TL;TR

The objective of this exercise is to detect the repetition of a certain token, I am trying to do it with the symbol * coming from Regex, but it does not work.

Problem description

I am doing a basic transpiler, it consists in translating certain syntax with already defined grammar. I still have some drawbacks when defining the detection of multiple tokens. That is, using * to specify the repetition of a regex token (I think the * is used to define the repetition of a token), for example (see SENTENCE*):

 FUNCTION
   : DEF ID PAR_OPEN PAR_CLOSE
       SENTENCE*
     END
        { $$ = 'function ' + $2 + '(){' + $5 + '}' };

  SENTENCE
    : PRINT
    | VAR_ASSIGN
    |;

Grammar works with the input:

def hello() println "dsasd" end

but it does not work with the entry:

def hello() a = 3 println "dsasd" end

The error thrown is:

bash Error: Parse error on line 3: ...llo() a = 3 println "dsasd"end ---------------------^ Expecting 'EOF', '+', 'OR', 'AND', '=', '<>', '-', '*', '/', '>', '<', '>=', '<=','^', 'PAR_CLOSE', '%', 'END', got 'PRINTLN'

Could you tell me what I'm doing wrong?

See Gist complete code

Solved by adding %ebnf to the grammar. See here