Halfling

A library of basic utilities for working with nibbles, representing both raw data (halfling::nibble::Nibble) and integral values (halfling::integer::{I4, U4}).

Typical usage of this crate would be to reexport one of these principal types as part of a public API, though we encourage wrapping these in newtypes while halfling is still pre-v1.0.0; in particular the delegate crate is useful for this purpose.

Performance

The principal types Nibble, I4, and U4 should operate as (almost) zero-cost wrappers over the integral-byte types u8 and i8, and egregious outliers are considered bugs; we encourage you to file an issue if you see this behaviour!

The notable exception is bitwise operations on I4s, since they're backed by i8s which first need to be transformed into a 4-bit two's complement representation; this compromise is based on the assumption that the integral types ought to focus on fast arithmetic operations.

Roadmap

• v0.2.0
  • Checked, saturating, and wrapping operation impls for U4 and I4
  • Binary operations with primitive types (u8 and i8) for U4 and I4