Dollar signs in comments incorrectly trigger TeX rendering

[kennyjwilli]

Hi! Clerk has been excellent overall, but I've encountered an issue with dollar signs in comments being interpreted as TeX delimiters.

Problem:

When writing comments that include dollar amounts, Clerk treats them as TeX expressions. For example:

;; showing the dual-fuel advantage grows from ~$50K at low volatility to ~$115K at high volatility.

This renders using the TeX renderer instead of displaying as plain text.

Current Workaround:

I need to escape each dollar sign:

;; showing the dual-fuel advantage grows from ~\$50K at low volatility to ~\$115K at high volatility.

This becomes tedious quickly since we write dollar amounts frequently and never use TeX in our codebase.

Question:

Is there a way to disable TeX rendering in comments, or a configuration option to prevent dollar signs from triggering the TeX parser? Any suggestions for a better solution would be appreciated.

[borkdude]

I think it might be possible to disable the TeX viewers by overriding :nextjournal.markdown/formula and :nextjournal.markdown/block-formula in the default viewers by just letting them pass through the string as is.
This is probably a combination of reset-viewers! + update-viewers + default-viewers.

[kennyjwilli]

Excellent idea @borkdude, thank you! For others, here's what I've done:

(clerk/reset-viewers! (clerk/update-viewers clerk/default-viewers
                        {#(= 'nextjournal.clerk.viewer/markdown-viewer (:name %))
                         (fn [viewer]
                           (update viewer :add-viewers
                             (fn [viewers]
                               (map (fn [{:keys [name] :as viewer}]
                                      (cond-> viewer
                                        (#{:nextjournal.markdown/formula
                                           :nextjournal.markdown/block-formula} name)
                                        (assoc :render-fn '(fn [v] (str "$" v "$"))))) viewers))))}))

[borkdude]

Btw, it's not incorrect that dollars signs trigger TeX rendering, this is by design in clerk, but good that you've found a way to disable it. I think this could be closed now, @mk ?

[kennyjwilli]

Unfortunately, this isn't a complete solution. When a dollar sign appears inside other formatted markdown (like bold text), the markdown renders literally instead of being formatted.

For example, this markdown comment:

;; **Threshold 1: (~$125K)** - $240K/quarter

Renders as:

I tried wrapping the value in dollar signs to escape it:

(assoc
  :transform-fn clerk/mark-presented
  :render-fn '(fn [v] (nextjournal.clerk/md (str "$" v "$"))))

However, this causes an infinite loop (I think - the back just spins and then Chrome asks me to kill it) that prevents the notebook from loading in the browser.

Do you have any suggestions for restoring full markdown functionality while keeping TeX disabled?

[zampino]

I guess a (cleaner?) option to turn off LaTeX, would be to dynamically build/change the java parser given a set of options passed around here
https://github.com/nextjournal/markdown/blob/6f90b5129eff8cf711d94a0c5bb6288bd0b99e3e/src/nextjournal/markdown/impl.clj#L297

[borkdude]

Well, that's not a public API. Is there no way currently in nextjournal.markdown to disable TeX parsing as a public option?

[borkdude]

Haven't tried this yet but would it be possible to intercept the text before it's processed as markdown? Then you could manually escape $ with \$

[mk]

Well, that's not a public API. Is there no way currently in nextjournal.markdown to disable TeX parsing as a public option?

I think introducing a public option (for nextjournal.markdown, not tied to a parser implementation) to turn off LaTeX parsing is the way to go.

[borkdude]

Agreed @mk. Any ideas how to use this from clerk notebooks? Should it then become also a clerk option somehow?
I can work on this next week when I'm back from the Conj, if anyone else isn't getting to this yet.

[borkdude]

In nextjournal.markdown (parse "**Threshold 1: (~$125K)** - $240K/quarter") returns:

{...
:content
 [{:type :paragraph,
   :content
   [{:type :text, :text "**Threshold 1: (~"}
    {:type :formula, :text "125K)** - "}
    {:type :text, :text "240K/quarter"}]}],

which imo is incorrect. it should be something like:

[{:type :paragraph,
  :content
  [{:type :strong, :content [{:type :text, :text "Threshold 1: (~"
                              {:type :formula, :text "125K"}}]}
   {:type :text, :text " - $240K/quarter"}]}]

So the :strong should wrap the formula? If you agree I can look into this @mk @zampino

[borkdude]

And if we fix this, the above workaround can still work (which I forgot to mention as the main point I was trying to make).

[borkdude]

Made a proposal PR to nextjournal.markdown here:

nextjournal/markdown#56

[borkdude]

@kennyjwilli PR in #780

Will finish it next week, but you can probably start testing it. Feedback welcome.