How can I quickly patch code blocks syntax higlighting

Questions
1

I’ll take my problem as an example, but I welcome more generic solutions for fixing syntax highlighting grammar because this is not an isolated problem.

With this typst document:

```f95
INTEGER :: i, j
CHARACTER :: c
CHARACTER(5) :: string
LOGICAL :: yes
```

which renders as:

image
image388×166 10.7 KB

how can I patch the raw or define a custom command that would use exactly what the syntax highlighter already does, but add an exceptional rule to add CHARACTER to a list of detected keywords? Quick-and-dirty is acceptable.

2

For a quick and dirty solution, you can manually color specific keywords by setting the text fill, e.g. in your example:

#show raw.where(lang: "f95", block: true): it => {
  show "CHARACTER": set text(fill: rgb("D73948"))
  it
}

Since this seems(?) like a compiler bug, this may be the only way to do it before it gets patched. There are some packages like pleast which claim to give you better control, but I haven’t looked into it.

3

Perfect, I’m new too typst so I am not yet able to patch command on my own, but from your example this seems quite easy. Thanks.

4

Yes, this should be quite easy (just specify the keyword and desired color), you can even use regex. Though if you find yourself writing regular expressions for matching keywords it’s probably time to look into more “proper” solutions :sweat_smile:

5

For potentially interested users I ended up using regex anyway, now it does the job nicely. I put this in an independent file that might receive other ad hoc fixes.

// Fortran syntax highlighting CHARACTER (case insensitive) fix.
#let f95_character_fix(body) = {
  show raw.where(lang: "f95"): it => {
    show regex("(?i)character"): set text(fill: rgb("#d73948"))
    it
  }
  body
}

and then import and

#show: f95_character_fix

in your main doc applies the fix.