Add paredit setup for edn-mode

[grzm]

Like clojure-mode, edn-mode needs to coax paredit to auto-pair curly braces.

I've replicated the minimum set of features from the existing clojure-paredit-setup to edn-paredit-setup to allow auto-pair functionality for curly braces ({)

I tried to a test to confirm the behavior, but my emacs/buttercup testing skills aren't currently up to the task. Here's what I (naïvely) tried (added to edn-mode-indentation-test.el for experimentation).

(require 'paredit)

(describe "edn-mode paredit support"
          (describe "auto-pairs curly braces"
                    (it "should add a closing brace with an opening brace is inserted"
                        (with-edn-buffer ""
                                         (paredit-mode)
                                         (insert "{")
                                         (expect (buffer-string) :to-equal "{}")))))

---

Before submitting a PR mark the checkboxes for the items you've done (if you
think a checkbox does not apply, then leave it unchecked):

• The commits are consistent with our contribution guidelines.
• [-] You've added tests (if possible) to cover your change(s). Bugfix, indentation, and font-lock tests are extremely important!
• You've run M-x checkdoc and fixed any warnings in the code you've written.
• You've updated the changelog (if adding/changing user-visible functionality).
• [n/a] You've updated the readme (if adding/changing user-visible functionality).

Thanks!

[bbatsov]

Thanks for the PR! The problem diagnosis is correct — edn-mode-map has prog-mode-map as parent, not clojure-mode-map, so the paredit {/} bindings from clojure-paredit-setup don't reach EDN buffers.

However, I think we can fix this without duplicating the setup function. The root cause is that clojure-paredit-setup defaults to clojure-mode-map when no keymap is passed. If we change it to default to (current-local-map) instead, the existing paredit-mode-hook (which edn-mode already inherits from clojure-mode) will just work for all derived modes automatically.

Something like:

(let ((keymap (or keymap (current-local-map))))

That single-line change should fix EDN mode (and any future derived modes) without needing edn-paredit-setup at all.

[grzm]

That's the knowledge your years of emacs-lisp experience provides :) Thanks for explaining. I've updated the patch as suggested. (And thanks for your patience!)

[bbatsov]

You should also add a "Bugs Fixed" heading for this entry.

[bbatsov]

Don't forget to update the docstring above as well. (it still mentions clojure-mode-map as the default)

[grzm]

It's not clear to me why the windows-latest and ubuntu-latest/snapshot CI checks are failing when the others are still passing and the error messages are inscrutable to my naïve eyes. Any hints as to what might be going on?

[bbatsov]

Don't worry, that's not related to your changes. Thanks!

[grzm]

Thanks!