clojure.core.logic/featurec

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Type: function Added: Clojure unknown Examples: 3 Runnable: 0

([x fs])

Ensure that a map contains at least the key-value pairs in the map fs. fs must be partially instantiated - that is, it may contain values which are logic variables to support feature extraction.

Examples

by qneo on 2015-12-20 . May have evaluation errors. ▶

(run 1 [q] (featurec q {1 2}) (== q {2 4})) () ;; {2 4} does not cointain k-v 1 2 (run 1 [q] (featurec q {1 2}) (== q {1 2 2 4})) ({1 2, 2 4}) ;; {1 2 2 4} does contain k-v 1 2

by freckletonj on 2016-04-13 . May have evaluation errors. ▶

;; http://michaelrbernste.in/2013/05/12/featurec-and-maps.html ;; http://stackoverflow.com/questions/15821718/how-do-i-de-structure-a-map-in-core-logic (is (= (run* [q] (featurec q {:foo 1}) (== q {:foo 1 :bar 2})) '({:foo 1 :bar 2})))

by owenRiddy on 2020-08-04 . May have evaluation errors. ▶

;; ;; Using featurec rather than == can trigger bugs. ;; (run* [p] (featurec p {:a 1}) (fresh [m] (== p {:a m}))) ;; => Error printing return value (IllegalArgumentException) at ;; => clojure.lang.RT/seqFrom (RT.java:557). ;; => Don't know how to create ISeq from: java.lang.Long (run* [p] (== p {:a 1}) (featurec p {:a 1}) (fresh [m] (== p {:a m}))) ;; => ({:a 1})

See also

• clojure.core.logic/conjo

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