circular-buffer

An implementation of persistent circular buffer. Implements most of Clojure collections interfaces (and therefore supports methods like conj, into, nth, etc) as well as Java collections interfaces.

The implementation provides the following options:

• :type - defines the type of values, that will be stored in the buffer and therefore the type of the structure that backs the buffer (either clojure.core.Vec or clojure.lang.PersistentVector). Possible values are :any :int :long :float :double :byte :short :char or :boolean. Default: :any

• :default - defines the default value in the buffer. If omitted depends on the type of values for which the buffer is configured. Default: nil, 0, 0.0 or false

• :direction - defines the direction in which new elements are added into the buffer. Default: :left

Usage

Include the library in your leiningen project dependencies:

[circular-buffer "0.1.0-SNAPSHOT"]

Examples

(use 'hamakar.circular-buffer)

; defines a new circular buffer of size 5
(def cb-left (cbuf 5)) ; #'hamakar.circular-buffer/cb-left

cb-left ; [nil nil nil nil nil]

(conj cb-left 4) ; [nil nil nil nil 4]

(into cb-left [1 2 3 4 5 6 7 8]) ; [4 5 6 7 8]

(subvec (into cb-left [1 2 3 4 5 6 7 8]) 2) ; [6 7 8]

(def cb-left (cbuf 4 :type :int :default -1)) ; #'hamakar.circular-buffer/cb-left

cb-left ; [-1 -1 -1 -1]

(def cb-right (into (cbuf 4 :direction :right) [1 2 3 4])) ; #'hamakar.circular-buffer/cb-right

cb-right ; [4 3 2 1]

(pop cb-right) ; [3 2 1 nil]

(peek cb-right) ; 4

(= cb-right (list 4 3 2 1)) ; true

(nth cb-right 0) ; 4

License

Copyright © 2013 Pavel Prokopenko

Distributed under the Eclipse Public License, the same as Clojure.