aboutsummaryrefslogtreecommitdiff
path: root/libbuild2/functions-integer.cxx
blob: ddfc250590085c43fdfdb5c6df5b5630038e13e7 (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
// file      : libbuild2/functions-integer.cxx -*- C++ -*-
// license   : MIT; see accompanying LICENSE file

#include <libbuild2/function.hxx>
#include <libbuild2/variable.hxx>

using namespace std;

namespace build2
{
  extern bool
  functions_sort_flags (optional<names>); // functions-builtin.cxx

  static const char hex_digits[] = "0123456789abcdef";

  static string
  to_string (uint64_t i, optional<value> base, optional<value> width)
  {
    uint64_t b (base ? convert<uint64_t> (move (*base)) : 10);
    size_t w (width
              ? static_cast<size_t> (convert<uint64_t> (move (*width)))
              : 0);

    // One day we can switch to C++17 std::to_chars().
    //
    string r;
    switch (b)
    {
    case 10:
      {
        r = to_string (i);
        if (w > r.size ())
          r.insert (0, w - r.size (), '0');
        break;
      }
    case 16:
      {
        r.reserve (18);
        r += "0x";

        for (size_t j (64); j != 0; )
        {
          j -= 4;
          size_t d ((i >> j) & 0x0f);

          // Omit leading zeros but watch out for the i==0 corner case.
          //
          if (d != 0 || r.size () != 2 || j == 0)
            r += hex_digits[d];
        }

        if (w > r.size () - 2)
          r.insert (2, w - (r.size () - 2), '0');

        break;
      }
    default:
      throw invalid_argument ("unsupported base");
    }

    return r;
  }

  void
  integer_functions (function_map& m)
  {
    function_family f (m, "integer");

    // $string(<int64>)
    // $string(<uint64>[, <base>[, <width>]])
    //
    f["string"] += [](int64_t i) {return to_string (i);};

    f["string"] += [](uint64_t i, optional<value> base, optional<value> width)
    {
      return to_string (i, move (base), move (width));
    };

    // $integer_sequence(<begin>, <end>[, <step>])
    //
    // Return the list of uint64 integers starting from <begin> (including) to
    // <end> (excluding) with the specified <step> or 1 if unspecified. If
    // <begin> is greater than <end>, empty list is returned.
    //
    // Note that currently negative numbers are not supported but this could
    // be handled if required (e.g., by returning int64s in this case).
    //
    // Note also that we could improve this by adding a shortcut to get the
    // indexes of a list (for example, $indexes(<list>) plus potentially a
    // similar $keys() function for maps).
    //
    f["integer_sequence"] += [](value begin, value end, optional<value> step)
    {
      uint64_t b (convert<uint64_t> (move (begin)));
      uint64_t e (convert<uint64_t> (move (end)));
      uint64_t s (step ? convert<uint64_t> (move (*step)) : 1);

      uint64s r;
      if (b < e)
      {
        r.reserve (static_cast<size_t> ((e - b) / s + 1));

        for (; b < e; b += s)
          r.push_back (static_cast<size_t> (b));
      }

      return r;
    };

    // $size(<ints>)
    //
    // Return the number of elements in the sequence.
    //
    f["size"] += [] (int64s v) {return v.size ();};
    f["size"] += [] (uint64s v) {return v.size ();};

    // $sort(<ints> [, <flags>])
    //
    // Sort integers in ascending order.
    //
    // The following flags are supported:
    //
    //   dedup - in addition to sorting also remove duplicates
    //
    f["sort"] += [](int64s v, optional<names> fs)
    {
      sort (v.begin (), v.end ());

      if (functions_sort_flags (move (fs)))
        v.erase (unique (v.begin(), v.end()), v.end ());

      return v;
    };

    f["sort"] += [](uint64s v, optional<names> fs)
    {
      sort (v.begin (), v.end ());

      if (functions_sort_flags (move (fs)))
        v.erase (unique (v.begin(), v.end()), v.end ());

      return v;
    };

    // $find(<ints>, <int>)
    //
    // Return true if the integer sequence contains the specified integer.
    //
    f["find"] += [](int64s vs, value v)
    {
      return find (vs.begin (), vs.end (),
                   convert<int64_t> (move (v))) != vs.end ();
    };

    f["find"] += [](uint64s vs, value v)
    {
      return find (vs.begin (), vs.end (),
                   convert<uint64_t> (move (v))) != vs.end ();
    };

    // $find_index(<ints>, <int>)
    //
    // Return the index of the first element in the integer sequence that is
    // equal to the specified integer or $size(<ints>) if none is found.
    //
    f["find_index"] += [](int64s vs, value v)
    {
      auto i (find (vs.begin (), vs.end (), convert<int64_t> (move (v))));
      return i != vs.end () ? i - vs.begin () : vs.size ();
    };

    f["find_index"] += [](uint64s vs, value v)
    {
      auto i (find (vs.begin (), vs.end (), convert<uint64_t> (move (v))));
      return i != vs.end () ? i - vs.begin () : vs.size ();
    };
  }
}