Parent

Multiset

Multiset implements a collection of unordered values and allows duplicates.

Example

  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

Public Instance Methods

&(enum) click to toggle source

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
129:   def &(enum)
130:     s = dup
131:     n = self.class.new
132:     enum.each { |o|
133:       if s.include?(o)
134:         s.delete(o, 1)
135:         n.add(o)
136:       end
137:     }
138:     n
139:   end
<<(o) click to toggle source
Alias for: add
==(set) click to toggle source
Alias for: eql?
^(enum) click to toggle source

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
145:   def ^(enum)
146:     n = self.class.new(enum)
147:     each { |o| n.include?(o) ? n.delete(o, 1) : n.add(o) }
148:     n
149:   end
add(o) click to toggle source

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
80:   def add(o)
81:     @hash[o] ||= 0
82:     @hash[o] += 1
83:     self
84:   end
Also aliased as: <<
cardinality() click to toggle source

Returns the total number of elements in a multiset, including repeated memberships

    # File lib/rack/mount/vendor/multimap/multiset.rb, line 27
27:   def cardinality
28:     @hash.inject(0) { |s, (e, m)| s += m }
29:   end
Also aliased as: size, length
delete(o, n = nil) click to toggle source

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
 93:   def delete(o, n = nil)
 94:     if n
 95:       @hash[o] ||= 0
 96:       @hash[o] -= n if @hash[o] > 0
 97:       @hash.delete(o) if @hash[o] == 0
 98:     else
 99:       @hash.delete(o)
100:     end
101:     self
102:   end
delete_if() click to toggle source

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
108:   def delete_if
109:     each { |o| delete(o) if yield(o) }
110:     self
111:   end
each() click to toggle source

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
69:   def each
70:     @hash.each_pair do |key, multiplicity|
71:       multiplicity.times do
72:         yield(key)
73:       end
74:     end
75:     self
76:   end
eql?(set) click to toggle source

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
155:   def eql?(set)
156:     return true if equal?(set)
157:     set = self.class.new(set) unless set.is_a?(self.class)
158:     return false unless cardinality == set.cardinality
159:     superset?(set) && subset?(set)
160:   end
Also aliased as: ==
length() click to toggle source
Alias for: cardinality
merge(enum) click to toggle source

Merges the elements of the given enumerable object to the set and returns self.

     # File lib/rack/mount/vendor/multimap/multiset.rb, line 115
115:   def merge(enum)
116:     enum.each { |o| add(o) }
117:     self
118:   end
multiplicity(e) click to toggle source

Returns the number of times an element belongs to the multiset.

    # File lib/rack/mount/vendor/multimap/multiset.rb, line 21
21:   def multiplicity(e)
22:     @hash[e]
23:   end
proper_subset?(set) click to toggle source

Returns true if the set is a proper subset of the given set.

    # File lib/rack/mount/vendor/multimap/multiset.rb, line 60
60:   def proper_subset?(set)
61:     set.is_a?(self.class) or raise ArgumentError, "value must be a set"
62:     return false if set.cardinality <= cardinality
63:     all? { |o| multiplicity(o) <= set.multiplicity(o) }
64:   end
proper_superset?(set) click to toggle source

Returns true if the set is a proper superset of the given set.

    # File lib/rack/mount/vendor/multimap/multiset.rb, line 46
46:   def proper_superset?(set)
47:     set.is_a?(self.class) or raise ArgumentError, "value must be a set"
48:     return false if cardinality <= set.cardinality
49:     set.all? { |o| set.multiplicity(o) <= multiplicity(o) }
50:   end
size() click to toggle source
Alias for: cardinality
subset?(set) click to toggle source

Returns true if the set is a subset of the given set.

    # File lib/rack/mount/vendor/multimap/multiset.rb, line 53
53:   def subset?(set)
54:     set.is_a?(self.class) or raise ArgumentError, "value must be a set"
55:     return false if set.cardinality < cardinality
56:     all? { |o| multiplicity(o) <= set.multiplicity(o) }
57:   end
subtract(enum) click to toggle source

Deletes every element that appears in the given enumerable object and returns self.

     # File lib/rack/mount/vendor/multimap/multiset.rb, line 122
122:   def subtract(enum)
123:     enum.each { |o| delete(o, 1) }
124:     self
125:   end
superset?(set) click to toggle source

Returns true if the set is a superset of the given set.

    # File lib/rack/mount/vendor/multimap/multiset.rb, line 39
39:   def superset?(set)
40:     set.is_a?(self.class) or raise ArgumentError, "value must be a set"
41:     return false if cardinality < set.cardinality
42:     set.all? { |o| set.multiplicity(o) <= multiplicity(o) }
43:   end
to_a() click to toggle source

Converts the set to an array. The order of elements is uncertain.

    # File lib/rack/mount/vendor/multimap/multiset.rb, line 34
34:   def to_a
35:     inject([]) { |ary, (key, _)| ary << key }
36:   end

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