Unicode character classification

  • characters of length 1
  • characters of length 2
  • characters of length 0

The length mentioned here refers to the printed length of the characters, that is, the length seen by the eyes

Characters of length 1

Most unicode characters are characters with a length of 1, such as the commonly used tab character, ascii characters.

a b c d , . ┼ ┬ │

Characters of length 2

Characters with a typographical width of 2 refer primarily to East Asian pictographs and related special punctuation, as well as full-width characters.

你好啊！《》
안녕하세요
こんにちは

They need to occupy two grids in the UI interface. Then aligning them requires special fonts that align 2:1 with width 1 characters.Here is a commonly used font.

https://github.com/be5invis/Sarasa-Gothic/

These characters have a special property called East Asian Width. They are included in the unicode standard, so they can be used as a programming basis.

Links to the unicode standard: https://www.unicode.org/reports/tr11/tr11-40.html

In perl's unicode documentation, corresponding properties are also provided to use.

This represents a wide character, occupying two spaces:

\p{EA=W}

This represents a full-width character, which also occupies two spaces:

\p{EA=F}

The above information can be found here:

https://perldoc.perl.org/perlunicook

https://perldoc.perl.org/perlunicode

Characters of length 0

In some languages, there are special characters whose string length is 1, but they do not occupy physical space on the interface, they will be attached to the previous characters.they are called nonspacing characters.Occurs in Thai and Arabic, as well as Hebrew

◌ั ◌ึ ◌ุ

Please look at the above characters, they cannot appear alone, they must be used in combination with the previous entity characters, and then they will appear above or below the previous characters.

These characters are called Nonspacing characters in the unicode standard, and then they have the following properties that can be used for programming

\p{gc:Mn}

To support Thai, or Arabic, or Hebrew, like East Asian languages, we also need a special font that can be aligned.In general, the system's default monospaced font can align them