Function until 

pub(crate) fn until<P: Peek, R>(
    cx: &mut ParseCtxt<'_>,
    end: P,
    parse: impl FnMut(&mut ParseCtxt<'_>) -> ParseResult<R>,
) -> ParseResult<Vec<R>>

Parses a list of zero or more items. Parsing continues until the requested end token is reached. This does not consume the end token.