evil-digraph: How to add a digraph for '🙂' character

[ju-sh]

Issue type

• Question: How to add digraph for '🙂' character? I was trying to have ':)'

I think this is a 4-byte unicode character.
Is it possible to have digraphs for 4-byte unicode?

Environment

Emacs version: 27.1
Operating System: Debian 11
Evil version: 1.15.0
Evil installation type: MELPA
Graphical/Terminal: X
Tested in a make emacs session (see CONTRIBUTING.md): No

Reproduction steps

Add this to init file:

((?: ?\)) . ?\xd83dde42)

Expected behavior

Digraph should be loaded

Actual behavior

Error message: error: Hex character out of range: \xd83dde42...

Further notes

Not sure if I got the unicode hex for '🙂' wrong..

[tomdl89]

On my machine, that emoji looks to have a hex value of #x1f642 so this should work:

(push '((?: ?\)) . ?\x1f642) evil-digraphs-table-user)

but then so should just using the emoji literally in your init file:

(push '((?: ?\)) . ?🙂) evil-digraphs-table-user)

[tomdl89]

ChatGPT explanation if you are interested:

In short, they were looking at the UTF-16 “surrogate pair” rather than the single Unicode code point.

Single Code Point

• The “slightly smiling face” emoji is U+1F642 in Unicode.

UTF-16 Surrogate Pair

• In UTF-16 encoding, characters outside the Basic Multilingual Plane (BMP) need two 16-bit code units.
• For 🙂, the surrogate pair is 0xD83D 0xDE42.

So, when someone says “it’s U+d83dde42,” they are simply combining the two surrogate halves into one notation (D83D and DE42). It’s still the same emoji, but shown in UTF-16 rather than the single Unicode point in hex.