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
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
Also aliased as: intersection
<<(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
def ^(enum)
  n = self.class.new(enum)
  each { |o| n.include?(o) ? n.delete(o, 1) : n.add(o) }
  n
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
def add(o)
  @hash[o] ||= 0
  @hash[o] += 1
  self
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
def cardinality
  @hash.inject(0) { |s, (e, m)| s += m }
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
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
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
def delete_if
  each { |o| delete(o) if yield(o) }
  self
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
def each
  @hash.each_pair do |key, multiplicity|
    multiplicity.times do
      yield(key)
    end
  end
  self
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
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
Also aliased as: ==
intersection(enum) click to toggle source
Alias for: &
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
def merge(enum)
  enum.each { |o| add(o) }
  self
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
def multiplicity(e)
  @hash[e]
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
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
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
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
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
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
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
def subtract(enum)
  enum.each { |o| delete(o, 1) }
  self
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
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
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
def to_a
  inject([]) { |ary, (key, _)| ary << key }
end

[Validate]

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