Markdown: unnecessary space is inserted between Korean & English words

[appetizermonster]

Prettier 1.14.2
Playground link

--parser markdown

Input:

안녕하세요. 저는 Prettier을 굉장히 잘 사용하고 있습니다.
그런데 Prettier는 영어와 한글 사이에 무조건 빈 공간을 입력하고 있어요.
... ㅠㅠ

Output:

안녕하세요. 저는 Prettier 을 굉장히 잘 사용하고 있습니다.
그런데 Prettier 는 영어와 한글 사이에 무조건 빈 공간을 입력하고 있어요.
... ㅠㅠ

Expected behavior:

안녕하세요. 저는 Prettier을 굉장히 잘 사용하고 있습니다.
그런데 Prettier는 영어와 한글 사이에 무조건 빈 공간을 입력하고 있어요.
... ㅠㅠ

Currently, markdown formatting automatically inserts unnecessary spaces between Korean & English characters.
I guess that the issue is caused by #3026 (cjk support in markdown).

Korean already has the syntax for spacing, So automatically inserting spaces between e(english) & k(korean) is not neccesary.

[ikatyang]

Is the space there invalid (i.e., its meaning changed) or unnecessary? We added spaces there for readability, I know it's valid in Chinese and Japanese, but I'm not sure if it's valid in Korean.

[appetizermonster]

no critical meaning changes but it's awkward mostly. so I think there is no need to insert spaces for Korean.

[ikatyang]

According to Korean Text Layout and pp. 518 of CJKV Information Processing (ref: ikatyang/cjk-regex#48), the convention is to use extra space:

Space setting between character classes: Set up spaces between each character class.

If the document is primarily composed of CJKV glyphs with some glyphs sprinkled throughout, then the convention or principle is to use extra space to these two classes of glyphs.

[appetizermonster]

Thank you for letting me know about the official(or standard) documents.
but I couldn't understand what the documents say 😢
Anyway in reality, we don't insert space between Latin & Hangul, we just follow the Hangul spacing rules.

Here are some examples:

• Google (in Korean) https://support.google.com/accounts/answer/463?hl=ko
  

• Microsoft (in Korea) https://support.microsoft.com/ko-kr/help/10558/microsoft-account-refunds-for-purchases-and-subscriptions
  

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and this is the case where we follow the Hangul spacing rules in Latin characters:
https://support.google.com/accounts/answer/463?hl=ko