https://github.com/aim2bpg/hoozmo
Hoozmo is a hobby regex engine written in Ruby, created while learning from Hoozuki.
https://github.com/aim2bpg/hoozmo
github-pages regex-engine ruby wasm webassembly
Last synced: 4 months ago
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Hoozmo is a hobby regex engine written in Ruby, created while learning from Hoozuki.
- Host: GitHub
- URL: https://github.com/aim2bpg/hoozmo
- Owner: aim2bpg
- License: mit
- Created: 2025-12-22T13:39:49.000Z (6 months ago)
- Default Branch: main
- Last Pushed: 2026-02-07T16:01:51.000Z (5 months ago)
- Last Synced: 2026-02-08T00:15:24.740Z (5 months ago)
- Topics: github-pages, regex-engine, ruby, wasm, webassembly
- Language: Ruby
- Homepage: https://aim2bpg.github.io/hoozmo/
- Size: 56.6 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Hoozmo (Hoozuki-mod)
[](https://github.com/aim2bpg/hoozmo/actions/workflows/ci.yml) [](https://github.com/aim2bpg/hoozmo/actions/workflows/pages/pages-build-deployment)
Hoozmo is a hobby regex engine written in Ruby, created while learning from [Hoozuki](https://github.com/ydah/hoozuki).
## Quick start
Install dependencies:
```bash
npm install
bundle install
```
Run tests:
```bash
bundle exec rspec
```
Build production assets:
```bash
npm run build
# output -> dist/
```
Run the frontend dev server:
```bash
npm run dev
# open http://localhost:3000
```
## Supported features
Hoozmo provides a minimal, educational regular-expression engine suitable for learning and experimentation. The parser and matcher in `lib/` (and the browser demo) support the core constructs below.
- **Literals**: match single characters exactly (examples: `a`, `b`, `1`).
- **Concatenation**: adjacent tokens are matched in sequence (example: `abc` matches `abc`).
- **Grouping**: parentheses `()` create groups for sequencing or alternation (example: `a(bc)d`).
- **Alternation / Choice**: the `|` operator selects between alternatives (examples: `a|b`, `a|b|c`).
- **Nested groups**: groups may be nested to express more complex structure (example: `a((b|c)|d)e`).
- **Kleene closure / Repetition**: `*` matches the preceding element zero or more times (example: `a*`).
- **One or more**: `+` matches the preceding element one or more times (example: `a+`).
- **Optional**: `?` makes the preceding element optional (zero or one) (example: `a?`).
- **Escape sequences**: special characters can be escaped with backslash `\` (examples: `\*`, `\(`, `\)`, `\|`, `\\`).
- **Substring matching**: patterns match anywhere in the input string (like most regex engines).
Notes:
- This project focuses on clarity and pedagogical value rather than full PCRE compatibility.
- To add features, update the parser in `lib/hoozmo/parser.rb` and add tests under `spec/`.
Examples (these are also available in the browser demo):
- `abc` — literal concatenation, matches exactly `abc`.
- `a|b` — alternation, matches `a` or `b`.
- `a|b|c` — multiple alternatives.
- `a(b|c)d` — grouping with alternation (e.g. matches `acd`).
- `a((b|c)|d)e` — nested grouping with alternation (e.g. matches `ade`).
- `a*` — Matches zero or more (e.g. `a*`).
- `a+` — Matches one or more (e.g. `a+`).
- `a?` — Optional (zero or one, e.g. `a?`).
- `a+b*c?` — Combined quantifiers example.
- `a\*b` — Escaped asterisk (matches literal `a*b`).
- `cat` — Substring matching (finds `cat` anywhere in the input).
### Browser demo examples (pattern + test string)
- Pattern: `abc` — Test string: `abc`
- Pattern: `a|b` — Test string: `b`
- Pattern: `a|b|c` — Test string: `c`
- Pattern: `a(b|c)d` — Test string: `acd`
- Pattern: `a((b|c)|d)e` — Test string: `ade`
- Pattern: `a*` — Test string: `aaa`
- Pattern: `a+` — Test string: `aaa`
- Pattern: `a?` — Test string: `a`
- Pattern: `a+b*c?` — Test string: `aabbc`
- Pattern: `a\*b` — Test string: `a*b` (escaped asterisk)
- Pattern: `cat` — Test string: `concatenate` (substring match)
Browser demo: open the project in a browser (or run the dev server with `npm run dev`) and open `index.html` — the Examples panel on the page inserts the pattern and test string into the fields when clicked.
If you want to extend the parser with additional features, add tests under `spec/` and update `lib/hoozmo/parser.rb` and `lib/hoozmo.rb` accordingly.