Multiset implements a collection of unordered values and allows duplicates.
require 'multiset' s1 = Multiset.new [1, 2] # -> #<Multiset: {1, 2}> s1.add(2) # -> #<Multiset: {1, 2, 2}> s1.merge([2, 6]) # -> #<Multiset: {1, 2, 2, 2, 3}> s1.multiplicity(2) # -> 3 s1.multiplicity(3) # -> 1
Returns a new set containing elements common to the set and the given enumerable object.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 129 def &(enum) s = dup n = self.class.new enum.each { |o| if s.include?(o) s.delete(o, 1) n.add(o) end } n end
Returns a new set containing elements exclusive between the set and the given enumerable object. (set ^ enum) is equivalent to ((set | enum) - (set & enum)).
# File lib/rack/mount/vendor/multimap/multiset.rb, line 145 def ^(enum) n = self.class.new(enum) each { |o| n.include?(o) ? n.delete(o, 1) : n.add(o) } n end
Adds the given object to the set and returns self. Use merge
to add many elements at once.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 80 def add(o) @hash[o] ||= 0 @hash[o] += 1 self end
Returns the total number of elements in a multiset, including repeated memberships
# File lib/rack/mount/vendor/multimap/multiset.rb, line 27 def cardinality @hash.inject(0) { |s, (e, m)| s += m } end
Deletes all the identical object from the set and returns self. If
n
is given, it will remove that amount of identical objects
from the set. Use subtract
to delete many different items at
once.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 93 def delete(o, n = nil) if n @hash[o] ||= 0 @hash[o] -= n if @hash[o] > 0 @hash.delete(o) if @hash[o] == 0 else @hash.delete(o) end self end
Deletes every element of the set for which block evaluates to true, and returns self.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 108 def delete_if each { |o| delete(o) if yield(o) } self end
Calls the given block once for each element in the set, passing the element as parameter. Returns an enumerator if no block is given.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 69 def each @hash.each_pair do |key, multiplicity| multiplicity.times do yield(key) end end self end
Returns true if two sets are equal. Two multisets are equal if they have the same cardinalities and each element has the same multiplicity in both sets. The equality of each element inside the multiset is defined according to Object#eql?.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 155 def eql?(set) return true if equal?(set) set = self.class.new(set) unless set.is_a?(self.class) return false unless cardinality == set.cardinality superset?(set) && subset?(set) end
Merges the elements of the given enumerable object to the set and returns self.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 115 def merge(enum) enum.each { |o| add(o) } self end
Returns the number of times an element belongs to the multiset.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 21 def multiplicity(e) @hash[e] end
Returns true if the set is a proper subset of the given set.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 60 def proper_subset?(set) set.is_a?(self.class) or raise ArgumentError, "value must be a set" return false if set.cardinality <= cardinality all? { |o| multiplicity(o) <= set.multiplicity(o) } end
Returns true if the set is a proper superset of the given set.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 46 def proper_superset?(set) set.is_a?(self.class) or raise ArgumentError, "value must be a set" return false if cardinality <= set.cardinality set.all? { |o| set.multiplicity(o) <= multiplicity(o) } end
Returns true if the set is a subset of the given set.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 53 def subset?(set) set.is_a?(self.class) or raise ArgumentError, "value must be a set" return false if set.cardinality < cardinality all? { |o| multiplicity(o) <= set.multiplicity(o) } end
Deletes every element that appears in the given enumerable object and returns self.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 122 def subtract(enum) enum.each { |o| delete(o, 1) } self end
Returns true if the set is a superset of the given set.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 39 def superset?(set) set.is_a?(self.class) or raise ArgumentError, "value must be a set" return false if cardinality < set.cardinality set.all? { |o| set.multiplicity(o) <= multiplicity(o) } end
Converts the set to an array. The order of elements is uncertain.
# File lib/rack/mount/vendor/multimap/multiset.rb, line 34 def to_a inject([]) { |ary, (key, _)| ary << key } end