[Fix #610] Treat all paren lists as data in edn-mode

In EDN files there are no function calls, so paren lists like
(:key1 :value1 :key2 :value2) should use data-style indentation
(aligned at column 1 inside the paren) rather than function-call
style indentation.

Add `(derived-mode-p 'edn-mode)` as the first check in
`clojure--not-function-form-p` so that all list forms in EDN
buffers are treated as data.

Also fix indentation of a seq-find call to satisfy the linter.

Author: bbatsov

clojure-mode.el

@@ -1725,7 +1725,8 @@ accepted by `clojure-indent-style'."
 
 (defun clojure--not-function-form-p ()
   "Non-nil if form at point doesn't represent a function call."
-  (or (member (char-after) '(?\[ ?\{))
+  (or (derived-mode-p 'edn-mode)
+      (member (char-after) '(?\[ ?\{))
       (save-excursion ;; Catch #?@ (:cljs ...)
         (skip-chars-backward "\r\n[:blank:]")
         (when (eq (char-before) ?@)

test/edn-mode-indentation-test.el

@@ -56,22 +56,27 @@
     (it "should align let arguments instead of using body indentation"
       (with-edn-buffer "\n(let [x 1]\nx)"
         (indent-region (point-min) (point-max))
-        (expect (buffer-string) :to-equal "\n(let [x 1]\n     x)")))
+        (expect (buffer-string) :to-equal "\n(let [x 1]\n x)")))
 
     (it "should align if arguments instead of using body indentation"
       (with-edn-buffer "\n(if true\n1\n2)"
         (indent-region (point-min) (point-max))
-        (expect (buffer-string) :to-equal "\n(if true\n    1\n    2)")))
+        (expect (buffer-string) :to-equal "\n(if true\n 1\n 2)")))
 
     (it "should align cond arguments instead of using body indentation"
       (with-edn-buffer "\n(cond a\nb)"
         (indent-region (point-min) (point-max))
-        (expect (buffer-string) :to-equal "\n(cond a\n      b)")))
+        (expect (buffer-string) :to-equal "\n(cond a\n b)")))
 
     (it "should align do arguments instead of using body indentation"
       (with-edn-buffer "\n(do a\nb)"
         (indent-region (point-min) (point-max))
-        (expect (buffer-string) :to-equal "\n(do a\n    b)"))))
+        (expect (buffer-string) :to-equal "\n(do a\n b)")))
+
+    (it "should align keyword lists as data (issue #610)"
+      (with-edn-buffer "\n(:key1 :value1\n:key2 :value2)"
+        (indent-region (point-min) (point-max))
+        (expect (buffer-string) :to-equal "\n(:key1 :value1\n :key2 :value2)"))))
 
   (describe "maps, vectors, and sets indent normally"