clojure.core/seqable?

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Type: function Added: Clojure 1.9 Examples: 2 Runnable: 0

([x])

Return true if the seq function is supported for x

Examples

by svenschoenung on 2017-05-24 . May have evaluation errors. ▶

;;;; nil is seqable (seqable? nil) ;;=> true ;;;; Anything that implements CharSequence is seqable (seqable? "") ;;=> true (seqable? (java.lang.StringBuilder.)) ;;=> true (seqable? (java.lang.StringBuffer.)) ;;=> true ;;;; Anything that implements Seqable is seqable (seqable? []) ;;=> true (seqable? {}) ;;=> true (seqable? #{}) ;;=> true (seqable? '()) ;;=> true (seqable? (lazy-seq)) ;;=> true ;;;; Anything that implements Iterable is seqable (seqable? (java.util.ArrayList.)) ;;=> true (seqable? (java.util.HashMap.)) ;;=> true (seqable? (java.util.HashSet.)) ;;=> true ;;;; Arrays are seqable (seqable? (int-array 5 1)) ;;=> true (seqable? (double-array 5 1.0)) ;;=> true (seqable? (char-array 5 \c)) ;;=> true ;;;; Some stuff that isn't seqable (seqable? true) ;;=> false (seqable? \c) ;;=> false (seqable? 1) ;;=> false (seqable? 1.0) ;;=> false (seqable? (fn f [])) ;;=> false

by tomdl89 on 2024-02-01 . May have evaluation errors. ▶

;; All collections that return true for coll? return true for seqable? (every? coll? [() [] #{} {} (clojure.lang.PersistentQueue/EMPTY)]) ;; => true (every? seqable? [() [] #{} {} (clojure.lang.PersistentQueue/EMPTY)]) ;; => true ;; But some collections which are not persistent, are still seqable… (some coll? [(int-array [4 5 6]) (java.util.ArrayList.) (java.util.HashMap.)]) ;; => nil (every? seqable? [(int-array [4 5 6]) (java.util.ArrayList.) (java.util.HashMap.)]) ;; => true ;; And there are some collections which aren't even directly seqable… (seqable? (java.nio.IntBuffer/allocate 4)) ;; => false ;; But there's usually a way to get there… (seqable? (.array (java.nio.IntBuffer/allocate 4))) ;; => true

See also

• clojure.core/seq (5)
• clojure.core/seq? (2)

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