Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
GNestedIterator |
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| 1.8888888888888888;1,889 |
1 | /* | |
2 | This file is part of Combean. | |
3 | ||
4 | Combean is free software; you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 2 of the License, or | |
7 | (at your option) any later version. | |
8 | ||
9 | Combean is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with Combean; if not, write to the Free Software | |
16 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | package net.sourceforge.combean.util; | |
19 | ||
20 | import net.sourceforge.combean.util.except.UnsupportedMethodException; | |
21 | import net.sourceforge.combean.interfaces.base.ResettableIterator; | |
22 | ||
23 | /** | |
24 | * An iterator composed of | |
25 | * | |
26 | * - an outer iterator | |
27 | * - a closure that generates an inner iterator for every element of the outer | |
28 | * iteration. It is called with the current outer iteration value as argument. | |
29 | * | |
30 | * The nested iterator iterates through all pairs of the outer and inner iteration | |
31 | * and returns ONLY the element of the inner iteration as result of next(). | |
32 | */ | |
33 | class GNestedIterator implements Iterator { | |
34 | ||
35 | private Iterator itOuter; | |
36 | private Closure getInnerItForOuter; | |
37 | ||
38 | private Iterator itInner; | |
39 | private boolean outerTerminated; | |
40 | private boolean allTerminated; | |
41 | private Object outerObject; | |
42 | ||
43 | public GNestedIterator(Iterable outerIterable, Closure getInnerItForOuter) { | |
44 | 25 | init(outerIterable.iterator(), getInnerItForOuter); |
45 | } | |
46 | ||
47 | public GNestedIterator(Iterator itOuter, Closure getInnerItForOuter) { | |
48 | 1905 | init(itOuter, getInnerItForOuter); |
49 | } | |
50 | ||
51 | private init(Iterator itOuter, Closure getInnerItForOuter) { | |
52 | 1930 | this.itOuter = itOuter; |
53 | 1930 | this.getInnerItForOuter = getInnerItForOuter; |
54 | ||
55 | 1930 | this.outerTerminated = false; |
56 | 1930 | this.allTerminated = false; |
57 | 1930 | nextOuter(); |
58 | ||
59 | 1925 | if (this.outerTerminated) { |
60 | 5 | this.allTerminated = true; |
61 | } | |
62 | } | |
63 | ||
64 | protected Object getOuter() { | |
65 | 290 | return this.outerObject; |
66 | } | |
67 | ||
68 | public void remove() { | |
69 | 0 | throw new UnsupportedMethodException(); |
70 | } | |
71 | ||
72 | boolean hasNext() { | |
73 | 9960 | if (this.allTerminated) { |
74 | 5 | return false; |
75 | } | |
76 | 9955 | advanceOuterToNonEmptyInner(); |
77 | 9955 | return !this.outerTerminated || this.itInner.hasNext(); |
78 | } | |
79 | ||
80 | Object next() { | |
81 | 6805 | advanceOuterToNonEmptyInner(); |
82 | 6805 | assert this.itInner.hasNext(); |
83 | 6805 | Object innerObject = this.itInner.next(); |
84 | 6805 | return innerObject; |
85 | } | |
86 | ||
87 | private boolean nextOuter() { | |
88 | 8580 | if (!itOuter.hasNext()) { |
89 | 1925 | this.outerTerminated = true; |
90 | } | |
91 | else { | |
92 | 6655 | this.outerObject = this.itOuter.next(); |
93 | 6655 | Object itInnerDef = this.getInnerItForOuter.call(this.outerObject); |
94 | 6650 | if (itInnerDef instanceof Iterable) { |
95 | 50 | this.itInner = itInnerDef.iterator(); |
96 | } | |
97 | else { | |
98 | 6600 | this.itInner = itInnerDef; |
99 | } | |
100 | 6650 | assert this.itInner != null; |
101 | } | |
102 | 8575 | return !this.outerTerminated; |
103 | } | |
104 | ||
105 | ||
106 | private void advanceOuterToNonEmptyInner() { | |
107 | 21490 | while (!this.itInner.hasNext()) { |
108 | 6650 | if (!nextOuter()) { |
109 | 1920 | break; |
110 | } | |
111 | } | |
112 | } | |
113 | } |