Mercurial > lasercutter
comparison src/clojure/lang/IteratorSeq.java @ 10:ef7dbbd6452c
added clojure source goodness
author | Robert McIntyre <rlm@mit.edu> |
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date | Sat, 21 Aug 2010 06:25:44 -0400 |
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9:35cf337adfcf | 10:ef7dbbd6452c |
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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.IOException; | |
14 import java.io.NotSerializableException; | |
15 import java.util.Iterator; | |
16 | |
17 public class IteratorSeq extends ASeq{ | |
18 final Iterator iter; | |
19 final State state; | |
20 | |
21 static class State{ | |
22 volatile Object val; | |
23 volatile Object _rest; | |
24 } | |
25 | |
26 public static IteratorSeq create(Iterator iter){ | |
27 if(iter.hasNext()) | |
28 return new IteratorSeq(iter); | |
29 return null; | |
30 } | |
31 | |
32 IteratorSeq(Iterator iter){ | |
33 this.iter = iter; | |
34 state = new State(); | |
35 this.state.val = state; | |
36 this.state._rest = state; | |
37 } | |
38 | |
39 IteratorSeq(IPersistentMap meta, Iterator iter, State state){ | |
40 super(meta); | |
41 this.iter = iter; | |
42 this.state = state; | |
43 } | |
44 | |
45 public Object first(){ | |
46 if(state.val == state) | |
47 synchronized(state) | |
48 { | |
49 if(state.val == state) | |
50 state.val = iter.next(); | |
51 } | |
52 return state.val; | |
53 } | |
54 | |
55 public ISeq next(){ | |
56 if(state._rest == state) | |
57 synchronized(state) | |
58 { | |
59 if(state._rest == state) | |
60 { | |
61 first(); | |
62 state._rest = create(iter); | |
63 } | |
64 } | |
65 return (ISeq) state._rest; | |
66 } | |
67 | |
68 public IteratorSeq withMeta(IPersistentMap meta){ | |
69 return new IteratorSeq(meta, iter, state); | |
70 } | |
71 | |
72 private void writeObject (java.io.ObjectOutputStream out) throws IOException { | |
73 throw new NotSerializableException(getClass().getName()); | |
74 } | |
75 } |