struct Multiset(T)

• Multiset(T)
• Struct
• Value
• Object

Overview

Multiset implements a collection of unordered elements with duplicates. Also known as Bag.

Multiset uses Hash as storage.

Examples

ms1 = Multiset.new [1, 2]
ms2 = Multiset{2, 1}
ms1 == ms2          # => true
ms1.add(2)          # => Multiset{1, 2, 2}
ms1.merge([2, 6])   # => Multiset{1, 2, 2, 2, 6}
ms1.multiplicity(2) # => 3
ms1.subset? ms2     # => false
ms2.subset? ms1     # => true

Included Modules

• Enumerable(T)
• Iterable(T)

Defined in:

Constant Summary

VERSION = "0.2.0"

Constructors

• .new(enumerable : Enumerable(T))

  returns a new multiset with elements from the given Enumerable

• .new(initial_capacity = nil)

  creates a new empty multiset

Instance Method Summary

• #&(other : Multiset)

  returns a new multiset built by performing multiset intersection with the given Enumerable

• #&(other : Enumerable)
• #*(sf)

  scales the multiplicity of all elements and returns self

• #+(other)

  adds all objects in the given Enumerable to a copy of self

• #-(other : Enumerable)

  returns a new multiset with all elements in given Enumerable removed

• #<<(object : T)

  increments multiplicity of the given Object and returns self

• #==(other : Multiset)

  returns true if both multisets contain the same elements

• #==(other : Set)

  returns true if both sets contain the same elements

• #^(other : Enumerable)

  returns a new multiset built by performing symmetric difference with the given Enumerable

• #|(other : Enumerable)

  returns a new multiset built by performing mutiset union with the given Enumerable

• #add(object : T, count : Int32)

  increments multiplicity of the given Object by count and returns self

• #add(object : T)

  increments multiplicity of the given Object and returns self

• #clear

  removes all elements and returns self

• #delete(object, count : Int32)

  decrements multiplicity of the given Object by count and returns self

• #delete(object)

  decrements multiplicity of the given Object and returns self

• #dup

  returns a duplicate of self

• #each(&)

  calls the given block for each element, yielding the element as a parameter.

• #each

  returns an iterator over each element

• #empty?

  returns true if the multiset has no elements

• #includes?(object)

  returns true if given Object is an element in the multiset

• #inspect(io)

  see #to_s

• #intersects?(other : Multiset)

  returns true if the multiset has any element in common with other

• #merge(elems : Multiset(T))

  adds all elements from the given multiset and returns self

• #merge(elems)

  adds #each element and returns self

• #multiplicity(object : T)

  returns count of the given Object in the multiset

• #multiplicity(object : U) forall U

  returns 0

• #proper_subset?(other : Multiset)

  returns true if the multiset is a proper subset of given multiset

• #proper_superset?(other : Multiset)

  returns true if the multiset is a proper superset of given multiset

• #size

  returns the number of elements

• #subset?(other : Multiset)

  returns true if the multiset is a subset of given multiset

• #subtract(other : Multiset)

  removes all elements in given Enumerable from multiset and returns self

• #subtract(other : Enumerable)
• #superset?(other : Multiset)

  returns true if the multiset is a superset of given multiset

• #to_s(io)

  returns a String representation of the multiset

• #uniq

  returns an Array containing unique elements from the multiset

Constructor Detail

Multiset.new([1, 2, 3, 1]) # => Multiset{1, 1, 2, 3}

ms = Multiset(Int32).new
ms.empty # => true

Instance Method Detail

ms1 = Multiset{1, 1, 1, 2, 2, 3, 4, 5}
ms2 = Multiset{1, 1, 3, 3, 6}
ms3 = Multiset{'a', 1, 1}

ms1 & ms2 # => Multiset{1, 1, 3}
ms1 & ms3 # => Multiset{1, 1}

Multiset{1, 2, 2} * 2 # => Multiset{1, 1, 2, 2, 2, 2}

Multiset{1, 2, 3} + Multiset{3, 4, 5} # => Multiset{1, 2, 3, 3, 4, 5}
Multiset{1, 2, 3} + [3, 4, 5]         # => Multiset{1, 2, 3, 3, 4, 5}

Multiset{1, 2, 3} - [1, 3] # => Multiset{2}

ms = Multiset{1, 2, 3}
ms << 4 # => Multiset{1, 2, 3, 4}

ms1 = Multiset{1, 1, 1, 2, 2, 3, 4, 5}
ms2 = Multiset{1, 1, 3, 3, 6}
ms3 = Multiset{'a', 1, 1}

ms1 ^ ms2 # => Multiset{1, 2, 2, 3, 4, 5, 6}
ms1 ^ ms3 # => Multiset{'a', 1, 2, 2, 3, 4, 5}

ms1 = Multiset{1, 1, 1, 2, 2, 3, 4, 5}
ms2 = Multiset{1, 1, 3, 3, 6}
ms3 = Multiset{'a', 1, 1}

ms1 | ms2 # => Multiset{1, 1, 1, 3, 3, 6, 2, 2, 4, 5}
ms1 | ms3 # => Multiset{'a', 1, 1, 1, 2, 2, 3, 4, 5}

Multiset{4, 5}.add(6, 2) # => Multiset{1, 2, 6, 6}

Multiset{1, 2, 3}.add(4) # => Multiset{1, 2, 3, 4}

Multiset{1, 2, 3}.delete(2) # => Multiset{1, 3}
Multiset{4, 4, 5}.delete(4) # => Multiset{4, 5}

Multiset(Int32).new.empty? # => true
Multiset{1, 2, 3}.empty?   # => false

Multiset{1, 2, 3}.includes?(3)   # => true
Multiset{1, 2, 3}.includes?(4)   # => false
Multiset{1, 2, 3}.includes?('a') # => false

ms = Multiset{3, 4, 5}
Multiset{1, 2, 3}.merge(ms) # => Multiset{1, 2, 3, 3, 4, 5}

ary = [3, 4, 5]
Multiset{1, 2, 3}.merge(ary) # => Multiset{1, 2, 3, 3, 4, 5}

ms = Multiset{1, 2, 2}
ms.multiplicity(1) # => 1
ms.multiplicity(2) # => 2

Mutiset{1, 2}.proper_subset? Multiset{1, 2, 3} # => true
Mutiset{1, 2}.proper_subset? Multiset{1, 1, 2} # => true
Mutiset{1, 2}.proper_subset? Multiset{1, 2}    # => false

Mutiset{1, 2, 3}.proper_superset? Multiset{1, 2} # => true
Mutiset{1, 1, 2}.proper_superset? Multiset{1, 2} # => true
Mutiset{1, 2}.proper_superset? Multiset{1, 2}    # => false

Multiset{1, 2, 3}.size       # => 3
Multiset{1, 1, 1, 2, 3}.size # => 5

Mutiset{1, 2}.subset? Multiset{1, 2, 3} # => true
Mutiset{1, 2}.subset? Multiset{1, 1, 2} # => true
Mutiset{1, 2}.subset? Multiset{1, 2}    # => true

Multiset{1, 2, 3}.subtract([1, 3]) # => Multiset{2}

Mutiset{1, 2, 3}.superset? Multiset{1, 2} # => true
Mutiset{1, 1, 2}.superset? Multiset{1, 2} # => true
Mutiset{1, 2}.superset? Multiset{1, 2}    # => true