newline with scope block

[Neo]

Hi all.

I have following grammar:

WS: (' ' | '\t') -> skip;
NEWLINE: [\n]+;

prog: instList? EOF;
instList: (instr NEWLINE+)+;
operator1: 'op1';
operator2: 'op2';
blockOperator: 'block';
instr: Identifier (operator1 | operator2) Identifier
      | blockOperator '{' instList? '}'
;

Examples of my language:
a op1 b
c op2 a
block {
    d op2 a
    a op1 b
    ...
}

block {} // also allowed

But Antlr doesn't handle block greedy. It consider that

blockOperator '{' instList? '}'

instList is empty and add missing on '}'.

Any suggestion?