Crate ferroni 

Ferroni

Pure-Rust regex engine based on Oniguruma, with SIMD-accelerated search via memchr.

Ferroni is a line-by-line port of Oniguruma’s C source into Rust – same structure, same function names, same semantics. No bindings, no FFI.

Quick Start

use ferroni::prelude::*;

let re = Regex::new(r"\d{4}-\d{2}-\d{2}").unwrap();
let m = re.find("Date: 2026-02-12").unwrap();
assert_eq!(m.as_str(), "2026-02-12");
assert_eq!(m.start(), 6);

For fine-grained control, use [RegexBuilder]:

use ferroni::prelude::*;

let re = Regex::builder(r"hello")
    .case_insensitive(true)
    .build()
    .unwrap();
assert!(re.is_match("Hello World"));

Low-Level C-Style API

The full C-ported API is also available for advanced usage:

use ferroni::regcomp::onig_new;
use ferroni::regexec::onig_search;
use ferroni::oniguruma::*;
use ferroni::regsyntax::OnigSyntaxOniguruma;

let reg = onig_new(
    b"\\d{4}-\\d{2}-\\d{2}",
    ONIG_OPTION_NONE,
    &ferroni::encodings::utf8::ONIG_ENCODING_UTF8,
    &OnigSyntaxOniguruma,
).unwrap();

let input = b"Date: 2026-02-12";
let (result, region) = onig_search(
    &reg, input, input.len(), 0, input.len(),
    Some(OnigRegion::new()), ONIG_OPTION_NONE,
);

assert!(result >= 0);
assert_eq!(result, 6); // match starts at byte 6

Module Structure

Each C source file maps 1:1 to a Rust module:

C File	Rust Module	Purpose
regparse.c	regparse	Pattern parser
regcomp.c	regcomp	AST-to-bytecode compiler
regexec.c	regexec	VM executor
regint.h	regint	Internal types and opcodes
oniguruma.h	oniguruma	Public types and constants
regenc.c	regenc	Encoding trait
regsyntax.c	regsyntax	12 syntax definitions
regset.c	regset	Multi-regex search (RegSet)
regerror.c	regerror	Error messages
regtrav.c	regtrav	Capture tree traversal

Modules

api

encodings

error

oniguruma

prelude

Prelude

regcomp

regenc

regerror

regexec

regint

regparse

regparse_types

regset

regsyntax

regtrav

scanner

unicode