impl/EquationSystem.g


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

grammar EquationSystem;

options {
  language=C;
  output=AST;
}

tokens {
  SYSTEM = 'system' ;
  PLUS = '+' ;
  SUB = '-' ;
  MULT = '*' ;
  MAXIMUM = 'max' ;
  MINIMUM = 'min' ;
  NEWLINE = '\n' ;
}

equation_system : equation ( NEWLINE! + equation  )* (NEWLINE!) *;
equation : VARIABLE '='! maxExpr;

maxExpr : MAXIMUM^ '('! minExpr ( ','! minExpr )* ')'! | minExpr;
minExpr : MINIMUM^ '('! maxExpr ( ','! maxExpr )* ')'! | expr ;

expr : term ( (PLUS | MULT | SUB)^ term )* ;

term : NUMBER | VARIABLE ;


NUMBER : (DIGIT)+ ;
VARIABLE: (LETTER) (LETTER | DIGIT)* ;
WHITESPACE : ( '\t' | ' ' | '\u000C' )+
             {
               $channel = HIDDEN;
             } ;

fragment
DIGIT : '0' .. '9' ;
fragment
LETTER: 'a' .. 'z' ;