1//===- Sequence.h - Utility for producing sequences of values ---*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9/// \file
10/// This routine provides some synthesis utilities to produce sequences of
11/// values. The names are intentionally kept very short as they tend to occur
12/// in common and widely used contexts.
13///
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_ADT_SEQUENCE_H
17#define LLVM_ADT_SEQUENCE_H
18
19#include "llvm/ADT/iterator.h"
20#include "llvm/ADT/iterator_range.h"
21#include <algorithm>
22#include <iterator>
23#include <utility>
24
25namespace llvm {
26
27namespace detail {
28
29template <typename ValueT>
30class value_sequence_iterator
31    : public iterator_facade_base<value_sequence_iterator<ValueT>,
32                                  std::random_access_iterator_tag,
33                                  const ValueT> {
34  using BaseT = typename value_sequence_iterator::iterator_facade_base;
35
36  ValueT Value;
37
38public:
39  using difference_type = typename BaseT::difference_type;
40  using reference = typename BaseT::reference;
41
42  value_sequence_iterator() = default;
43  value_sequence_iterator(const value_sequence_iterator &) = default;
44  value_sequence_iterator(value_sequence_iterator &&Arg)
45      : Value(std::move(Arg.Value)) {}
46
47  template <typename U, typename Enabler = decltype(ValueT(std::declval<U>()))>
48  value_sequence_iterator(U &&Value) : Value(std::forward<U>(Value)) {}
49
50  value_sequence_iterator &operator+=(difference_type N) {
51    Value += N;
52    return *this;
53  }
54  value_sequence_iterator &operator-=(difference_type N) {
55    Value -= N;
56    return *this;
57  }
58  using BaseT::operator-;
59  difference_type operator-(const value_sequence_iterator &RHS) const {
60    return Value - RHS.Value;
61  }
62
63  bool operator==(const value_sequence_iterator &RHS) const {
64    return Value == RHS.Value;
65  }
66  bool operator<(const value_sequence_iterator &RHS) const {
67    return Value < RHS.Value;
68  }
69
70  reference operator*() const { return Value; }
71};
72
73} // end namespace detail
74
75template <typename ValueT>
76iterator_range<detail::value_sequence_iterator<ValueT>> seq(ValueT Begin,
77                                                            ValueT End) {
78  return make_range(detail::value_sequence_iterator<ValueT>(Begin),
79                    detail::value_sequence_iterator<ValueT>(End));
80}
81
82} // end namespace llvm
83
84#endif // LLVM_ADT_SEQUENCE_H
85