Antlr4 left-recursive rule appears to produce right-associative parse - antlr4

Question

The following grammar illustrates the issue:
// test Antlr4 left recursion associativity
grammar LRA;
#parser::members {
public static void main(String[] ignored) throws Exception{
final LRALexer lexer = new LRALexer(new ANTLRInputStream(System.in));
final LRAParser parser = new LRAParser(new CommonTokenStream(lexer));
parser.setTrace(true);
parser.file();
}
}
ID: [A-Za-z_] ([A-Za-z_]|[0-9])*;
CMA: ',';
SMC: ';';
UNK: . -> skip;
file: punctuated EOF;
punctuated
: punctuated cma punctuated
| punctuated smc punctuated
| expression
;
cma: CMA;
smc: SMC;
expression: id;
id: ID;
Given input "a,b,c" i get listener event trace output
( 'a' ) ( ',' ( 'b' ) ( ',' ( 'c' ) ) )
where ( represents enter punctuated, ) represents exit punctuated, and all other rules are omitted for brevity and clarity.
By inspection, this order of listener events represents a right-associative parse.
Common practice, and The Definitive Antlr 4 Reference, lead me to expect a left-associative parse, corresponding to the following listener event trace
( 'a' ) ( ',' ( 'b' ) ) ( ',' ( 'c' ) )
Is there something wrong with my grammar, my expectations, my interpretation of the listener events, or something else?

Answer 1

I would consider the workaround described above to be an adequate answer. The generated parser needs to pass a precedence parameter to a recursive call, and since the precedence is associated with a token, the token has to be directly available in the recursive rule so Antlr can find its precedence.
The working grammar looks like this:
// test Antlr4 left recursion associativity
grammar LRA;
#parser::members {
public static void main(String[] ignored) throws Exception{
final LRALexer lexer = new LRALexer(new ANTLRInputStream(System.in));
final LRAParser parser = new LRAParser(new CommonTokenStream(lexer));
parser.setTrace(true);
parser.file();
}
}
ID: [A-Za-z_] ([A-Za-z_]|[0-9])*;
CMA: ',';
SMC: ';';
UNK: . -> skip;
file: punctuated EOF;
punctuated
: punctuated CMA punctuated
| punctuated SMC punctuated
| expression
;
expression: id;
id: ID;