PreferredRules Question: Candidate rules miss some preferred rules.

[vczyh]

I don't know if it's a BUG.

Example1 results only contain functionRef, Example2 contain functionRef and variableRef.

Example code is here: https://github.com/vczyh/antlr-c3-maybe-bug-examples

Completion

const inputStream = CharStream.fromString("a.b");

core.preferredRules = new Set([
  ExprParser.RULE_variableRef,
  ExprParser.RULE_functionRef,
]);

const candidates = core.collectCandidates(2);

Example1

Expr.g4

grammar Expr;

expression:
    variableRef
    | functionRef
;

variableRef: identifier dotIdentifier;

functionRef: identifier dotIdentifier OPEN_PAR CLOSE_PAR;

identifier: ID;

dotIdentifier: DOT identifier;

OPEN_PAR:  '(';
CLOSE_PAR: ')';
DOT:      '.';
ID:        [a-zA-Z] [a-zA-Z0-9_]*;
WS:        [ \n\r\t] -> channel(HIDDEN);

Result:

This is example1.
States processed: 17


Collected rules:

functionRef, path:  expression 


Collected tokens:




CandidatesCollection {
  tokens: Map(0) {},
  rules: Map(1) { 2 => { startTokenIndex: 0, ruleList: [Array] } }
}

Example2

Expr.g4

grammar Expr;

expression:
    variableRef
    | functionRef
;

variableRef: identifier DOT identifier;

functionRef: identifier dotIdentifier OPEN_PAR CLOSE_PAR;

identifier: ID;

dotIdentifier: DOT identifier;

OPEN_PAR:  '(';
CLOSE_PAR: ')';
DOT:      '.';
ID:        [a-zA-Z] [a-zA-Z0-9_]*;
WS:        [ \n\r\t] -> channel(HIDDEN);

Result:

This is example2.
States processed: 18


Collected rules:

functionRef, path:  expression 
variableRef, path:  expression 


Collected tokens:




CandidatesCollection {
  tokens: Map(0) {},
  rules: Map(2) {
    2 => { startTokenIndex: 0, ruleList: [Array] },
    1 => { startTokenIndex: 0, ruleList: [Array] }
  }
}

Thanks.