Question

can someone help me here, i am in stuck with this:

primaryExprList ('|'^ primaryExprList)*

I want to make it instead of ‘|’ to use BOOLEANOR

comment for Vojislav Stojkovic:

I have tried it but it wont work correctly when i use a|b|c it should be like this

    BOOLEANOR
      |        \
BOOLEANOR        c
|      |
a      b

and your soultion is like this:

       BOOLEANOR
   /       |      \
  a        b       c

which is not coorect.

Answer 1

I don’t really see the need. If you define a BOOLEANOR token (lexer rule):

parse     : primaryExprList ('|'^ primaryExprList)*;
// or:      primaryExprList (BOOLEANOR^ primaryExprList)*

BOOLEANOR : '|';

then the type of the root with be BOOLEANOR and its inner text is "|".

But, to answer your question (or propose a solution), the way to really change the root, is by using a rewrite rule like this:

grammar T;

options {
  output=AST;
}

tokens {
  OTHER;
}

parse
 : expr EOF!
 ;

expr
 : (e1=primaryExprList -> $e1) ('|' e2=primaryExprList -> ^(OTHER $expr $e2))*
 ;

// other rules

which will parse the input: “a|b|c” into the following AST: