spec.jj

options {
    LOOKAHEAD = 1;
    CHOICE_AMBIGUITY_CHECK = 2;
    OTHER_AMBIGUITY_CHECK = 1;
    STATIC = true;
    DEBUG_PARSER = false;
    DEBUG_LOOKAHEAD = false;
    DEBUG_TOKEN_MANAGER = false;
    ERROR_REPORTING = true;
    JAVA_UNICODE_ESCAPE = false;
    UNICODE_INPUT = false;
    IGNORE_CASE = false;
    USER_TOKEN_MANAGER = false;
    USER_CHAR_STREAM = false;
    BUILD_PARSER = true;
    BUILD_TOKEN_MANAGER = true;
    SANITY_CHECK = true;
    FORCE_LA_CHECK = false;
    OUTPUT_DIRECTORY = "src/io/elcapitan/parserGen";
}

PARSER_BEGIN(ExampleParser)

package genParser;

public class ExampleParser {
   public static void main(String[] args) throws ParseException {
       ExampleParser parser = new ExampleParser(System.in);
       boolean solution = parser.exp();
       System.out.println(solution);
   }
}

PARSER_END(ExampleParser)

boolean exp():
{
 char cmpOp;
 char op;
 int comp;
 int numLeft;
 int numRight;

 boolean bool;
 boolean fi;
 boolean fiReturn;
 boolean elseReturn;
}
{
    "i" fi=exp() "t" fiReturn=exp() "e" elseReturn=exp() "f"
    {
        if (fi) return fiReturn;
        else return elseReturn;
    }
    | "2" cmpOp=cmp() comp=aexp()
    {
        if (cmpOp == '>') return 2 > comp;
        else if(cmpOp == '<') return 2 < comp;
        else return 2 == comp;
    }
    | "3" cmpOp=cmp() comp=aexp()
    {
            if (cmpOp == '>') return 3 > comp;
            else if(cmpOp == '<') return 3 < comp;
            else return 3 == comp;
    }
    | "4" cmpOp=cmp() comp=aexp()
    {
            if (cmpOp == '>') return 4 > comp;
            else if(cmpOp == '<') return 4 < comp;
            else return 4 == comp;
    }
    | ":" numLeft=aexp() op=op() numRight=aexp() ";" cmpOp=cmp() comp=aexp()
    {
        int solution;
        if (op == '+') solution = numLeft + numRight;
        else solution = numLeft - numRight;

        if (cmpOp == '>') return solution > comp;
        else if(cmpOp == '<') return solution < comp;
        else return solution == comp;
    }
    | "n" bool=exp() {return !bool;}
    | "0" {return false;}
    | "1" {return true;}
}

int aexp() :
{
 int numLeft;
 int numRight;
 char op;
}
{
    "2" {return 2;} | "3" {return 3;} | "4" {return 4;}
    | ":" numLeft=aexp() op=op() numRight=aexp() ";"
    {
        if(op == '+') return numLeft + numRight;
        else return numLeft - numRight;
    }
}

char cmp() :
{}
{
    "<" {return '<';} | ">" {return '>';} | "=" {return '=';}
}

char op() :
{}
{
    "+" {return '+';} | "-" {return '-';}
}