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
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
// Copyright Louis Dionne 2013-2017
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#ifndef BOOST_HANA_TEST_AUTO_UNFOLDS_HPP
#define BOOST_HANA_TEST_AUTO_UNFOLDS_HPP
#include <boost/hana/assert.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/fold_left.hpp>
#include <boost/hana/fold_right.hpp>
#include <boost/hana/if.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/optional.hpp>
#include <boost/hana/plus.hpp>
#include <boost/hana/unfold_left.hpp>
#include <boost/hana/unfold_right.hpp>
#include <laws/base.hpp>
#include <support/minimal_product.hpp>
#include "test_case.hpp"
TestCase test_unfold_left{[]{
namespace hana = boost::hana;
hana::test::_injection<0> f{};
auto stop_at = [=](auto stop) {
return [=](auto x) {
return hana::if_(hana::equal(stop, x),
hana::nothing,
hana::just(::minimal_product(x + hana::int_c<1>, f(x)))
);
};
};
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<0>)),
MAKE_TUPLE()
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<1>)),
MAKE_TUPLE(f(hana::int_c<0>))
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<2>)),
MAKE_TUPLE(f(hana::int_c<1>), f(hana::int_c<0>))
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<3>)),
MAKE_TUPLE(f(hana::int_c<2>), f(hana::int_c<1>), f(hana::int_c<0>))
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<4>)),
MAKE_TUPLE(f(hana::int_c<3>), f(hana::int_c<2>), f(hana::int_c<1>), f(hana::int_c<0>))
));
}};
TestCase test_unfold_right{[]{
namespace hana = boost::hana;
hana::test::_injection<0> f{};
auto stop_at = [=](auto stop) {
return [=](auto x) {
return hana::if_(hana::equal(stop, x),
hana::nothing,
hana::just(::minimal_product(f(x), x + hana::int_c<1>))
);
};
};
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<0>)),
MAKE_TUPLE()
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<1>)),
MAKE_TUPLE(f(hana::int_c<0>))
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<2>)),
MAKE_TUPLE(f(hana::int_c<0>), f(hana::int_c<1>))
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<3>)),
MAKE_TUPLE(f(hana::int_c<0>), f(hana::int_c<1>), f(hana::int_c<2>))
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::int_c<0>, stop_at(hana::int_c<4>)),
MAKE_TUPLE(f(hana::int_c<0>), f(hana::int_c<1>), f(hana::int_c<2>), f(hana::int_c<3>))
));
}};
// Make sure unfolds can be reversed under certain conditions.
TestCase test_unfold_undo{[]{
namespace hana = boost::hana;
using hana::test::ct_eq;
auto z = ct_eq<999>{};
auto f = ::minimal_product;
auto g = [=](auto k) {
return hana::if_(hana::equal(k, z),
hana::nothing,
hana::just(k)
);
};
// Make sure the special conditions are met
BOOST_HANA_CONSTANT_CHECK(hana::equal(
g(z),
hana::nothing
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
g(f(ct_eq<0>{}, z)),
hana::just(::minimal_product(ct_eq<0>{}, z))
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
g(f(z, ct_eq<0>{})),
hana::just(::minimal_product(z, ct_eq<0>{}))
));
// Make sure the reversing works
{
auto xs = MAKE_TUPLE();
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::fold_left(xs, z, f), g),
xs
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::fold_right(xs, z, f), g),
xs
));
}
{
auto xs = MAKE_TUPLE(ct_eq<0>{});
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::fold_left(xs, z, f), g),
xs
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::fold_right(xs, z, f), g),
xs
));
}
{
auto xs = MAKE_TUPLE(ct_eq<0>{}, ct_eq<1>{});
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::fold_left(xs, z, f), g),
xs
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::fold_right(xs, z, f), g),
xs
));
}
{
auto xs = MAKE_TUPLE(ct_eq<0>{}, ct_eq<1>{}, ct_eq<2>{});
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_left<TUPLE_TAG>(hana::fold_left(xs, z, f), g),
xs
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unfold_right<TUPLE_TAG>(hana::fold_right(xs, z, f), g),
xs
));
}
}};
#endif // !BOOST_HANA_TEST_AUTO_UNFOLDS_HPP
|
