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by fiddlosopher 157 days ago
Pandoc does know how to expand LaTeX macros. For example, given the LaTeX

  \newcommand{\pair}[2]{\langle #1, #2\rangle}
  $$\pair{a^2}{\frac{\pi}{2}}$$
pandoc will give you the Typst

  $ chevron.l a^2 \, pi / 2 chevron.r $
which is correct. Tylax, on the other hand, seems to have problems with this example, producing

  $ angle.l^()frac(pi,)angle.r  $
which does not compile with typst. Going the other direction, pandoc also understands typst scripting. For example, from

  #let count = 8
  #let nums = range(1, count + 1)
  #let fib(n) = (
    if n <= 2 { 1 }
    else { fib(n - 1) + fib(n - 2) }
  )

  The first #count numbers of the sequence are:

  #align(center, table(
    columns: count,
    ..nums.map(n => $F_#n$),
    ..nums.map(n => str(fib(n))),
  ))
pandoc produces this LaTeX:

  The first 8 numbers of the sequence are:

  {\def\LTcaptype{none} % do not increment counter
  \begin{longtable}[]{@{}llllllll@{}}
  \toprule\noalign{}
  \endhead
  \bottomrule\noalign{}
  \endlastfoot
  \(F_{1}\) & \(F_{2}\) & \(F_{3}\) & \(F_{4}\) & \(F_{5}\) & \(F_{6}\) &
  \(F_{7}\) & \(F_{8}\) \\
  1 & 1 & 2 & 3 & 5 & 8 & 13 & 21 \\
  \end{longtable}
  }
With the same input, Tylax produces:

  The first 8 numbers of the sequence are:

  \begin{center}

  \begin{tabular}{|c|}
  \hline
  \hline
  \end{tabular}\end{center}
which is just an empty table.
1 comments

You are absolutely right. Thank you for pointing this out! Regarding your questions: 1. The `\pair` issue: This is definitely a bug. My macro expander is based on text replacement and obviously cannot handle nested parameters. I will fix the recursive logic. 2. The `fib` loop: Pandoc seems to use `typst-hs`, which contains a complete Typst evaluator. Tylax is strictly designed as a static AST transformer. We haven't implemented the Typst virtual machine, so loops or recursive functions cannot be executed. This will be gradually improved later to make it more usable; my claim of "better macro support" was clearly premature. This was a big mistake on my part, and we will strive to achieve this goal in future updates! Thank you very much for your feedback and for pointing out the bug!