libd.algorithm.mutate source code

1 module libd.algorithm.mutate;
2 
3 auto map(alias Mapper, RangeT)(RangeT range)
4 {
5     import libd.algorithm;
6 
7     alias ElementT = typeof(Mapper(range.front));
8     static struct Range
9     {
10         private RangeT _range;
11         private ElementT _front;
12         private bool _empty;
13 
14         @nogc nothrow:
15 
16         this(RangeT range)
17         {
18             this._range = range;
19             this.popFront();
20         }
21 
22         void popFront()
23         {
24             if(this._range.empty)
25             {
26                 this._empty = true;
27                 return;
28             }
29 
30             this._front = Mapper(this._range.front);
31             this._range.popFront();
32         }
33 
34         bool empty()
35         {
36             return this._empty;
37         }
38 
39         ElementT front()
40         {
41             return this._front;
42         }
43     }
44 
45     return Range(range);
46 }
47 ///
48 @("map")
49 unittest
50 {
51     import libd.data.conv, libd.algorithm;
52 
53     Array!int nums;
54     nums.put(1, 2, 3);
55 
56     String[3] expected = [String("1"), String("2"), String("3")];
57     auto range = nums.range.map!(n => n.to!String);
58     assert(range.equals!((a,b) => a == b)(expected[0..$]));
59 }