epsilon.soag.listacks source code

1 module epsilon.soag.listacks;
2 
3 import runtime;
4 
5 const emptyStack = -1;
6 const firstStackElem = 0;
7 alias DataType = long;
8 alias StackList = DataType[];
9 
10 struct Stack
11 {
12     int Top;
13     StackList Elem;
14 }
15 
16 void Expand(ref Stack S) nothrow pure @safe
17 {
18     StackList List1;
19 
20     if (S.Elem.length < DIV(int.max, 2))
21     {
22         List1 = new DataType[2 * S.Elem.length + 1];
23     }
24     else
25     {
26         assert(0);
27     }
28     for (size_t i = firstStackElem; i <= S.Top; ++i)
29     {
30         List1[i] = S.Elem[i];
31     }
32     S.Elem = List1;
33 }
34 
35 void New(ref Stack S, int Len) nothrow pure @safe
36 {
37     S = Stack();
38     S.Elem = new DataType[Len];
39     S.Top = emptyStack;
40 }
41 
42 void Reset(ref Stack S) @nogc nothrow pure @safe
43 {
44     S.Top = emptyStack;
45 }
46 
47 void Push(ref Stack S, DataType Val) nothrow pure @safe
48 {
49     if (S.Top + 2 >= S.Elem.length)
50         Expand(S);
51 
52     ++S.Top;
53     S.Elem[S.Top] = Val;
54 }
55 
56 void Pop(ref Stack S) @nogc nothrow pure @safe
57 {
58     --S.Top;
59 }
60 
61 DataType Top(ref Stack S) @nogc nothrow pure @safe
62 {
63     return S.Elem[S.Top];
64 }
65 
66 DataType TopPop(ref Stack S) @nogc nothrow pure @safe
67 {
68     DataType R;
69     R = S.Elem[S.Top];
70     --S.Top;
71     return R;
72 }
73 
74 bool IsEmpty(Stack S) @nogc nothrow pure @safe
75 {
76     return S.Top <= emptyStack;
77 }