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comparison tango/tango/util/collection/impl/AbstractIterator.d @ 132:1700239cab2e trunk

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[svn r136] MAJOR UNSTABLE UPDATE!!! Initial commit after moving to Tango instead of Phobos. Lots of bugfixes... This build is not suitable for most things.
author lindquist
date Fri, 11 Jan 2008 17:57:40 +0100
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131:5825d48b27d1 132:1700239cab2e
1 /*
2 File: AbstractIterator.d
3
4 Originally written by Doug Lea and released into the public domain.
5 Thanks for the assistance and support of Sun Microsystems Labs, Agorics
6 Inc, Loral, and everyone contributing, testing, and using this code.
7
8 History:
9 Date Who What
10 24Sep95 dl@cs.oswego.edu Create from tango.util.collection.d working file
11 13Oct95 dl Changed protection statuses
12 9Apr97 dl made class public
13 */
14
15
16 module tango.util.collection.impl.AbstractIterator;
17
18 private import tango.core.Exception;
19
20 private import tango.util.collection.model.View,
21 tango.util.collection.model.GuardIterator;
22
23
24
25 /**
26 *
27 * A convenient base class for implementations of GuardIterator
28 *
29 author: Doug Lea
30 * @version 0.93
31 *
32 * <P> For an introduction to this package see <A HREF="index.html"> Overview </A>.
33 **/
34
35 public abstract class AbstractIterator(T) : GuardIterator!(T)
36 {
37 /**
38 * The collection being enumerated
39 **/
40
41 private View!(T) view;
42
43 /**
44 * The version number of the collection we got upon construction
45 **/
46
47 private uint mutation;
48
49 /**
50 * The number of elements we think we have left.
51 * Initialized to view.size() upon construction
52 **/
53
54 private uint togo;
55
56
57 protected this (View!(T) v)
58 {
59 view = v;
60 togo = v.size();
61 mutation = v.mutation();
62 }
63
64 /**
65 * Implements tango.util.collection.impl.Collection.CollectionIterator.corrupted.
66 * Claim corruption if version numbers differ
67 * See_Also: tango.util.collection.impl.Collection.CollectionIterator.corrupted
68 **/
69
70 public final bool corrupted()
71 {
72 return mutation != view.mutation;
73 }
74
75 /**
76 * Implements tango.util.collection.impl.Collection.CollectionIterator.numberOfRemaingingElements.
77 * See_Also: tango.util.collection.impl.Collection.CollectionIterator.remaining
78 **/
79 public final uint remaining()
80 {
81 return togo;
82 }
83
84 /**
85 * Implements tango.util.collection.model.Iterator.more.
86 * Return true if remaining > 0 and not corrupted
87 * See_Also: tango.util.collection.model.Iterator.more
88 **/
89 public final bool more()
90 {
91 return togo > 0 && mutation is view.mutation;
92 }
93
94 /**
95 * Subclass utility.
96 * Tries to decrement togo, raising exceptions
97 * if it is already zero or if corrupted()
98 * Always call as the first line of get.
99 **/
100 protected final void decRemaining()
101 {
102 if (mutation != view.mutation)
103 throw new CorruptedIteratorException ("Collection modified during iteration");
104
105 if (togo is 0)
106 throw new NoSuchElementException ("exhausted enumeration");
107
108 --togo;
109 }
110 }
111
112
113 public abstract class AbstractMapIterator(K, V) : AbstractIterator!(V), PairIterator!(K, V)
114 {
115 abstract V get (inout K key);
116
117 protected this (View!(V) c)
118 {
119 super (c);
120 }
121 }