In Files
- set.rb
Parent
Object
Methods
- ::[]
- ::new
- #&
- #+
- #-
- #<
- #<<
- #<=
- #==
- #===
- #>
- #>=
- #^
- #add
- #add?
- #classify
- #clear
- #collect!
- #compare_by_identity
- #compare_by_identity?
- #delete
- #delete?
- #delete_if
- #difference
- #disjoint?
- #divide
- #each
- #empty?
- #filter!
- #flatten
- #flatten!
- #include?
- #initialize_clone
- #initialize_dup
- #inspect
- #intersect?
- #intersection
- #keep_if
- #length
- #map!
- #member?
- #merge
- #proper_subset?
- #proper_superset?
- #reject!
- #replace
- #reset
- #select!
- #size
- #subset?
- #subtract
- #superset?
- #to_a
- #to_s
- #to_set
- #union
- #|
Included Modules
Class/Module Index ![[+]](http://ruby-doc.org/./images/find.png "show/hide quicksearch")
Set
Set implements a collection of unordered values with no duplicates. This is a hybrid of Array's intuitive inter-operation facilities and Hash's fast lookup.
Set is easy to use with Enumerable objects (implementing each). Most of the initializer methods and binary operators accept generic Enumerable objects besides sets and arrays. An Enumerable object can be converted to Set using the to_set method.
Set uses Hash as storage, so you must note the following points:
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Equality of elements is determined according to Object#eql? and Object#hash. Use #compare_by_identity to make a set compare its elements by their identity.
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Set assumes that the identity of each element does not change while it is stored. Modifying an element of a set will render the set to an unreliable state.
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When a string is to be stored, a frozen copy of the string is stored instead unless the original string is already frozen.
Comparison¶ ↑
The comparison operators <, >, <=, and >= are implemented as shorthand for the {proper_,}{subset?,superset?} methods. However, the <=> operator is intentionally left out because not every pair of sets is comparable ({x, y} vs. {x, z} for example).
Example¶ ↑
require 'set' s1 = Set[1, 2] #=> #<Set: {1, 2}> s2 = [1, 2].to_set #=> #<Set: {1, 2}> s1 == s2 #=> true s1.add("foo") #=> #<Set: {1, 2, "foo"}> s1.merge([2, 6]) #=> #<Set: {1, 2, "foo", 6}> s1.subset?(s2) #=> false s2.subset?(s1) #=> true
Contact¶ ↑
- Akinori MUSHA <knu@iDaemons.org> (current maintainer)
Public Class Methods
Creates a new set containing the given objects.
Set[1, 2] # => #<Set: {1, 2}> Set[1, 2, 1] # => #<Set: {1, 2}> Set[1, 'c', :s] # => #<Set: {1, "c", :s}>
# File set.rb, line 78 def self.[](*ary) new(ary) end
Creates a new set containing the elements of the given enumerable object.
If a block is given, the elements of enum are preprocessed by the given block.
Set.new([1, 2]) #=> #<Set: {1, 2}> Set.new([1, 2, 1]) #=> #<Set: {1, 2}> Set.new([1, 'c', :s]) #=> #<Set: {1, "c", :s}> Set.new(1..5) #=> #<Set: {1, 2, 3, 4, 5}> Set.new([1, 2, 3]) { |x| x * x } #=> #<Set: {1, 4, 9}>
# File set.rb, line 93 def initialize(enum = nil, &block) # :yields: o @hash ||= Hash.new(false) enum.nil? and return if block do_with_enum(enum) { |o| add(block[o]) } else merge(enum) end end
Public Instance Methods
Returns a new set containing elements common to the set and the given enumerable object.
Set[1, 3, 5] & Set[3, 2, 1] #=> #<Set: {3, 1}> Set['a', 'b', 'z'] & ['a', 'b', 'c'] #=> #<Set: {"a", "b"}>
# File set.rb, line 465 def &(enum) n = self.class.new if enum.is_a?(Set) if enum.size > size each { |o| n.add(o) if enum.include?(o) } else enum.each { |o| n.add(o) if include?(o) } end else do_with_enum(enum) { |o| n.add(o) if include?(o) } end n end
Returns a new set built by duplicating the set, removing every element that appears in the given enumerable object.
Set[1, 3, 5] - Set[1, 5] #=> #<Set: {3}> Set['a', 'b', 'z'] - ['a', 'c'] #=> #<Set: {"b", "z"}>
# File set.rb, line 455 def -(enum) dup.subtract(enum) end
Returns true if two sets are equal. The equality of each couple of elements is defined according to Object#eql?.
Set[1, 2] == Set[2, 1] #=> true Set[1, 3, 5] == Set[1, 5] #=> false Set['a', 'b', 'c'] == Set['a', 'c', 'b'] #=> true Set['a', 'b', 'c'] == ['a', 'c', 'b'] #=> false
# File set.rb, line 499 def ==(other) if self.equal?(other) true elsif other.instance_of?(self.class) @hash == other.instance_variable_get(:@hash) elsif other.is_a?(Set) && self.size == other.size other.all? { |o| @hash.include?(o) } else false end end
Returns true if the given object is a member of the set, and false otherwise.
Used in case statements:
require 'set' case :apple when Set[:potato, :carrot] "vegetable" when Set[:apple, :banana] "fruit" end # => "fruit"
Or by itself:
Set[1, 2, 3] === 2 #=> true Set[1, 2, 3] === 4 #=> false
Returns a new set containing elements exclusive between the set and the given enumerable object. (set ^ enum) is equivalent to ((set | enum) - (set & enum)).
Set[1, 2] ^ Set[2, 3] #=> #<Set: {3, 1}> Set[1, 'b', 'c'] ^ ['b', 'd'] #=> #<Set: {"d", 1, "c"}>
# File set.rb, line 486 def ^(enum) n = Set.new(enum) each { |o| n.add(o) unless n.delete?(o) } n end
Adds the given object to the set and returns self. Use merge to add many elements at once.
Set[1, 2].add(3) #=> #<Set: {1, 2, 3}> Set[1, 2].add([3, 4]) #=> #<Set: {1, 2, [3, 4]}> Set[1, 2].add(2) #=> #<Set: {1, 2}>
# File set.rb, line 338 def add(o) @hash[o] = true self end
Adds the given object to the set and returns self. If the object is already in the set, returns nil.
Set[1, 2].add?(3) #=> #<Set: {1, 2, 3}> Set[1, 2].add?([3, 4]) #=> #<Set: {1, 2, [3, 4]}> Set[1, 2].add?(2) #=> nil
# File set.rb, line 350 def add?(o) add(o) unless include?(o) end
Classifies the set by the return value of the given block and returns a hash of {value => set of elements} pairs. The block is called once for each element of the set, passing the element as parameter.
require 'set' files = Set.new(Dir.glob("*.rb")) hash = files.classify { |f| File.mtime(f).year } hash #=> {2000=>#<Set: {"a.rb", "b.rb"}>, # 2001=>#<Set: {"c.rb", "d.rb", "e.rb"}>, # 2002=>#<Set: {"f.rb"}>}
Returns an enumerator if no block is given.
# File set.rb, line 568 def classify # :yields: o block_given? or return enum_for(__method__) { size } h = {} each { |i| (h[yield(i)] ||= self.class.new).add(i) } h end
Removes all elements and returns self.
set = Set[1, 'c', :s] #=> #<Set: {1, "c", :s}> set.clear #=> #<Set: {}> set #=> #<Set: {}>
# File set.rb, line 166 def clear @hash.clear self end
Replaces the elements with ones returned by collect(). Returns an enumerator if no block is given.
# File set.rb, line 391 def collect! block_given? or return enum_for(__method__) { size } set = self.class.new each { |o| set << yield(o) } replace(set) end
Makes the set compare its elements by their identity and returns self. This method may not be supported by all subclasses of Set.
# File set.rb, line 107 def compare_by_identity if @hash.respond_to?(:compare_by_identity) @hash.compare_by_identity self else raise NotImplementedError, "#{self.class.name}\##{__method__} is not implemented" end end
Returns true if the set will compare its elements by their identity. Also see #compare_by_identity.
# File set.rb, line 118 def compare_by_identity? @hash.respond_to?(:compare_by_identity?) && @hash.compare_by_identity? end
Deletes the given object from the set and returns self. Use subtract to delete many items at once.
# File set.rb, line 356 def delete(o) @hash.delete(o) self end
Deletes the given object from the set and returns self. If the object is not in the set, returns nil.
# File set.rb, line 363 def delete?(o) delete(o) if include?(o) end
Deletes every element of the set for which block evaluates to true, and returns self. Returns an enumerator if no block is given.
# File set.rb, line 370 def delete_if block_given? or return enum_for(__method__) { size } # @hash.delete_if should be faster, but using it breaks the order # of enumeration in subclasses. select { |o| yield o }.each { |o| @hash.delete(o) } self end
Returns true if the set and the given set have no element in common. This method is the opposite of intersect?.
Set[1, 2, 3].disjoint? Set[3, 4] #=> false Set[1, 2, 3].disjoint? Set[4, 5] #=> true
# File set.rb, line 319 def disjoint?(set) !intersect?(set) end
Divides the set into a set of subsets according to the commonality defined by the given block.
If the arity of the block is 2, elements o1 and o2 are in common if block.call(o1, o2) is true. Otherwise, elements o1 and o2 are in common if block.call(o1) == block.call(o2).
require 'set' numbers = Set[1, 3, 4, 6, 9, 10, 11] set = numbers.divide { |i,j| (i - j).abs == 1 } set #=> #<Set: {#<Set: {1}>, # #<Set: {11, 9, 10}>, # #<Set: {3, 4}>, # #<Set: {6}>}>
Returns an enumerator if no block is given.
# File set.rb, line 596 def divide(&func) func or return enum_for(__method__) { size } if func.arity == 2 require 'tsort' class << dig = {} # :nodoc: include TSort alias tsort_each_node each_key def tsort_each_child(node, &block) fetch(node).each(&block) end end each { |u| dig[u] = a = [] each{ |v| func.call(u, v) and a << v } } set = Set.new() dig.each_strongly_connected_component { |css| set.add(self.class.new(css)) } set else Set.new(classify(&func).values) end 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 set.rb, line 326 def each(&block) block or return enum_for(__method__) { size } @hash.each_key(&block) self end
Returns true if the set contains no elements.
# File set.rb, line 157 def empty? @hash.empty? end
Returns a new set that is a copy of the set, flattening each containing set recursively.
# File set.rb, line 227 def flatten self.class.new.flatten_merge(self) end
Equivalent to #flatten, but replaces the receiver with the result in place. Returns nil if no modifications were made.
# File set.rb, line 233 def flatten! replace(flatten()) if any? { |e| e.is_a?(Set) } end
Returns true if the set contains the given object.
Note that include? and member? do not test member equality using == as do other Enumerables.
See also Enumerable#include?
# File set.rb, line 243 def include?(o) @hash[o] end
Clone internal hash.
# File set.rb, line 140 def initialize_clone(orig, freeze: true) super @hash = orig.instance_variable_get(:@hash).clone(freeze: freeze) end
Dup internal hash.
# File set.rb, line 134 def initialize_dup(orig) super @hash = orig.instance_variable_get(:@hash).dup end
Returns a string containing a human-readable representation of the set (“#<Set: {element1, element2, …}>”).
# File set.rb, line 630 def inspect ids = (Thread.current[InspectKey] ||= []) if ids.include?(object_id) return sprintf('#<%s: {...}>', self.class.name) end ids << object_id begin return sprintf('#<%s: {%s}>', self.class, to_a.inspect[1..-2]) ensure ids.pop end end
Returns true if the set and the given set have at least one element in common.
Set[1, 2, 3].intersect? Set[4, 5] #=> false Set[1, 2, 3].intersect? Set[3, 4] #=> true
# File set.rb, line 305 def intersect?(set) set.is_a?(Set) or raise ArgumentError, "value must be a set" if size < set.size any? { |o| set.include?(o) } else set.any? { |o| include?(o) } end end
Deletes every element of the set for which block evaluates to false, and returns self. Returns an enumerator if no block is given.
# File set.rb, line 381 def keep_if block_given? or return enum_for(__method__) { size } # @hash.keep_if should be faster, but using it breaks the order of # enumeration in subclasses. reject { |o| yield o }.each { |o| @hash.delete(o) } self end
Merges the elements of the given enumerable object to the set and returns self.
# File set.rb, line 422 def merge(enum) if enum.instance_of?(self.class) @hash.update(enum.instance_variable_get(:@hash)) else do_with_enum(enum) { |o| add(o) } end self end
Returns true if the set is a proper subset of the given set.
# File set.rb, line 288 def proper_subset?(set) case when set.instance_of?(self.class) && @hash.respond_to?(:<) @hash < set.instance_variable_get(:@hash) when set.is_a?(Set) size < set.size && all? { |o| set.include?(o) } else raise ArgumentError, "value must be a set" end end
Returns true if the set is a proper superset of the given set.
# File set.rb, line 262 def proper_superset?(set) case when set.instance_of?(self.class) && @hash.respond_to?(:>) @hash > set.instance_variable_get(:@hash) when set.is_a?(Set) size > set.size && set.all? { |o| include?(o) } else raise ArgumentError, "value must be a set" end end
Equivalent to #delete_if, but returns nil if no changes were made. Returns an enumerator if no block is given.
# File set.rb, line 401 def reject!(&block) block or return enum_for(__method__) { size } n = size delete_if(&block) self if size != n end
Replaces the contents of the set with the contents of the given enumerable object and returns self.
set = Set[1, 'c', :s] #=> #<Set: {1, "c", :s}> set.replace([1, 2]) #=> #<Set: {1, 2}> set #=> #<Set: {1, 2}>
# File set.rb, line 177 def replace(enum) if enum.instance_of?(self.class) @hash.replace(enum.instance_variable_get(:@hash)) self else do_with_enum(enum) # make sure enum is enumerable before calling clear clear merge(enum) end end
Resets the internal state after modification to existing elements and returns self.
Elements will be reindexed and deduplicated.
# File set.rb, line 524 def reset if @hash.respond_to?(:rehash) @hash.rehash # This should perform frozenness check. else raise FrozenError, "can't modify frozen #{self.class.name}" if frozen? end self end
Equivalent to #keep_if, but returns nil if no changes were made. Returns an enumerator if no block is given.
# File set.rb, line 410 def select!(&block) block or return enum_for(__method__) { size } n = size keep_if(&block) self if size != n end
Returns the number of elements.
# File set.rb, line 151 def size @hash.size end
Returns true if the set is a subset of the given set.
# File set.rb, line 275 def subset?(set) case when set.instance_of?(self.class) && @hash.respond_to?(:<=) @hash <= set.instance_variable_get(:@hash) when set.is_a?(Set) size <= set.size && all? { |o| set.include?(o) } else raise ArgumentError, "value must be a set" end end
Deletes every element that appears in the given enumerable object and returns self.
# File set.rb, line 434 def subtract(enum) do_with_enum(enum) { |o| delete(o) } self end
Returns true if the set is a superset of the given set.
# File set.rb, line 249 def superset?(set) case when set.instance_of?(self.class) && @hash.respond_to?(:>=) @hash >= set.instance_variable_get(:@hash) when set.is_a?(Set) size >= set.size && set.all? { |o| include?(o) } else raise ArgumentError, "value must be a set" end end
Converts the set to an array. The order of elements is uncertain.
Set[1, 2].to_a #=> [1, 2] Set[1, 'c', :s].to_a #=> [1, "c", :s]
# File set.rb, line 192 def to_a @hash.keys end
Returns self if no arguments are given. Otherwise, converts the set to another with klass.new(self, *args, &block).
In subclasses, returns klass.new(self, *args, &block) unless overridden.
# File set.rb, line 201 def to_set(klass = Set, *args, &block) return self if instance_of?(Set) && klass == Set && block.nil? && args.empty? klass.new(self, *args, &block) end