Fix auto-insertion of spaces in paredit

[yuhan0]

Fixes #565

The first 3 commits should be squashed together, I just found the original function hard to understand and had to refactor it along the way and then remove what seemed like uneccessary checks.

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[bbatsov]

Because without it this code would be applied to any mode where paredit is enabled.

[yuhan0]

Ah, I thought it was a mode local variable - will add it back in.

[yuhan0]

Actually, wouldn't it make more sense to do (make-local-variable 'paredit-space-for-delimiter-predicates) inside clojure-paredit-setup rather than add global predicates?

[bbatsov]

I guess that's an option as well.

[bbatsov]

I get the point of using this macro here, but probably we need some alias for it, otherwise the tests read a bit weird. Probably not a big deal, though, as I can't suggest a great name right now - something like with-edits/actions.

[yuhan0]

I couldn't think of a name as well, but at least the console output makes sense -

Interactions with Paredit:
  it should insert a space
    before lists (0.19ms)
    before vectors (0.17ms)
    before maps (0.16ms)
    before strings (0.15ms)
    after gensym (0.20ms)
    after symbols ending with ' (0.19ms)
  it should not insert a space
    for anonymous fn syntax (0.19ms)
    for hash sets (0.17ms)
    for regexes (0.16ms)
    for quoted collections (0.17ms)
    for reader conditionals (0.17ms)

[yuhan0]

I did some more refactoring, realising that the other function clojure-no-space-after-tag was mostly repeated logic, and could be folded into a single predicate.

clojure--collection-tag-regexp doesn't seem to be used elsewhere so I made it obsolete too.
Side note: it also had the bug of using a naive "[a-zA-Z0-9]" regex which does not adequately describe clojure symbols. I noticed a few other regexes in the file which have a similar issue, but that's probably best left for another PR

[yuhan0]

Also I'm not a Paredit user myself (which is why this issue originally went unnoticed), so it would be great if someone could help test these changes out!

[bbatsov]

I noticed a few other regexes in the file which have a similar issue, but that's probably best left for another PR

Agreed.

Also I'm not a Paredit user myself (which is why this issue originally went unnoticed), so it would be great if someone could help test these changes out!

I guess you're into smartparens or lispy, right? Given the unit tests I'm reasonably confident with your changes, so I'll just merge them and see what feedback we'll get. I'm using paredit, but I guess I don't update my Emacs packages often enough if I didn't notice this myself. :D