LaTeX: ranges of SI units disappear during conversion

[efharkin]

Description of bug and steps to reproduce

As of the current master (7c6dbd3) ranges of SI units provided by \SIRange{firstvalue}{secondvalue}{unit} of siunitx are dropped during parsing of LaTeX files. This leads to funny conversions like the following:

Original LaTeX test_sirange.tex

Something important is happening \SIRange{100}{200}{\ms} after the event.

Expected output in markdown

Something important is happening 100 ms to 200 ms after the event.

Actual output of pandoc -so test_sirange.md test_sirange.tex

Something important is happening after the event.

Why is this a bug?

The manual states that pandoc doesn't aim for perfect document conversion, and that in particular formatting details may not be preserved across formats. However, by dropping \SIRange, pandoc's output can become semantically different from the original LaTeX (ie phrases might not make sense or even take on a different meaning after conversion), so this isn't a formatting detail.

Proposed fix

siunitx's \SIRange is highly configurable. Depending on the options used, \SIRange{100}{200}{\ms} might be rendered as

• 100 ms to 200 ms
• 100 ms – 200 ms
• 100 – 200 ms
• etc

In the spirit of prioritizing semantics over formatting details, I think it would be good enough for pandoc to support only the first option. I've implemented this approach and will submit a PR shortly.

Related issues and PRs

How pandoc should parse siunitx commands has also been discussed in issue #3587. I'm opening a new issue because that issue (and the associated PR #3823) have been focused on the \num command and are a bit stale.

[efharkin]

Implemented a fix here #6418.

[tarleb]

Closing, as the fix was merged last year. (Thanks!)