pattern

A compact pattern recognition and extraction system.

no_std

This crate is intended for use in no_std environments.

Usage

Given an iterator of some serialized data, values of various types can be extracted in sequence.

fn get_from_data(data: &mut &[u8]) -> Result<(u8, u16, u16, u32), PatternError> {
    let mut pattern = Pattern::new(data.iter());

    let [start] = pattern
        .values([0u8, 1u8]) // look for these exact values in order
        .deferred() // eat bytes until these values are found
        .extract()?; // attempt extraction

    let [a] = pattern
        .get() // deserialize 1 expected type from u8's (.get() only supports u8's)
        .extract()?;

    let [b, c] = pattern
        .get() // deserialize 2 of the expected type (u16)
        .extract_and(|bytes| { /* do something with the bytes */ })?; // attempt extraction then call closure on bytes extracted

    let [d] = pattern
        .get() // deserialize 1 expected type (u32)
        .extract()?;

    Ok((a, b, c, d))
}

Dependencies

This crate uses the tiny-serde crate for deserialization.

defmt is available behind a feature gate for formatting PatternError.

Design Considerations

Safety

This crate does use unsafe blocks but has been proven to never exhibit undefined behavior.