LaTeX: Support for Subfigure Package

[schrieveslaach]

Many scientific papers include subfigures. For example:

\begin{figure}[ht]
    \begin{subfigure}{0.45\textwidth}
        \includegraphics{img1.jpg}
        \caption{Catpion 1}
    \end{subfigure}
    
    \begin{subfigure}{0.45\textwidth}
        \includegraphics{img2.jpg}
        \caption{Catpion 2}
    \end{subfigure}
    \caption{Subfigure with Subfloat}
\end{figure}

Pandoc should produces two figures nested in a outer figure.

<figure>
<figure>
<img src="img1.jpg" alt="Catpion 1" /><figcaption>Catpion 1</figcaption>
</figure>
<figure>
<img src="img2.jpg" alt="Catpion 2" /><figcaption>Catpion 2</figcaption>
</figure>
<figcaption>Subfigure with Subfloat</figcaption>
</figure>

[jgm]

Pandoc's internal document model doesn't currently have a dedicated block element for figures. We use the hack of treating images that are by themselves in a paragraph, with a title beginning fig:, as figures.

Going forward it would be good to have a dedicated Figure block element. See #3177.

Without better support for figures in the AST, the best we could do with subfigures would be to parse them as a sequence of figures.

[schrieveslaach]

Thanks for the clarification. Currently, a sequence of figures is sufficient for my needs. I assume, that you are already working on this?

I'm trying to fix the caption problem. I think it has something to do with the setCaption and resetCaption and addImageCaption. In an imperative programming language I would use a stack to solve this. Do you have any ideas to solve this in haskell?

[tarleb]

Sorry, typo in commit.

[jgm]

I'm trying to fix the caption problem. I think it has something to do with the setCaption and resetCaption and addImageCaption. In an imperative programming language I would use a stack to solve this. Do you have any ideas to solve this in haskell?

@schrieveslaach What currently happens with the above example when you run the code in your PR?
Just eyeballing it, I don't see why captions would be messed up.

[schrieveslaach]

@jgm, The outer caption will be used twice:

<figure>
<img src="img1.jpg" alt="Subfigure with Subfloat" /><figcaption>Subfigure with Subfloat</figcaption>
</figure>
<figure>
<img src="img2.jpg" alt="Subfigure with Subfloat" /><figcaption>Subfigure with Subfloat</figcaption>
</figure>

I would expect at least following output.

<figure>
<img src="img1.jpg" alt="Subfigure with Subfloat" /><figcaption>Caption 1</figcaption>
</figure>
<figure>
<img src="img2.jpg" alt="Subfigure with Subfloat" /><figcaption>Caption 2</figcaption>
</figure>

Ideally, the third caption should be placed below:

<figure>
<img src="img1.jpg" alt="Subfigure with Subfloat" /><figcaption>Caption 1</figcaption>
</figure>
<figure>
<img src="img2.jpg" alt="Subfigure with Subfloat" /><figcaption>Caption 2</figcaption>
</figure>
<figcaption>Subfigure with Subfloat</figcaption>

[jgm]

I found a solution.