Look ahead / peek?

[jayhale]

Hello! I'm working on an SQL parser and would like to improve the approach I've taken to qualifying certain tokens. Specifically, I'd like to have some rules that look-ahead in order to match the current rule (a forward predicate).

Is there an approach to doing this in Pest?

E.g., something like below, which does not work:

select_key_word = { ^"SELECT" ~ &delimiter }

That is to say "SELECT" is a keyword when it is followed by a delimiter, otherwise it might be something else (an identifier in SQL). I want to check for the delimiter while leaving it to be matched by the next rule (most likely WHITESPACE).

Is there a way to do this?

[Tartasprint]

What is not working ? I tried this on the online editor.

It should work.