Override counter

[shivangp76]

Hi,

Thank you for making this package! I was wondering if it is possible to override a counter for a specific instance of a mathblock. For example, I made an "Exercise" block using code similar to that provided in the README. I want to have a default counter, but be able to override the counter with specific text. Something like:

#exercise[
#lorem(100)
]
#exercise["6.7(a)"][
#lorem(100)
]
#exercise[
#lorem(100)
]

to render something like:

Exercise 1
Exercise 6.7(a)
Exercise 2

[jbirnick]

Hey, thanks for your question!

It seems like you don't even want the exercise environment itself to be counted. In that case, the best solution right now is to make a second exercise-extra environment, which looks just like the first one, but has no counter:

#import "@preview/great-theorems:0.1.1": *
#import "@preview/rich-counters:0.2.1": *

#show: great-theorems-init

#let mathcounter = rich-counter(
  identifier: "mathblocks",
  inherited_levels: 0
)

#let exercise = mathblock(
  blocktitle: "Exercise",
  counter: mathcounter,
)

#let exercise-extra = mathblock(
  blocktitle: "Exercise",
  // put same properties as `exercise` except the counter
)

#exercise[
  Some exercise.
]

#exercise-extra[
  Uncounted exercise.
]

#exercise[
  Some exercise.
]

Now you can adjust the prefix for that environment on an individual basis:

#exercise[
  Some exercise.
]

#exercise-extra(prefix: [*Exercise 6.7(a).*])[
  Uncounted exercise.
]

#exercise[
  Some exercise.
]

Also note that titles exist, if you want to utilize them:

#exercise[
  Some exercise.
]

#exercise(title: [6.7(a) in the book])[
  Some other exercise.
]

#exercise[
  Some exercise.
]

[jbirnick]

Replacing the counter value directly is currently not possible. If more people want this feature, I can add it though.

So if you would like to have this feature (to replace the counter value with your own number) please comment here.

[shivangp76]

Thank you for the suggestions! The extra suffix seems a bit clunky. It also requires that I specify the full blocktitle, so I have to retype "Exercise". This means I can't edit the markup on "Exercise" globally. For this reason, I am in favor of replacing the counter value directly.

For reference, here is the Latex I am aiming to replicate:

  \newcounter{exercisenum}
  \newenvironment{exercise}[1][\theexercisenum]{
    \IfValueT{#1}{
      \stepcounter{exercisenum}
    }
    \textbf{Exercise #1:}
  }
  {}

[jbirnick]

I have implemented this now. Please have a look at the README, you have to pass number: ... to the environment.

Note that this is not yet on Typst Universe (and will take a few days at least). Please download lib.typ from this repo and use #import "lib.typ": * instead of importing the package.

Could you try it and tell me if it works for you or if anything breaks?

[shivangp76]

Thank you for working on this! It works well. The trick mentioned here doesn't work, but I suspect that will change as #3 get resolved anyway.

[jbirnick]

Wait, what do you mean by this trick doesn't work? It should work exactly the same as before, the code which handles this hasn't been changed. Can you give a reproducible example of what doesn't work?

[shivangp76]

I think I did a poor job of testing it last time. It looks fine.

[jbirnick]

Okay thanks. I will close this issue then. I hope to release the functionality to Typst Universe soon.