1grammar t015calc;
2options {
3  language = Python3;
4}
5
6@header {
7import math
8}
9
10@parser::init {
11self.reportedErrors = []
12}
13
14@parser::members {
15def emitErrorMessage(self, msg):
16    self.reportedErrors.append(msg)
17}
18
19evaluate returns [result]: r=expression {result = r};
20
21expression returns [result]: r=mult (
22    '+' r2=mult {r += r2}
23  | '-' r2=mult {r -= r2}
24  )* {result = r};
25
26mult returns [result]: r=log (
27    '*' r2=log {r *= r2}
28  | '/' r2=log {r /= r2}
29//  | '%' r2=log {r %= r2}
30  )* {result = r};
31
32log returns [result]: 'ln' r=exp {result = math.log(r)}
33    | r=exp {result = r}
34    ;
35
36exp returns [result]: r=atom ('^' r2=atom {r = math.pow(r,r2)} )? {result = r}
37    ;
38
39atom returns [result]:
40    n=INTEGER {result = int($n.text)}
41  | n=DECIMAL {result = float($n.text)}
42  | '(' r=expression {result = r} ')'
43  | 'PI' {result = math.pi}
44  | 'E' {result = math.e}
45  ;
46
47INTEGER: DIGIT+;
48
49DECIMAL: DIGIT+ '.' DIGIT+;
50
51fragment
52DIGIT: '0'..'9';
53
54WS: (' ' | '\n' | '\t')+ {$channel = HIDDEN};
55