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