Fix nested :inner specs

[camsaul]

Fixes #349

After spending a few hours trying to figure out the best way to solve this problem without changing too much stuff I decided to changed the indent order code as follows:

• specs with multiple parts like [[:block 1] [:inner 1]] now get compiled to separate indenters for each part of the spec e.g. one for [:block 1] and one for [:inner 1]
• :inner specs with depth greater than zero are sorted preferentially with deeper depths sorted first.

Previously in #349 the sorted-indents here

cljfmt/cljfmt/src/cljfmt/core.cljc

Line 384 in d84bd41

sorted-indents (sort-by indent-order indents)

would have looked like

[[my.namespace/with-x [[:block 0]]]
 [extend-protocol [[:block 1] [:inner 1]]]

This PR changes them so they now look like

[[extend-protocol [[:inner 1]]
 [my.namespace/with-x [[:block 0]]]
 [extend-protocol [[:block 1]]]

This ensures nested :inner indenters take precedence over general top-level indenters and defprotocol/extend-protocol/etc. are applied in a sane way.

[weavejester]

What's the advantage of splitting up the indentation rules, compared to fixing the indentation ordering to prefer more 'outer' indentations?

[camsaul]

Originally I thought keeping them as one rule it would potentially break stuff in weird edge cases , e.g. if you have

letfn [[:block 0] [:inner 1]]
my.namespace/letfn [[:block 0]]

the stuff at depth one inside a my.namespace/letfn could be getting formatted as [:inner 1] but now that I squint at it a bit, it's a) a separate issue, b) splitting the rules up doesn't fix the problem, and c) a really contrived issue anyway.

I updated the PR so it keeps things as one rule and only updates the indent-order function

[weavejester]

Thanks for the PR. I only had one small suggestion around readability.

[weavejester]

Perhaps instead:

(defn- indent-order [[key specs]]
  (let [get-depth (fn [[type depth]] (if (= type :inner) depth 0))
        max-depth (transduce (map get-depth) max 0 specs)
        key-order  (cond
                    (qualified-symbol? key) 0
                    (simple-symbol? key)    1
                    (pattern? key)          2)]
    [(- max-depth) key-order (str key)]))

[camsaul]

done

[weavejester]

Thanks for the update, and apologies for the delay in reviewing it. This past month has been rather busy for me.