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favila/safe-merge.clj

Created February 28, 2020 22:11
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merge, but throws on conflicts
Raw
safe-merge.clj
(defn safe-merge
"Like merge, but throws if maps have the same keys but different values."
[& maps]
(reduce
(fn [m [m2k m2v :as re]]
(if-some [[_ mv :as le] (find m m2k)]
(if (= mv m2v)
m
(throw (ex-info "Attempted to safe-merge maps with conflicting entries"
{:left-entry le :right-entry re})))
(conj m re)))
(first maps) (apply concat (rest maps))))
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