Morsecode

This is morsecode translator for English, Korean, Numbers.

It seems quite easy to translate English and Numbers but Korean. Korean letter is composed with initial sound(cho-sung, 초성), middle sound(joong-sung, 중성), last sound(jong-sung, 종성). So when it is being encoding, it should be seperated each sound and when it is being decoding, it should be combining back for complete letter.

Here is a reference:

1. each sound:

   • initial sound
     • "ㄱ", "ㄲ", "ㄴ", "ㄷ", "ㄸ", "ㄹ", "ㅁ", "ㅂ", "ㅃ", "ㅅ", "ㅆ", "ㅇ", "ㅈ", "ㅉ", "ㅊ", "ㅋ", "ㅌ", "ㅍ", "ㅎ"
   • middle sound
     • "ㅏ", "ㅐ", "ㅑ", "ㅒ", "ㅓ", "ㅔ", "ㅕ", "ㅖ", "ㅗ", "ㅘ", "ㅙ", "ㅚ", "ㅛ", "ㅜ", "ㅝ", "ㅞ", "ㅟ", "ㅠ", "ㅡ", "ㅢ", "ㅣ"
   • last sound(it can be empty)
     • "", "ㄱ", "ㄲ", "ㄳ", "ㄴ", "ㄵ", "ㄶ", "ㄷ", "ㄹ", "ㄺ", "ㄻ", "ㄼ", "ㄽ", "ㄾ", "ㄿ", "ㅀ", "ㅁ", "ㅂ", "ㅄ", "ㅅ", "ㅆ", "ㅇ", "ㅈ", "ㅊ", "ㅋ", "ㅌ", "ㅍ", "ㅎ"

2. letters:

   • initial sound + middle sound
     • "가", "까", ..., "개", "깨", ..., "희", "히"
   • initial sound + middle sound + last sound
     • "각", "깍", ..., "객", "깩", ..., "힢", "힣"
   • combination table

     ㄱ
     가	각	갂	간	...					갛
     개	객	갞	갠						갷
     ...
     긔	긕	긖	긘						긯
     기	긱	긲	긴						깋
     x 19 (fo all initial sound)

Encoding process

1. Getting unicode

   • charCodeAt(0) returns Unicode of a letter

2. Calculating index of each sound from unicode

   • Refer to the reference above, the number of possible Korean letter is 19(initial) * 21(middle) * 28(last) and all possible letters are sequantially placed from the initial Korean letter "가" which is composed by "ㄱ"(initial) + "ㅏ"(middle) + ""(last).
     • Last sound: The last sound must be a remainder by 28 because the number of last sound is 28.
     • Middle sound: To get next sound, minus the result of last sound from unicode of the letter. And then divide by 28 to consider about middle sound. After that getting remainder by 21.
     • Initial sound: Same with middle sound until dividing by 28. Minus middle sound to calculate left initial sound. And then divide by 21.

3. Returning matching morsecode from morsecode map

   • Find the letter using the indexes from each sound array

Decoding process:

1. Getting each sound
   • Find each sound from morse code map and stick together to tell that it will be a letter
2. Translating to a letter
   • Find indexes from each character of sounds
   • Calculate unicode using each index.
     • '가'.charCodeAt(0) + index of initial sound * 21 * 28 + index of middle sound * 28 + index of last sound
   • Translating to character from unicode
     • String.fromCharCord()

Note:

1. Each Korean letter should have two spaces
   • If each letter has one space between, it's impossible to recognize combined consonants.

Usage:

var morsecode = new morsecode();

// encode
// morsecode.encode(normal_string);
morsecode.encode('안녕 세상');
// -.- . ..-.  ..-. ... -.-     --. -.--  --. . -.-


// decode
// morsecode.decode(morsecode_string, type);
// type: 'kor' || 'eng'
morsecode.decode('-.- . ..-.  ..-. ... -.-     --. -.--  --. . -.-', 'kor');
// 안녕 세상