skip Whitespace And Comments
Skip over whitespace and comment tokens, collecting the latter. Produce a List of ParserStates corresponding to the possible positions after completely parsing runs of whitespaces and comments (i.e., the potential A_Tokens that follow each such ParserState must include at least one token that isn't whitespace or a comment). Invoke the continuation with this list of parser states.
Informally, it just skips as many whitespace and comment tokens as it can, but the nature of the ambiguous lexer makes this more subtle to express.
Note that the continuation always gets invoked exactly once, after any relevant lexing has completed.
Parameters
start
Where to start consuming the token.
continuation
What to invoke with the collection of successor ParserStates.