for(int x = off + 1; x < end; x++)

    60 			ret = f.invoke(ret, array[x]);

    61 		return ret;

    62 }

    63 }
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 21 Aug 2010 06:25:44 -0400
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