Feature request: flexibly-generated workspace in worksheets (like \vfill)

[rhinopotamus]

While I'm filing issues about worksheets, here's another one that'd be nice.

It's idiomatic in LaTeX to use multiple \vfills to generate workspace. For instance:

\begin{enumerate}
    \item This task will have some workspace. 
    \vfill
    \item This task will have twice as much workspace as the first one.
    \vfill
    \vfill
    \item This task doesn't need workspace because I'm asking you to fill in a graph and providing graph paper:
    
    \includegraphics[width=0.75\textwidth]{GraphPaper.png}
\end{enumerate}

This is an elegant solution because you don't have to specify the amount of space you want in absolute terms, just relative to the other spaces on the page. What's more, if you decide that you want that graph paper to be a bit bigger (maybe 0.9\textwidth) or a bit smaller (maybe 0.5\textwidth), all the workspace automatically reflows sensibly.

It'd be neat if this behavior could be reproduced within PreTeXt worksheets, which is the only context where we're acknowledging the primacy of printed output.

I wonder if some of the same width logic in <sidebyside> could be repurposed.

[davidfarmer]

At some point we did have support for relative spacing of the answer space.
That is: you specify the relative sizes of each answer space.

I am not sure if that is still implemented, but I will try to check.

[rbeezer]

Perhaps by popular request, they seem to be given in absolute terms.

[Alex-Jordan]

I argued for absolute sizing with vertical workspace in a worksheet. I gave two arguments.

• The purpose is to give a reader/student enough space to do some work. An author can judge if 2 inches is enough. They cannot judge if some percent of available space is enough until they see the output. And even then, if a publisher changes their page geometry, you could easily end up not giving enough space.
• A percent/proportion of available space is not actually an attribute of an exercise. It has no meaning in the context of an exercise. It only has meaning in the context of all the other exercises/content on that page.

However, the intent is that you give an absolute size that is to be interpreted as a minimum. We are supposed to then have spacing mechanisms in place that allow that space to grow (using something like \vfill) to spread out any excess better.

If that is working, and an author really does not want to specify absolute vertical space sizes, the author could use very small sizes like 1mm and it should behave much like there is one \vfill in each of the workspaces. Not the same as using N \vfill here and M \vfill there, but that is what I think is the state of affairs. (Without checking in on things... just based on memory.)