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Support list/xs-distinct-by?

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Supporting a predicate to check that all elements in a list are distinct after
applying a transformation function to them.
This commit is contained in:
William Carroll 2020-02-14 15:34:56 +00:00
parent 3677a7a39e
commit fa779ab7bf
1 changed files with 5 additions and 0 deletions
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5
emacs/.emacs.d/wpc/list.el
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@ -199,6 +199,11 @@ Be leery of using this with things like alists. Many data structures in Elisp
"Return t if X is in XS using `equal'."
(-contains? xs x))
(defun list/xs-distinct-by? (f xs)
"Return t if all elements in XS are distinct after applying F to each."
(= (length xs)
(->> xs (-map f) set/from-list set/count)))
;; TODO: Support dedupe.
;; TODO: Should we call this unique? Or distinct?