Philip Kaludercic wrote:

Spyros Roum <spyros.roum@posteo.net> writes:

Juri Linkov wrote:

I'm trying to get the compile prompt to suggest completion based on past
commands I've run.

You can use 'C-x <up>' in the compile prompt to complete on past commands.

This is indeed a lot closer to what I want, however it still lacks a
lot of things compared to my solution.

Unless there is some package/mode I don't know about, It's a lot less
dynamic, for instance I can't keep typing to reduce
possible items.

One should keep in mind that completion is not the same as narrowing.
The former expands substrings, while the latter is more like a system
for selecting an option from a list, that usually comes with some query
system.
              
Confusing these two can lead to uncomfortable edge-cases for both sides,
and sadly a lot of packages assume that completing-read is the same as a
hypothetical selecting-read.

I was 100% confusing these two, thanks for clearing it up.
To make sure I understand correctly, when using `completing-read` to read user input, that is narrowing,
while the `C-x <up>` and *Completions* buffer is completion. And from this thread I learned that Icicles can be used to enhance completion
similarly to how narrowing frameworks (like vertico) enhance narrowing.

My solution can leverage all of vertico and friend, and in general
provides an experience that's the same as other minibuffer prompts,
like M-x.

But for someone like me who doesn't use a selecting-narrowing framework
like vertico, it suddenly means that SPC is rebound to
`minibuffer-complete-word' and entering new commands becomes *a lot* more
cumbersome.

And this is where the user option for the function would come in useful.