async-utf8-decoder

Incremental UTF8 decoder which convert [AsyncRead][] into [Stream][] of futures-rs.

Example

```rust use anyhow::Result; use asyncstd::io::Cursor; use asyncstd::future::timeout; use asyncstd::prelude::*; use std::time::Duration; use asyncutf8_decoder::Utf8Decoder;

async fn test() -> Result<()> { let dur = Duration::from_millis(10); let cur = Cursor::new(Vec::new()); let mut decoder = Utf8Decoder::new(cur);

async fn append(cursor: &mut Cursor<Vec<u8>>, data: &[u8]) -> Result<()> {
    let p = cursor.position();
    cursor.set_position(cursor.get_ref().len() as u64);
    cursor.write(data).await?;
    cursor.set_position(p);
    Ok(())
}

// Decode full
append(decoder.get_mut(), &vec![240, 159, 146, 150]).await?;
let decoded = timeout(dur, decoder.next()).await?.unwrap()?;
assert_eq!("💖", decoded);

// Decode half
append(decoder.get_mut(), &vec![240, 159]).await?;
assert!(timeout(dur, decoder.next()).await.is_err());
append(decoder.get_mut(), &vec![146, 150]).await?;
let decoded = timeout(dur, decoder.next()).await?.unwrap()?;
assert_eq!("💖", decoded);

// Decode char
append(decoder.get_mut(), &vec![240]).await?;
assert!(timeout(dur, decoder.next()).await.is_err());
append(decoder.get_mut(), &vec![159]).await?;
assert!(timeout(dur, decoder.next()).await.is_err());
append(decoder.get_mut(), &vec![146]).await?;
assert!(timeout(dur, decoder.next()).await.is_err());
append(decoder.get_mut(), &vec![150]).await?;
let decoded = timeout(dur, decoder.next()).await?.unwrap()?;
assert_eq!("💖", decoded);

// Decode lot
append(
    decoder.get_mut(),
    &vec![
        240, 159, 146, 150, 240, 159, 146, 150, 240, 159, 146, 150, 240, 159, 146, 150,
        240, 159, 146, 150,
    ],
)
.await?;
let decoded = timeout(dur, decoder.next()).await?.unwrap()?;
assert_eq!("💖💖💖💖💖", decoded);

Ok(())

} ```

License

The code follows MIT license written in LICENSE. Contributors need to agree that any modifications sent in this repository follow the license.