Editing Korean language and computers (section)

=== Hangul Syllables block ===
Pre-composed Hangul syllables in the Unicode [[Hangul Syllables]] block are algorithmically defined with the following formula:
: [(initial) × 588 + (medial) × 28 + (final)] + 44032

* Initial consonants
{{columns-list|colwidth=8em|{{ordered list|start=0
| [[wikt:ㄱ|ㄱ]]
| [[wikt:ㄲ|ㄲ]]
| [[wikt:ㄴ|ㄴ]]
| [[wikt:ㄷ|ㄷ]]
| [[wikt:ㄸ|ㄸ]]
| [[wikt:ㄹ|ㄹ]]
| [[wikt:ㅁ|ㅁ]]
| [[wikt:ㅂ|ㅂ]]
| [[wikt:ㅃ|ㅃ]]
| [[wikt:ㅅ|ㅅ]]
| [[wikt:ㅆ|ㅆ]]
| [[wikt:ㅇ|ㅇ]]
| [[wikt:ㅈ|ㅈ]]
| [[wikt:ㅉ|ㅉ]]
| [[wikt:ㅊ|ㅊ]]
| [[wikt:ㅋ|ㅋ]]
| [[wikt:ㅌ|ㅌ]]
| [[wikt:ㅍ|ㅍ]]
| [[wikt:ㅎ|ㅎ]]
}}}}

* Medial vowels
{{columns-list|colwidth=8em|{{ordered list|start=0
| [[wikt:ㅏ|ㅏ]]
| [[wikt:ㅐ|ㅐ]]
| [[wikt:ㅑ|ㅑ]]
| [[wikt:ㅒ|ㅒ]]
| [[wikt:ㅓ|ㅓ]]
| [[wikt:ㅔ|ㅔ]]
| [[wikt:ㅕ|ㅕ]]
| [[wikt:ㅖ|ㅖ]]
| [[wikt:ㅗ|ㅗ]]
| [[wikt:ㅘ|ㅘ]]
| [[wikt:ㅙ|ㅙ]]
| [[wikt:ㅚ|ㅚ]]
| [[wikt:ㅛ|ㅛ]]
| [[wikt:ㅜ|ㅜ]]
| [[wikt:ㅝ|ㅝ]]
| [[wikt:ㅞ|ㅞ]]
| [[wikt:ㅟ|ㅟ]]
| [[wikt:ㅠ|ㅠ]]
| [[wikt:ㅡ|ㅡ]]
| [[wikt:ㅢ|ㅢ]]
| [[wikt:ㅣ|ㅣ]]
}}}}

* Final consonants
{{columns-list|colwidth=8em|{{ordered list|start=0
| ''none''
| [[wikt:ㄱ|ㄱ]]
| [[wikt:ㄲ|ㄲ]]
| [[wikt:ㄳ|ㄳ]]
| [[wikt:ㄴ|ㄴ]]
| [[wikt:ㄵ|ㄵ]]
| [[wikt:ㄶ|ㄶ]]
| [[wikt:ㄷ|ㄷ]]
| [[wikt:ㄹ|ㄹ]]
| [[wikt:ㄺ|ㄺ]]
| [[wikt:ㄻ|ㄻ]]
| [[wikt:ㄼ|ㄼ]]
| [[wikt:ㄽ|ㄽ]]
| [[wikt:ㄾ|ㄾ]]
| [[wikt:ㄿ|ㄿ]]
| [[wikt:ㅀ|ㅀ]]
| [[wikt:ㅁ|ㅁ]]
| [[wikt:ㅂ|ㅂ]]
| [[wikt:ㅄ|ㅄ]]
| [[wikt:ㅅ|ㅅ]]
| [[wikt:ㅆ|ㅆ]]
| [[wikt:ㅇ|ㅇ]]
| [[wikt:ㅈ|ㅈ]]
| [[wikt:ㅊ|ㅊ]]
| [[wikt:ㅋ|ㅋ]]
| [[wikt:ㅌ|ㅌ]]
| [[wikt:ㅍ|ㅍ]]
| [[wikt:ㅎ|ㅎ]]
}}}}

To find the code point of "한" in Unicode:

* The value of the initial consonant (ㅎ) is 18.
* The value of the medial vowel (ㅏ) is 0.
* The value of the final consonant (ㄴ) is 4.

Substituting these values in the formula above yields [(18 × 588) + (0 × 28) + 4] + 44032 = 54620. The Unicode value of 한 is 54620 in decimal, <code>&amp;#54620;</code> in [[numeric character reference]], and U+D55C in hexadecimal Unicode notation.

==== How to code this in Rust ====

{{Irrelevant}}

With the below module, calling e.g. <syntaxhighlight lang="rs" inline>hangul::from_jamo('ㅎ', 'ㅏ', Some('ㄴ'))</syntaxhighlight> will return <syntaxhighlight lang="rs" inline>Some('한')</syntaxhighlight>.

<syntaxhighlight lang="rs">
mod hangul {
    const INITIAL_JAMO: [char; 19] = [
        'ㄱ', 'ㄲ', 'ㄴ', 'ㄷ', 
        'ㄸ', 'ㄹ', 'ㅁ', 'ㅂ', 
        'ㅃ', 'ㅅ', 'ㅆ', 'ㅇ', 
        'ㅈ', 'ㅉ', 'ㅊ', 'ㅋ', 
        'ㅌ', 'ㅍ', 'ㅎ', 
    ];
   
    const VOWEL_JAMO: [char; 21] = [
        'ㅏ', 'ㅐ', 'ㅑ', 'ㅒ',
        'ㅓ', 'ㅔ', 'ㅕ', 'ㅖ', 
        'ㅗ', 'ㅘ', 'ㅙ', 'ㅚ', 
        'ㅛ', 'ㅜ', 'ㅝ', 'ㅞ', 
        'ㅟ', 'ㅠ', 'ㅡ', 'ㅢ', 
        'ㅣ', 
    ];
   
    const FINAL_JAMO: [Option<char>; 28] = [
        None,       Some('ㄱ'), Some('ㄲ'), Some('ㄳ'),
        Some('ㄴ'), Some('ㄵ'), Some('ㄶ'), Some('ㄷ'),
        Some('ㄹ'), Some('ㄺ'), Some('ㄻ'), Some('ㄼ'), 
        Some('ㄽ'), Some('ㄾ'), Some('ㄿ'), Some('ㅀ'), 
        Some('ㅁ'), Some('ㅂ'), Some('ㅄ'), Some('ㅅ'), 
        Some('ㅆ'), Some('ㅇ'), Some('ㅈ'), Some('ㅊ'), 
        Some('ㅋ'), Some('ㅌ'), Some('ㅍ'), Some('ㅎ'), 
    ];
   
    const GA_LOCATION: u32 = '가' as u32; // = 44_032
   
    pub fn from_jamo(initial: char, medial: char, last: Option<char>) -> Option<char> {
        if !(
            self::INITIAL_JAMO.contains(&initial)
            && self::VOWEL_JAMO.contains(&medial)
            && self::FINAL_JAMO.contains(&last)
        ) {
            return None;
        }
        char::from_u32(
            self::GA_LOCATION
            + 588 * (INITIAL_JAMO.iter().position(|&c| c == initial)? as u32)
            + 28 * (VOWEL_JAMO.iter().position(|&c| c == medial)? as u32)
            + FINAL_JAMO.iter().position(|&c| c == last)? as u32
        )
    }
}
</syntaxhighlight>