I'm trying to port a parser written with nom in Rust to a C# parser with Pidgin. There are some cases where I need the result of a terminator from AtLeastOnceUntil. With nom, I can extract both the first result, and the terminator like so

let (input, (title, version)) = take_up_to(
        alt((
            preceded(char(' '), parse_version_string).map(|t| Some(t)),
            peek(alt((char('('), char('[')))).map(|_| None)))
    )(input)?;

Somewhat equivalently I've written up this parser with Pidgin

from title in Any.AtLeastOnceUntil(Lookahead(
           Try(Char(' ').Before(ParseVersionString)).Or(
               Try(Char('(').Or(Char('[')))))).Select(string.Concat)
from version in Char(' ').Then(ParseVersionString).Optional()
select (title, version.Match(v => new RomTag[] { v }, () => Enumerable.Empty<RomTag>()));

While both of the terminator parsers have to run O(t) iterations where t is the length of title, it doesn't need to re-parse the version in the Rust version. Is it possible to achieve this with Pidgin or is this pretty much the best way to do it?