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gfredericks/reconstitutible-iterate.clj

Created March 17, 2012 17:44
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Reconstitutible Iterate
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reconstitutible-iterate.clj
(ns lib-2289.core
(:refer-clojure :exclude [iterate]))
(defprotocol IReconstitutible
(reconstitute [self]))
(extend-type clojure.lang.LazySeq
IReconstitutible
(reconstitute [self]
(reconstitute (.seq self))))
(deftype IterateSeq [f f-form ob]
clojure.lang.Seqable
(seq [self] self)
clojure.lang.ISeq
(first [self] ob)
(next [self] (new IterateSeq f f-form (f ob)))
(more [self] (new IterateSeq f f-form (f ob)))
(cons [self item]
(cons item self))
IReconstitutible
(reconstitute [self]
(list 'iterate f-form ob)))
(defmacro iterate
[f ob]
`(new IterateSeq ~f '~f ~ob))
;; user> (->> (iterate (partial + 7) 18) (drop 82484) reconstitute)
;; (iterate (partial + 7) 577406)
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