Apple HFS+ NFD-like Unicode Normalization Library for Rust

HFS+, the file system formerly used in Apple macOS, uses a unique Unicode normalization similar to NFD.

• https://developer.apple.com/library/archive/technotes/tn/tn1150table.html
• https://developer.apple.com/library/archive/technotes/tn/tn1150.html

This library composes or decomposes Unicode code points according to the normalization. e.g.

• Université[U+00E9] de Paris (Common) ⇔ Université[U+0065 U+0301] de Paris (HFS+)
• アップ[U+30D7]ル (Common) ⇔ アップ[U+30D5 U+309A]ル (HFS+)

How to use

Add this library hfs_nfd to your Cargo.toml.

```toml [dependencies] anotherlibrary1 = "" anotherlibrary2 = ""

snip

hfs_nfd = "0.1.1" # <= Here

snip

```

Then, use these functions:

```rust use hfsnfd::{composefromhfsnfd,decomposeintohfs_nfd}

asserteq!(decomposeintohfsnfd("Universit\u{00E9}"), "Universite\u{0301}".tostring()); asserteq!(composefromhfsnfd("アッフ\u{309A}ル"), "アッ{30D7}ル".tostring()); ```

Restrictions

In HFS+, Korean Hangul characters are also composed or decomposed in the way other than what is listed on the table.

In addition, the Korean Hangul characters with codes in the range u+AC00 through u+D7A3 are illegal and must be replaced with the equivalent sequence of conjoining jamos, as described in the Unicode 2.0 book, section 3.10.

I've not implemented it yet.

Please don't hasitate to send a PR on this if you feel inconvenience. These pages may be help you:

• https://www.unicode.org/versions/Unicode13.0.0/ch03.pdf
• https://www.unicode.org/versions/Unicode2.0.0/ch03.pdf
• https://en.wikipedia.org/wiki/HangulJamo(Unicode_block)