How can I throw a user-friendly error that does not point to the code that fails?

Questions
1

For my abbreviations functionality I’d like to halt compilation when an abbreviation is detected that is not available in the global dictionary. I do this with an assert:

#assert(abbr in GLOBALDICT.keys(), message: "

!!!!!!!!! ABBREVIATION MISSING !!!!!!!!!!

The abbreviation " + abbr + " does not exist in the abbreviation dictionary.

")

The problem is that the user sees redundant information when they forget to supply an abbreviation:

[typst]: Compiling scratch.typ to scratch.pdf...error: assertion failed: 

!!!!!!!!! ABBREVIATION MISSING !!!!!!!!!!

The abbreviation CTROUGHT does not exist in the abbreviation dictionary.


    ┌─ scratch/scratch.typ:352:0
    │  
352 │ ╭ assert(abbr in GLOBALDICT.keys(), message: "
353 │ │ 
354 │ │ !!!!!!!!! ABBREVIATION MISSING !!!!!!!!!!
355 │ │ 
356 │ │ The abbreviation " + abbr + " does not exist in the abbreviation dictionary.
357 │ │ 
358 │ │ ")
    │ ╰──^

For the user, it really does not matter in what function the assert is triggered, they should just see the notice. Is that possible in Typst?

2

I don’t think there is any useful facility in Typst for now that helps with that. Best I could manage with Typst is to use panic instead.

watching test.typ
writing to test.pdf

[15:45:23] compiled with errors

error: panicked with: "glossarium@0.5.6 error : glossary is empty. Use `register-glossary(entry-list)` immediately after `make-glossary`."
     ┌─ @preview/glossarium:0.5.6/themes/default.typ:1131:8
     │
1131 │         panic(__error_message(none, __glossary_is_empty))
     │         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
3

Thanks, I had also found panic but it has the same problem. I might open an issue as stopping a render without it looking like a bug would be a good feature I think.

4

Since this is a package, this seems relevant: Support for emitting custom warnings · Issue #1322 · typst/typst · GitHub, Logging function for debug output · Issue #1669 · typst/typst · GitHub. As an author of your own thing, I wouldn’t care about double output, this also happens in Python and probably somewhere else. So making this for non-package errors seems unnecessary. And package-related stuff is discussed in those issues.