multiset

A simple multiset/bag implementation for Clojure.

Usage

Installation via Leiningen

Add this to your :depependencies:

API Docs

The current API docs are here: http://achim.github.io/multiset

Example usage

Define some multisets

user=> (require '[multiset.core :as ms])
nil
user=> (def a (ms/multiset 1 2 4 5 4 2 7))
#'user/a
user=> (def b (ms/multiset 4 5 6 6 9))
#'user/b
user=> (def c (ms/multiset 1 2 4 7))
#'user/c

Basic functionality

user=> a
#{7 5 4 4 2 2 1}
user=> (contains? a 3)
false
user=> (contains? a 2)
true
user=> (disj a 2)
#{7 5 4 4 2 1}
user=> (conj a 4)
#{7 5 4 4 4 2 2 1}
user=> (a 2)

Multiset-specific stuff

user=> (ms/multiset? a)
true
user=> (ms/multiplicities a)
{7 1, 5 1, 4 2, 2 2, 1 1}
user=> (ms/multiplicity a 3)
0
user=> (ms/multiplicity a 2)
2

Multiset operators

user=> (ms/intersect a (conj b 4))
#{5 4 4}
user=> (ms/union a b)
#{1 2 2 4 4 5 6 6 7 9}
user=> (ms/sum a b)
#{1 2 2 4 4 4 5 5 6 6 7 9}
user=> (ms/minus a b)
#{7 4 2 2 1}
user=> (ms/scale a 3)
#{7 7 7 5 5 5 4 4 4 4 4 4 2 2 2 2 2 2 1 1 1}
user=> (ms/cartprod a b)
#{[5 4] [7 6] [7 6] [4 4] [4 4] [5 5] [4 5] [4 5] [5 6] [5 6] [2 4] [2 4] [4 6] [4 6] [4 6] [4 6] [7 9] [2 5] [2 5] [1 4] [2 6] [2 6] [2 6] [2 6] [5 9] [1 5] [4 9] [4 9] [1 6] [1 6] [2 9] [2 9] [1 9] [7 4] [7 5]}
user=> (ms/subset? a b)
false
user=> (ms/subset? c a)
true
user=> (ms/subset? (ms/multiset 2 2 2) a)
false

License

Copyright (C) 2012–2015 Achim Passen and contributors.

Distributed under the Eclipse Public License. See COPYING.