https://github.com/pablohirafuji/elm-char-codepoint

Code point operations in Elm
https://github.com/pablohirafuji/elm-char-codepoint

char codepoints elm

Last synced: 9 days ago
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Code point operations in Elm

• Host: GitHub
• URL: https://github.com/pablohirafuji/elm-char-codepoint
• Owner: pablohirafuji
• License: mit
• Created: 2017-03-10T19:43:00.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2017-03-17T19:28:22.000Z (almost 8 years ago)
• Last Synced: 2024-11-08T06:19:46.132Z (2 months ago)
• Topics: char, codepoints, elm
• Language: Elm
• Homepage: http://package.elm-lang.org/packages/pablohirafuji/elm-char-codepoint/latest
• Size: 116 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: Readme.md
  • License: LICENSE

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README

        
# Code Point

Convert char to code point and code point to string, similar to javascript's `String.codePointAt` and `String.fromCodePoint`. [Demo](https://pablohirafuji.github.io/elm-char-codepoint/).

## What's the difference between `Char.toCode` and `Char.CodePoint.fromChar`?

From [MDN](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/String/charCodeAt):

> The `charCodeAt()` method returns an integer between 0 and 65535 representing the UTF-16 code unit at the given index (the UTF-16 code unit matches the Unicode code point for code points representable in a single UTF-16 code unit, but might also be the first code unit of a surrogate pair for code points not representable in a single UTF-16 code unit, e.g. Unicode code points > 0x10000). If you want the entire code point value, use `codePointAt()`.

This mean that not all chars exists in a single 16 bits representation, and `Char.toCode` only returns the first 16 bits code of any given char.

Here is an example to demonstrate how this can affect the output of `Char.toCode` and how `Char.CodePoint.fromChar` fix that:

```elm

Char.toCode '𝔸' == 55349

Char.fromCode 55349 == '�'

Char.CodePoint.fromChar '𝔸' == 120120

Char.CodePoint.toString 120120 == "𝔸"

```

You can try different chars in this [demo](https://pablohirafuji.github.io/elm-char-codepoint/).