class 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.
The equality of each couple of elements is determined according to Object#eql? and Object#hash, since Set
uses Hash as storage.
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.
Example¶ ↑
require 'set' s1 = Set.new [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: {6, 1, 2, "foo"}> 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.
# File lib/rubysl/set/set.rb, line 58 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.
# File lib/rubysl/set/set.rb, line 67 def initialize(enum = nil, &block) # :yields: o @hash ||= Hash.new 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.
# File lib/rubysl/set/set.rb, line 340 def &(enum) n = self.class.new do_with_enum(enum) { |o| n.add(o) if include?(o) } n end
Returns a new set built by duplicating the set, removing every element that appears in the given enumerable object.
# File lib/rubysl/set/set.rb, line 333 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?.
# File lib/rubysl/set/set.rb, line 358 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 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/rubysl/set/set.rb, line 350 def ^(enum) n = Set.new(enum) each { |o| if n.include?(o) then n.delete(o) else n.add(o) end } n end
Adds the given object to the set and returns self. Use merge
to add many elements at once.
# File lib/rubysl/set/set.rb, line 228 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.
# File lib/rubysl/set/set.rb, line 236 def add?(o) if include?(o) nil else add(o) end 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.
e.g.:
require 'set' files = Set.new(Dir.glob("*.rb")) hash = files.classify { |f| File.mtime(f).year } p hash # => {2000=>#<Set: {"a.rb", "b.rb"}>, # 2001=>#<Set: {"c.rb", "d.rb", "e.rb"}>, # 2002=>#<Set: {"f.rb"}>}
# File lib/rubysl/set/set.rb, line 392 def classify # :yields: o block_given? or return enum_for(__method__) h = {} each { |i| x = yield(i) (h[x] ||= self.class.new).add(i) } h end
Removes all elements and returns self.
# File lib/rubysl/set/set.rb, line 125 def clear @hash.clear self end
Replaces the elements with ones returned by collect().
# File lib/rubysl/set/set.rb, line 278 def collect! block_given? or return enum_for(__method__) set = self.class.new each { |o| set << yield(o) } replace(set) end
Deletes the given object from the set and returns self. Use subtract
to delete many items at once.
# File lib/rubysl/set/set.rb, line 246 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 lib/rubysl/set/set.rb, line 253 def delete?(o) if include?(o) delete(o) else nil end end
Deletes every element of the set for which block evaluates to true, and returns self.
# File lib/rubysl/set/set.rb, line 263 def delete_if block_given? or return enum_for(__method__) to_a.each { |o| @hash.delete(o) if yield(o) } self 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).
e.g.:
require 'set' numbers = Set[1, 3, 4, 6, 9, 10, 11] set = numbers.divide { |i,j| (i - j).abs == 1 } p set # => #<Set: {#<Set: {1}>, # #<Set: {11, 9, 10}>, # #<Set: {3, 4}>, # #<Set: {6}>}>
# File lib/rubysl/set/set.rb, line 421 def divide(&func) func or return enum_for(__method__) 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 lib/rubysl/set/set.rb, line 220 def each block_given? or return enum_for(__method__) @hash.each_key { |o| yield(o) } self end
Returns true if the set contains no elements.
# File lib/rubysl/set/set.rb, line 120 def empty? @hash.empty? end
Returns a new set that is a copy of the set, flattening each containing set recursively.
# File lib/rubysl/set/set.rb, line 169 def flatten self.class.new.flatten_merge(self) end
Equivalent to Set#flatten
, but replaces the receiver with the result in place. Returns nil if no modifications were made.
# File lib/rubysl/set/set.rb, line 175 def flatten! if detect { |e| e.is_a?(Set) } replace(flatten()) else nil end end
Returns true if the set contains the given object.
# File lib/rubysl/set/set.rb, line 184 def include?(o) @hash.include?(o) end
Copy internal hash.
# File lib/rubysl/set/set.rb, line 91 def initialize_copy(orig) @hash = orig.instance_eval{@hash}.dup end
Returns a string containing a human-readable representation of the set. (“#<Set: {element1, element2, …}>”)
# File lib/rubysl/set/set.rb, line 455 def inspect ids = (Thread.current[InspectKey] ||= []) if ids.include?(object_id) return sprintf('#<%s: {...}>', self.class.name) end begin ids << object_id return sprintf('#<%s: {%s}>', self.class, to_a.inspect[1..-2]) ensure ids.pop end end
Deletes every element of the set for which block evaluates to false, and returns self.
# File lib/rubysl/set/set.rb, line 271 def keep_if block_given? or return enum_for(__method__) to_a.each { |o| @hash.delete(o) unless yield(o) } self end
Merges the elements of the given enumerable object to the set and returns self.
# File lib/rubysl/set/set.rb, line 306 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 lib/rubysl/set/set.rb, line 211 def proper_subset?(set) set.is_a?(Set) or raise ArgumentError, "value must be a set" return false if set.size <= size all? { |o| set.include?(o) } end
Returns true if the set is a proper superset of the given set.
# File lib/rubysl/set/set.rb, line 197 def proper_superset?(set) set.is_a?(Set) or raise ArgumentError, "value must be a set" return false if size <= set.size set.all? { |o| include?(o) } end
Equivalent to Set#delete_if
, but returns nil if no changes were made.
# File lib/rubysl/set/set.rb, line 288 def reject! block_given? or return enum_for(__method__) n = size delete_if { |o| yield(o) } size == n ? nil : self end
Replaces the contents of the set with the contents of the given enumerable object and returns self.
# File lib/rubysl/set/set.rb, line 132 def replace(enum) if enum.class == self.class @hash.replace(enum.instance_eval { @hash }) else clear merge(enum) end self end
Equivalent to Set#keep_if
, but returns nil if no changes were made.
# File lib/rubysl/set/set.rb, line 297 def select! block_given? or return enum_for(__method__) n = size keep_if { |o| yield(o) } size == n ? nil : self end
Returns the number of elements.
# File lib/rubysl/set/set.rb, line 114 def size @hash.size end
Returns true if the set is a subset of the given set.
# File lib/rubysl/set/set.rb, line 204 def subset?(set) set.is_a?(Set) or raise ArgumentError, "value must be a set" return false if set.size < size all? { |o| set.include?(o) } end
Deletes every element that appears in the given enumerable object and returns self.
# File lib/rubysl/set/set.rb, line 318 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 lib/rubysl/set/set.rb, line 190 def superset?(set) set.is_a?(Set) or raise ArgumentError, "value must be a set" return false if size < set.size set.all? { |o| include?(o) } end
Converts the set to an array. The order of elements is uncertain.
# File lib/rubysl/set/set.rb, line 144 def to_a @hash.keys end
Protected Instance Methods
# File lib/rubysl/set/set.rb, line 148 def flatten_merge(set, seen = Set.new) set.each { |e| if e.is_a?(Set) if seen.include?(e_id = e.object_id) raise ArgumentError, "tried to flatten recursive Set" end seen.add(e_id) flatten_merge(e, seen) seen.delete(e_id) else add(e) end } self end
Private Instance Methods
# File lib/rubysl/set/set.rb, line 79 def do_with_enum(enum, &block) if enum.respond_to?(:each_entry) enum.each_entry(&block) elsif enum.respond_to?(:each) enum.each(&block) else raise ArgumentError, "value must be enumerable" end end