How can I set the context for collecting candidates about antlr4-c3 HOT 2 CLOSED

Such a context becomes available when you parsed the input. Contexts are created during that run and freed when a new parse run starts (unless you keep a reference somewhere, but that can lead to trouble if the underlying token stream changed, so better don't do that).

Once you got the full parse tree (e.g. from a syntax check) you can then search for a particular sub context (a specific context type or by position or something else).

However, in your case I would use a different strategy: when you construct your completion items list from the candidates you can check if that is something you don't want the user to add, so simply don't include that specific item in your final list.

from antlr4-c3.

Thanks for your explanation, looks like this does the trick

 const tree = parser[context]()
 const { rules, tokens } = core.collectCandidates(cursorPosition, tree)

from antlr4-c3.