C# Antlr: is there a way to have aliasses be generated as array when used inside *?-CodePudding

I'm using nuget package Antlr4.Runtime.Standard v4.11.1 in .NET 6 and have this grammar rule:

term : factor ( op = ( PLUS | MINUS ) factor )* ;

Note that alias op is inside the *. PLUS and MINUS are defined as ' ' and '-'

But, when i put this in the parser and my custom visitor:

1 2-3

... the generated context in my visitor gives me factor as an array of 3, but op as a single field, containing only the last occurrence '-'.

So, is there a way to get all occurrences of that op, somehow? Or do I have to process rules like this by walking the children array, and finding out what is what myself?

thanks

CodePudding user response：

The in ANTLR just (re) assigns the token to op. To collect all tokens, you can do =:

term
 : factor ( op =( PLUS | MINUS ) factor )* 
 ;

where op will now be a list of tokens. Or just don't use * at all:

term
 : factor ( ( PLUS | MINUS ) term )?
 ;

in which case you'll always have only 1 expression to evaluate (if PLUS or MINUS is present).