This crate builds on the interfaces from [yap] to allow simple parsing of streams.

Why

There already exist many crates that intend to help with parsing. Of that list nom, winnow, chumsky, combine support parsing streams of values.

nom and winnow are very similar and share a few problems:

No obvious way to signal the end of a stream to a parser.
Running out of input requires re-parsing from scratch and redoing work.
The user of the library has to implement a streaming parser noticeably differently from a non-streaming parser.

chumsky is not designed for speed.

combine is complicated.

This crate allows using an already written [yap] parser by simply changing the initial tokens declaration.

# #[cfg(feature = "alloc")] {
use yap_streaming::{IntoTokens, StreamTokens, Tokens};
fn hello_world(tokens: &mut impl Tokens<Item = char>) -> Option<&'static str> {
    if tokens.tokens("hello".chars()) {
        tokens.skip_tokens_while(|c| c.is_whitespace());
        if tokens.tokens("world".chars()) {
            Some("hello world")
        } else {
            Some("hello")
        }
    } else {
        if tokens.tokens("world".chars()) {
            Some("world")
        } else {
            None
        }
    }
}
let msg = "hello world";
assert_eq!(hello_world(&mut msg.into_tokens()), hello_world(&mut StreamTokens::into_tokens(msg.chars())));
let msg = " world";
assert_eq!(hello_world(&mut msg.into_tokens()), hello_world(&mut StreamTokens::into_tokens(msg.chars())));
let msg = "world";
assert_eq!(hello_world(&mut msg.into_tokens()), hello_world(&mut StreamTokens::into_tokens(msg.chars())));
let msg = "";
assert_eq!(hello_world(&mut msg.into_tokens()), hello_world(&mut StreamTokens::into_tokens(msg.chars())));
# }

However, it can also use that parser on a stream of values that are not all in memory.

yap_streaming 0.1.0

Why