Recognize a token that matches a [set of tokens][ContainsToken]

Complete version: Will return an error if there's not enough input data.

[Partial version][crate::_topic::partial]: Will return Err(winnow::error::ErrMode::Incomplete(_)) if there's not enough input data.

Effective Signature

Assuming you are parsing a &str [Stream]:

# use winnow::prelude::*;;
# use winnow::stream::ContainsToken;
# use winnow::error::ContextError;
pub fn one_of<'i>(set: impl ContainsToken<char>) -> impl Parser<&'i str, char, ContextError>
# {
#     winnow::token::one_of(set)
# }

Example

# use winnow::prelude::*;
# use winnow::{error::ErrMode, error::ContextError};
# use winnow::token::one_of;
assert_eq!(one_of::<_, _, ContextError>(['a', 'b', 'c']).parse_peek("b"), Ok(("", 'b')));
assert!(one_of::<_, _, ContextError>('a').parse_peek("bc").is_err());
assert!(one_of::<_, _, ContextError>('a').parse_peek("").is_err());

fn parser_fn(i: &mut &str) -> ModalResult<char> {
    one_of(|c| c == 'a' || c == 'b').parse_next(i)
}
assert_eq!(parser_fn.parse_peek("abc"), Ok(("bc", 'a')));
assert!(parser_fn.parse_peek("cd").is_err());
assert!(parser_fn.parse_peek("").is_err());

# use winnow::prelude::*;
# use winnow::{error::ErrMode, error::ContextError, error::Needed};
# use winnow::Partial;
# use winnow::token::one_of;
assert_eq!(one_of::<_, _, ErrMode<ContextError>>(['a', 'b', 'c']).parse_peek(Partial::new("b")), Ok((Partial::new(""), 'b')));
assert!(one_of::<_, _, ErrMode<ContextError>>('a').parse_peek(Partial::new("bc")).is_err());
assert_eq!(one_of::<_, _, ErrMode<ContextError>>('a').parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::new(1))));

fn parser_fn(i: &mut Partial<&str>) -> ModalResult<char> {
    one_of(|c| c == 'a' || c == 'b').parse_next(i)
}
assert_eq!(parser_fn.parse_peek(Partial::new("abc")), Ok((Partial::new("bc"), 'a')));
assert!(parser_fn.parse_peek(Partial::new("cd")).is_err());
assert_eq!(parser_fn.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::new(1))));