penmanship

A Rust library for Unicode character lookup via text patterns. Convert text aliases like "...", "alpha", "(c)" to their corresponding Unicode characters (…, α, ©).

Features

no_std compatible: Works in embedded and bare-metal environments
Zero runtime overhead: Uses compile-time perfect hash maps via phf
No allocations: Returns static string references
Feature-gated: Enable only the character categories you need
Comprehensive: Supports punctuation, math, Greek letters, fractions, currency, symbols, HTML entities, emoji, and more
Safe: Forbids unsafe code and maintains strict quality standards

Quick Start

Add penmanship to your Cargo.toml:

[dependencies]
penmanship = "0.1"

Basic usage:

use penmanship::lookup;

fn main() {
    // Look up Unicode characters by pattern
    if let Some((character, description)) = lookup("...") {
        println!("{} - {}", character, description);
        // Output: … - horizontal ellipsis
    }

    if let Some((character, _)) = lookup("alpha") {
        println!("{}", character);  // Output: α
    }

    if let Some((character, _)) = lookup("(c)") {
        println!("{}", character);  // Output: ©
    }

    // Unknown patterns return None
    assert_eq!(lookup("unknown"), None);
}

Supported Categories

All categories are enabled by default via the full feature. Examples:

// Punctuation
lookup("...")       // … - horizontal ellipsis
lookup("em")        // — - em dash
lookup("'l")        // ' - left single quotation mark

// Math
lookup("!=")        // ≠ - not equal to
lookup("->")        // → - rightwards arrow
lookup("infinity")  // ∞ - infinity

// Greek letters (case-sensitive)
lookup("alpha")     // α - greek small letter alpha
lookup("Alpha")     // Α - greek capital letter alpha

// Fractions
lookup("1/2")       // ½ - fraction one half

// Currency
lookup("euro")      // € - euro sign

// Symbols
lookup("(c)")       // © - copyright sign
lookup("deg")       // ° - degree sign

// Superscripts & Subscripts
lookup("^2")        // ² - superscript two
lookup("_2")        // ₂ - subscript two

// HTML entities (2200+ supported)
lookup("&nbsp;")    // (non-breaking space)
lookup("&lt;")      // < - less than

// Emoji (1800+ shortcodes)
lookup(":smile:")   // 😄 - grinning face with smiling eyes
lookup(":heart:")   // ❤️ - red heart

For a complete list of all supported patterns, see docs/mappings.md.

Feature Flags

By default, all categories are enabled via the full feature. To use only specific categories:

[dependencies]
penmanship = { version = "0.1", default-features = false, features = ["punctuation", "math", "greek"] }

Available features:

full (default) - All categories
punctuation - Punctuation and typography
math - Mathematical operators and symbols
greek - Greek letters
fractions - Fraction characters
currency - Currency symbols
symbols - Miscellaneous symbols
superscripts - Superscript characters
subscripts - Subscript characters
html - HTML named character references
emoji - Emoji shortcode lookup (requires emojis crate)

Design Philosophy

no_std compatible: No standard library required, works in embedded environments
Compile-time: All mappings use perfect hash functions computed at compile time
Zero allocations: All strings are static references
Library-only: Pure library with no binary, focused on being a building block
Feature-gated: Pay only for what you use

Development Notes

This project uses a whitelist approach to .gitignore
100% test coverage maintained
Strict linting: no unsafe code, all items documented

Contributing

Contributions are welcome! See CONTRIBUTING.md for guidelines.

Security

For security vulnerabilities and reporting guidelines, see SECURITY.md.

Acknowledgments

Emoji support provided by the emojis crate
HTML entities based on the WHATWG HTML Living Standard

License

Licensed under the Apache License, Version 2.0. See LICENSE.txt for details.

penmanship 0.1.0