Implement ability to pipe structured output of ALEFindReferences to other programs

[dsifford]

See https://github.com/w0rp/ale/issues/2210#issuecomment-456181296

For me personally, I'd want to pipe the output to be handled by fzf. See here for some examples as to how someone might go about that.

[terkelg]

I would love to have this too!

[sliminality]

This would be great, especially the ability to use the fzf preview window to see more context surrounding the reference.

It looks like the desired approach is to

add a public function which accepts a callback function for handling the results.

I'm new to this plugin's codebase, where would this function be added?

[karangb]

This would be great! I wonder if there is a temporary way to achieve this while this issue is open

[bretello]

@karangb my current workaround, although it's no substitute for a lsp-provided reference search, is the following:

nnoremap K :exe "Rg  " . expand("<cword>")<cr>

Hitting K over a word will open up a ripgrep (:Rg) search for the word under the cursor

[bretello]

Ended up hacking an implementation over at #5018