blob: 9117c280d4310f89b7e9e785249bdeeacb533eff (
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
|
import std.stdio;
import std.string;
import std.conv;
import std.typecons;
import std.container : SList;
import std.container : DList;
SList!int stack;
DList!string[string] words;
Nullable!(DList!string) definition;
void startDefinition()
in { assert( definition.isNull); }
out { assert(!definition.isNull); }
body {
definition = DList!string();
}
void endDefinition()
in { assert(!definition.isNull); }
out { assert( definition.isNull); }
body {
auto wordToBeDefined = definition.front;
if ( wordToBeDefined.isNumeric ) {
throw new Exception("words may not be numeric");
} else {
definition.removeFront;
words[wordToBeDefined] = definition;
definition.nullify;
}
}
void append(ref Nullable!(DList!string) definition, string token) {
if ( token == ";" ) {
endDefinition();
} else {
definition.insertBack(token);
}
}
void evaluate(string word) {
switch ( word ) {
case "ยง":
startDefinition();
break;
case "+":
auto a = stack.pop();
auto b = stack.pop();
stack.push(a + b);
break;
case "*":
auto a = stack.pop();
auto b = stack.pop();
stack.push(a * b);
break;
case ".":
writeln(stack.front);
break;
default:
foreach ( token; words[word] ) {
process(token);
}
}
}
void process(string token) {
if ( token.isNumeric ) {
stack.push(parse!int(token));
} else {
evaluate(token);
}
}
void push(ref SList!int stack, int value) {
if ( definition.isNull ) {
stack.insertFront(value);
} else {
definition.append(to!string(value));
}
}
int pop(ref SList!int stack) {
auto x = stack.front;
stack.removeFront;
return x;
}
void main() {
while ( !stdin.eof ) {
foreach ( token; stdin.readln.split ) {
if ( definition.isNull ) {
process(token);
} else {
definition.append(token);
}
}
}
}
|
