comtains

comtains expands static byte sequences into zero-allocation matchers at compile time. The byte_set! macro emits a branch-ordered decision tree, keeping membership checks to a handful of predictable instructions—ideal for tight opcode dispatchers or protocol parsers.

use comtains::{byte_set, ByteSet};

const HTTP_METHODS: ByteSet = byte_set![b"GET", b"POST", b"PUT", b"PATCH"];

assert!(HTTP_METHODS.contains(b"GET"));
assert!(!HTTP_METHODS.contains(b"DELETE"));

How it works

1. All inputs are parsed at macro expansion time into a trie that shares common prefixes.
2. Each edge records how many sequences traverse it; siblings are sorted by descending weight to probe common paths first.
3. The macro generates a nested match ladder that compares candidate[depth], short-circuiting on the first mismatch.
4. Debug metadata is emitted alongside the matcher so tests and benchmarks can assert branch ordering or inspect the trie layout.