summaryrefslogtreecommitdiffstats
path: root/Source/cmRange.h
blob: 30af7d2718cbaa6b4aeaa6c773fb97cce1206d95 (plain)
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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#pragma once

#include "cmConfigure.h" // IWYU pragma: keep

#include <algorithm>
#include <functional>
#include <iterator>

namespace RangeIterators {

template <typename Iter, typename UnaryPredicate>
class FilterIterator
{
public:
  using iterator_category = std::bidirectional_iterator_tag;
  using value_type = typename std::iterator_traits<Iter>::value_type;
  using difference_type = typename std::iterator_traits<Iter>::difference_type;
  using pointer = typename std::iterator_traits<Iter>::pointer;
  using reference = typename std::iterator_traits<Iter>::reference;

  FilterIterator(Iter b, Iter e, UnaryPredicate p)
    : Cur(std::move(b))
    , End(std::move(e))
    , Pred(std::move(p))
  {
    this->SatisfyPredicate();
  }

  FilterIterator& operator++()
  {
    ++this->Cur;
    this->SatisfyPredicate();
    return *this;
  }

  FilterIterator& operator--()
  {
    do {
      --this->Cur;
    } while (!this->Pred(*this->Cur));
    return *this;
  }

  bool operator==(FilterIterator const& other) const
  {
    return this->Cur == other.Cur;
  }

  bool operator!=(FilterIterator const& other) const
  {
    return !this->operator==(other);
  }

  auto operator*() const -> decltype(*std::declval<Iter>())
  {
    return *this->Cur;
  }

private:
  void SatisfyPredicate()
  {
    while (this->Cur != this->End && !this->Pred(*this->Cur)) {
      ++this->Cur;
    }
  }

  Iter Cur;
  Iter End;
  UnaryPredicate Pred;
};

template <typename Iter, typename UnaryFunction>
class TransformIterator
{
public:
  using iterator_category = std::bidirectional_iterator_tag;
  using value_type =
    typename std::remove_cv<typename std::remove_reference<decltype(
      std::declval<UnaryFunction>()(*std::declval<Iter>()))>::type>::type;
  using difference_type = typename std::iterator_traits<Iter>::difference_type;
  using pointer = value_type const*;
  using reference = value_type const&;

  TransformIterator(Iter i, UnaryFunction f)
    : Base(std::move(i))
    , Func(std::move(f))
  {
  }

  TransformIterator& operator++()
  {
    ++this->Base;
    return *this;
  }

  TransformIterator& operator--()
  {
    --this->Base;
    return *this;
  }

  bool operator==(TransformIterator const& other) const
  {
    return this->Base == other.Base;
  }

  bool operator!=(TransformIterator const& other) const
  {
    return !this->operator==(other);
  }

  auto operator*() const
    -> decltype(std::declval<UnaryFunction>()(*std::declval<Iter>()))
  {
    return this->Func(*this->Base);
  }

private:
  Iter Base;
  UnaryFunction Func;
};

} // namespace RangeIterators

template <typename Iter>
class cmRange
{
public:
  using const_iterator = Iter;
  using value_type = typename std::iterator_traits<Iter>::value_type;
  using difference_type = typename std::iterator_traits<Iter>::difference_type;

  cmRange(Iter b, Iter e)
    : Begin(std::move(b))
    , End(std::move(e))
  {
  }

  Iter begin() const { return this->Begin; }
  Iter end() const { return this->End; }
  bool empty() const { return this->Begin == this->End; }

  difference_type size() const
  {
    return std::distance(this->Begin, this->End);
  }

  cmRange& advance(difference_type amount) &
  {
    std::advance(this->Begin, amount);
    return *this;
  }

  cmRange advance(difference_type amount) &&
  {
    std::advance(this->Begin, amount);
    return std::move(*this);
  }

  cmRange& retreat(difference_type amount) &
  {
    std::advance(this->End, -amount);
    return *this;
  }

  cmRange retreat(difference_type amount) &&
  {
    std::advance(this->End, -amount);
    return std::move(*this);
  }

  template <typename UnaryPredicate>
  bool all_of(UnaryPredicate p) const
  {
    return std::all_of(this->Begin, this->End, std::ref(p));
  }

  template <typename UnaryPredicate>
  bool any_of(UnaryPredicate p) const
  {
    return std::any_of(this->Begin, this->End, std::ref(p));
  }

  template <typename UnaryPredicate>
  bool none_of(UnaryPredicate p) const
  {
    return std::none_of(this->Begin, this->End, std::ref(p));
  }

  template <typename UnaryPredicate>
  auto filter(UnaryPredicate p) const
    -> cmRange<RangeIterators::FilterIterator<Iter, UnaryPredicate>>
  {
    using It = RangeIterators::FilterIterator<Iter, UnaryPredicate>;
    return { It(this->Begin, this->End, p), It(this->End, this->End, p) };
  }

  template <typename UnaryFunction>
  auto transform(UnaryFunction f) const
    -> cmRange<RangeIterators::TransformIterator<Iter, UnaryFunction>>
  {
    using It = RangeIterators::TransformIterator<Iter, UnaryFunction>;
    return { It(this->Begin, f), It(this->End, f) };
  }

private:
  Iter Begin;
  Iter End;
};

template <typename Iter1, typename Iter2>
bool operator==(cmRange<Iter1> const& left, cmRange<Iter2> const& right)
{
  return left.size() == right.size() &&
    std::equal(left.begin(), left.end(), right.begin());
}

template <typename Iter1, typename Iter2>
auto cmMakeRange(Iter1 begin, Iter2 end) -> cmRange<Iter1>
{
  return { begin, end };
}

template <typename Range>
auto cmMakeRange(Range const& range) -> cmRange<decltype(range.begin())>
{
  return { range.begin(), range.end() };
}

template <typename Range>
auto cmReverseRange(Range const& range) -> cmRange<decltype(range.rbegin())>
{
  return { range.rbegin(), range.rend() };
}