CODEWITHSUNDEEP
vimneovim
kkirsche
kkirsche

Reputation: 1257

How to configure vim syntax highlighting for escape sequences like \n and \r within strings?

I've been working on a custom syntax highlighter for the Spike fuzzing API.

https://github.com/kkirsche/spike.vim

Very simple API, so it's a very simple file.

With this said, within strings, there are escape sequences such as \n for a new line, \r for a carriage return, as is common in many programming languages such as Python, C, etc. As these get interpreted differently, I want to highlight them in the same way you'd find for those programming languages.

My understanding is that these should be a match definition, but to be honest I'm not sure — and I don't know what type of character this is per Vim's different types (e.g. Comment, String, Special, Function, etc.)

What is the proper way to handle highlighting escape sequences such as these within a VIM syntax highlighting file?

Upvotes: 1

Views: 1311

Answers (1)

Ingo Karkat
Ingo Karkat

Reputation: 172768

Looking at some syntax scripts that ship with Vim, all seem to (mostly) agree to link this to the SpecialChar default highlighting group (which itself is linked to Special by default):

$VIMRUNTIME/syntax/c.vim:

syn match   cSpecial    display contained "\\\(x\x\+\|\o\{1,3}\|.\|$\)"
syn region  cString     start=+\(L\|u\|u8\|U\|R\|LR\|u8R\|uR\|UR\)\="+ skip=+\\\\\|\\"+ end=+"+ contains=cSpecial,cFormat,@Spell extend
hi def link cSpecial        SpecialChar

$VIMRUNTIME/syntax/java.vim:

syn match   javaSpecialChar  contained "\\\([4-9]\d\|[0-3]\d\d\|[\"\\'ntbrf]\|u\x\{4\}\)"
hi def link javaSpecialChar     SpecialChar

$VIMRUNTIME/syntax/javascript.vim:

syn match   javaScriptSpecial          "\\\d\d\d\|\\."
syn match   javaScriptSpecialCharacter "'\\.'"
hi def link javaScriptSpecial       Special
hi def link javaScriptSpecialCharacter  javaScriptSpecial

The :help group-name agrees with that:

  *Special        any special symbol
   SpecialChar    special character in a constant
   Tag            you can use CTRL-] on this
   Delimiter      character that needs attention
   SpecialComment special things inside a comment

Upvotes: 1

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