cider-prettify-sexp

[gtrak]

<devn> anyone know if there's a way to reformat something like '({:a 1 ...} {:b 2 ...} ...} like how clojure.pprint would print it?
<devn> for emacs?
<gtrak> devn: might be a good idea for a cider middleware
<gtrak> I end up reformatting edn manually a lot.. would be nice to select it and M-x cider-prettify-sexp or something
<arrdem> I'd throw money at a cider pprint middleware...

[arrdem]

👍

[bbatsov]

Sounds like a good idea.

[dgtized]

cider-pprint-eval-last-sexp, and cider-pprint-eval-defun-at-point appear to partially do this. In a cider minor mode enabled buffer these are bound to C-c C-p and C-c C-f respectively. Would it make sense to bind C-c C-f to cider-pprint-eval-defun-at-point in the repl? C-c C-p is not available as it is used to move to previous prompt.

Unfortunately both of these functions are a little odd to use, since it's always evaluating the form. If the form can't evaluate (as is the case in unquoted lists in output), it throws an error. For the case above it is quoted, but it seems like a generic method for pretty print replacing without evaluating would be really useful for the edn case. Then again, I'm not sure how to deal with #inst and friends.

[bbatsov]

I'm pretty sure the point of the issue is to reformat structures in the source code, instead of simply pretty-printing them somewhere.

[dgtized]

Yea, I gathered that. So my though on that is that currently cider-pprint-eval-* do not have a prefix argument, so one approach would be to override that ala cider-eval-last-sexp, so it prints after on one prefix argument. I'm wondering if the 'replace at point' functionality for both could be a second prefix argument? That or maybe prefix argument to cider-eval-last-sexp-and-replace?

The reason I talked about the problems with evaluating the form is that is part of the problem with this approach. For a reformat case, lists should probably be quoted automatically and not evaluated. I'm also not quite clear how to grab the stdout of pprint instead of the eval result.