unicode_names2

Time and memory efficiently mapping characters to and from their Unicode 16.0 names, at runtime and compile-time.

fn main() {
    println!("☃ is called {}", unicode_names2::name('☃')); // SNOWMAN
    println!("{} is happy", unicode_names2::character("white smiling face")); // ☺
    // (NB. case insensitivity)
}

The maps are compressed using similar tricks to Python's unicodedata module, although those here are about 70KB (12%) smaller.

Documentation

lib.rs:

Convert between characters and their standard names.

This crate provides two functions for mapping from a char to the name given by the Unicode standard (16.0). There are no runtime requirements so this is usable with only core (this requires specifying the no_std cargo feature). The tables are heavily compressed, but still large (500KB), and still offer efficient O(1) look-ups in both directions (more precisely, O(length of name)).

    println!("☃ is called {:?}", unicode_names2::name('☃')); // SNOWMAN
    println!("{:?} is happy", unicode_names2::character("white smiling face")); // ☺
    // (NB. case insensitivity)

Source.

Macros

The associated unicode_names2_macros crate provides two macros for converting at compile-time, giving named literals similar to Python's "\N{...}".

• named_char!(name) takes a single string name and creates a char literal.
• named!(string) takes a string and replaces any \\N{name} sequences with the character with that name. NB. String escape sequences cannot be customised, so the extra backslash (or a raw string) is required, unless you use a raw string.

#![feature(proc_macro_hygiene)]

#[macro_use]
extern crate unicode_names2_macros;

fn main() {
    let x: char = named_char!("snowman");
    assert_eq!(x, '☃');

    let y: &str = named!("foo bar \\N{BLACK STAR} baz qux");
    assert_eq!(y, "foo bar ★ baz qux");

    let y: &str = named!(r"foo bar \N{BLACK STAR} baz qux");
    assert_eq!(y, "foo bar ★ baz qux");
}

Cargo-enabled

This package is on crates.io, so add either (or both!) of the following to your Cargo.toml.

[dependencies]
unicode_names2 = "0.2.1"
unicode_names2_macros = "0.2"