LALRPOP's error recovery logic only allows it to recover from errors originating in LALRPOP.
So, if the lexer returns an error (say because a user typed '%', an unknown symbol in Slice) we would be incapable of recovering from it.
Instead, we should add an extra 'error' token to the lexers, and return Ok(error_token) to signal a lexer error, rather than Err(...). This will allow LALRPOP to gracefully recover from such lexer failures.
LALRPOP's error recovery logic only allows it to recover from errors originating in LALRPOP. So, if the lexer returns an error (say because a user typed '%', an unknown symbol in Slice) we would be incapable of recovering from it.
Instead, we should add an extra 'error' token to the lexers, and return
Ok(error_token)to signal a lexer error, rather thanErr(...). This will allow LALRPOP to gracefully recover from such lexer failures.