jaypha.container.stack source code

1 //Written in the D programming language
2 /*
3  * Simple stack.
4  *
5  * Copyright (C) 2014 Jaypha
6  *
7  * Distributed under the Boost Software License, Version 1.0.
8  * (See http://www.boost.org/LICENSE_1_0.txt)
9  *
10  * Authors: Jason den Dulk
11  */
12 
13 module jaypha.container.stack;
14 
15 import std.array;
16 
17 struct Stack(E)
18 {
19   private:
20 
21     E[] q;
22 
23   public:
24 
25     void put(E e)
26     {
27       q ~= e;
28     }
29 
30     @property bool empty() { return q.empty; }
31     @property ref E front() { return q[$-1]; }
32     void popFront() { q = q[0..$-1]; }
33 
34     void clear() { q.length = 0; }
35 }
36 
37 unittest
38 {
39   Stack!long stack;
40 
41   assert(stack.empty);
42 
43   stack.put(5);
44 
45   assert(!stack.empty);
46   assert(stack.front == 5);
47 
48   stack.put(12);
49 
50   assert(!stack.empty);
51   assert(stack.front == 12);
52 
53   stack.popFront();
54 
55   assert(!stack.empty);
56   assert(stack.front == 5);
57 
58   stack.put(3);
59 
60   assert(!stack.empty);
61   assert(stack.front == 3);
62 
63   stack.popFront();
64 
65   assert(!stack.empty);
66   assert(stack.front == 5);
67   
68   stack.popFront();
69 
70   assert(stack.empty);
71 
72   stack.put(3);
73   stack.put(12);
74 
75   assert(!stack.empty);
76   assert(stack.front == 12);
77 
78   stack.clear();
79   assert(stack.empty);
80 }