1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
require 'spec_helper'
describe Immutable::Vector do
describe '#repeated_permutation' do
let(:vector) { V[1,2,3,4] }
context 'without a block' do
context 'and without argument' do
it 'returns an Enumerator of all repeated permutations' do
vector.repeated_permutation.class.should be(Enumerator)
vector.repeated_permutation.to_a.sort.should eql(vector.to_a.repeated_permutation(4).to_a.sort)
end
end
context 'with an integral argument' do
it 'returns an Enumerator of all repeated permutations of the given length' do
vector.repeated_permutation(2).class.should be(Enumerator)
vector.repeated_permutation(2).to_a.sort.should eql(vector.to_a.repeated_permutation(2).to_a.sort)
vector.repeated_permutation(3).class.should be(Enumerator)
vector.repeated_permutation(3).to_a.sort.should eql(vector.to_a.repeated_permutation(3).to_a.sort)
end
end
end
context 'with a block' do
it 'returns self' do
vector.repeated_permutation {}.should be(vector)
end
context 'on an empty vector' do
it 'yields the empty permutation' do
yielded = []
V.empty.repeated_permutation { |obj| yielded << obj }
yielded.should eql([[]])
end
end
context 'with an argument of zero' do
it 'yields the empty permutation' do
yielded = []
vector.repeated_permutation(0) { |obj| yielded << obj }
yielded.should eql([[]])
end
end
context 'with no argument' do
it 'yields all repeated permutations' do
yielded = []
V[1,2,3].repeated_permutation { |obj| yielded << obj }
yielded.sort.should eql([[1,1,1], [1,1,2], [1,1,3], [1,2,1], [1,2,2],
[1,2,3], [1,3,1], [1,3,2], [1,3,3], [2,1,1], [2,1,2], [2,1,3], [2,2,1],
[2,2,2], [2,2,3], [2,3,1], [2,3,2], [2,3,3], [3,1,1], [3,1,2], [3,1,3],
[3,2,1], [3,2,2], [3,2,3], [3,3,1], [3,3,2], [3,3,3]])
end
end
context 'with a positive integral argument' do
it 'yields all repeated permutations of the given length' do
yielded = []
vector.repeated_permutation(2) { |obj| yielded << obj }
yielded.sort.should eql([[1,1], [1,2], [1,3], [1,4], [2,1], [2,2], [2,3], [2,4],
[3,1], [3,2], [3,3], [3,4], [4,1], [4,2], [4,3], [4,4]])
end
end
end
it 'handles duplicate elements correctly' do
V[10,11,10].repeated_permutation(2).sort.should eql([[10, 10], [10, 10],
[10, 10], [10, 10], [10, 11], [10, 11], [11, 10], [11, 10], [11, 11]])
end
it 'allows permutations larger than the number of elements' do
V[1,2].repeated_permutation(3).sort.should eql(
[[1, 1, 1], [1, 1, 2], [1, 2, 1],
[1, 2, 2], [2, 1, 1], [2, 1, 2],
[2, 2, 1], [2, 2, 2]])
end
it 'leaves the original unmodified' do
vector.repeated_permutation(2) {}
vector.should eql(V[1,2,3,4])
end
it 'behaves like Array#repeated_permutation' do
10.times do
array = rand(8).times.map { rand(10000) }
vector = V.new(array)
perm_size = array.size == 0 ? 0 : rand(array.size)
array.repeated_permutation(perm_size).to_a.should == vector.repeated_permutation(perm_size).to_a
end
end
end
end
|
