Support using stdin for arguments that take files in cross-platform agnostic way

(First of all: yes, I know that Unix-alikes has /dev/stdin that can serve as a file-like standin. That's useless to me when using Windows which lacks such a thing entirely.)

Introduction / Context

Most workflows tend to be born out of necessity. You code something, you make it work, and (assuming they are a regular part of your workflow) you rewrite parts every few months as you come across new requirements or edge cases. That is how I have ended up with a folder of Python scripts that rely on pandoc for a considerable number of manipulations that are mostly quite specific to the scripts themselves. Most of these have accompanying template and/or filter files, but you can imagine that has gotten quite chaotic, especially with some files having become outright abandoned as my needs changed.

Themselves, they are not a pandoc 'problem' at all, but it made me realize that having these parts of the process in separate files is often detrimental a few months down the road in understanding what is actually going on. (I have plenty of comments in my Python code, but those rarely cover the questions I have when something involving pandoc doesn't work quite right!)

Without such means, one way I could 'clean up' this aspect during my upcoming improvement work is by writing a temporary file with the intended filter for every invocation... but that is an unneeded performance hit. Or I could just do nothing at all and keep hating myself every time I have to dig into one of those scripts...

The request

It would be nice if, for commandline arguments that accept a file from the filesystem, there was some sort of cross-platform syntax that would make it read that parameter from standard input.

I realize that there is only one stdin which would limit this functionality to being used in just one argument at a time, but since that covers over half of my script-based pandoc invocations, so it would still make a considerable impact for me personally.

However...

If nobody else sees a use for such a feature, feel free to throw this request in the digital bin. Never before have I been accused of being a user matching the common stereotypes. 😸