// -*- sugar -*-
        
// white = '\009' | '\011' | '\012' | '\032';
// comment = '//';
// newline = '\013' | '\010' | '\013\010';
// 
// digit = '0'-'9';
// int = digit+;
// letter = 'A'-'Z' | 'a'-'z';
// alpha = letter | digit | '_';
// id = letter alpha*;
// literal = '\'' -- '\'';
// str = '\"' -- '\"';


grammar: rule+;

rule:
= Alias: id ':' item+ ';'
| Union: id ':' group+ ';'
;

assoc:
= Non: '='
| Left: '<'
| Right: '>'
;

group: assoc case ++ '|';
case: id ':' item*;


item:
= Literal: literal
| Id: id
| Mark: literal '?'
| Option: id '?'
| Star: id '*'
| Plus: id '+'
| Sstar: id '**' literal
| Pplus: id '++' literal
;