зеркало из https://github.com/github/ruby.git
768 строки
19 KiB
Ruby
768 строки
19 KiB
Ruby
#--
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# set.rb - defines the Set class
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#++
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# Copyright (c) 2002-2013 Akinori MUSHA <knu@iDaemons.org>
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#
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# Documentation by Akinori MUSHA and Gavin Sinclair.
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#
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# All rights reserved. You can redistribute and/or modify it under the same
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# terms as Ruby.
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#
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# $Id$
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#
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# == Overview
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#
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# This library provides the Set class, which deals with a collection
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# of unordered values with no duplicates. It is a hybrid of Array's
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# intuitive inter-operation facilities and Hash's fast lookup. If you
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# need to keep values sorted in some order, use the SortedSet class.
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#
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# The method +to_set+ is added to Enumerable for convenience.
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#
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# See the Set and SortedSet documentation for examples of usage.
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#
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# Set implements a collection of unordered values with no duplicates.
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# This is a hybrid of Array's intuitive inter-operation facilities and
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# Hash's fast lookup.
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#
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# Set is easy to use with Enumerable objects (implementing +each+).
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# Most of the initializer methods and binary operators accept generic
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# Enumerable objects besides sets and arrays. An Enumerable object
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# can be converted to Set using the +to_set+ method.
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#
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# Set uses Hash as storage, so you must note the following points:
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#
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# * Equality of elements is determined according to Object#eql? and
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# Object#hash.
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# * Set assumes that the identity of each element does not change
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# while it is stored. Modifying an element of a set will render the
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# set to an unreliable state.
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# * When a string is to be stored, a frozen copy of the string is
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# stored instead unless the original string is already frozen.
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#
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# == Comparison
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#
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# The comparison operators <, >, <= and >= are implemented as
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# shorthand for the {proper_,}{subset?,superset?} methods. However,
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# the <=> operator is intentionally left out because not every pair of
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# sets is comparable. ({x,y} vs. {x,z} for example)
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#
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# == Example
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#
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# require 'set'
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# s1 = Set.new [1, 2] # -> #<Set: {1, 2}>
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# s2 = [1, 2].to_set # -> #<Set: {1, 2}>
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# s1 == s2 # -> true
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# s1.add("foo") # -> #<Set: {1, 2, "foo"}>
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# s1.merge([2, 6]) # -> #<Set: {1, 2, "foo", 6}>
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# s1.subset? s2 # -> false
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# s2.subset? s1 # -> true
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#
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# == Contact
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#
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# - Akinori MUSHA <knu@iDaemons.org> (current maintainer)
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#
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class Set
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include Enumerable
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# Creates a new set containing the given objects.
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def self.[](*ary)
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new(ary)
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end
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# Creates a new set containing the elements of the given enumerable
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# object.
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#
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# If a block is given, the elements of enum are preprocessed by the
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# given block.
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def initialize(enum = nil, &block) # :yields: o
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@hash ||= Hash.new
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enum.nil? and return
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if block
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do_with_enum(enum) { |o| add(block[o]) }
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else
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merge(enum)
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end
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end
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def do_with_enum(enum, &block) # :nodoc:
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if enum.respond_to?(:each_entry)
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enum.each_entry(&block)
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elsif enum.respond_to?(:each)
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enum.each(&block)
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else
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raise ArgumentError, "value must be enumerable"
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end
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end
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private :do_with_enum
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# Copy internal hash.
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def initialize_copy(orig)
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@hash = orig.instance_variable_get(:@hash).dup
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end
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def freeze # :nodoc:
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@hash.freeze
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super
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end
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def taint # :nodoc:
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@hash.taint
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super
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end
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def untaint # :nodoc:
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@hash.untaint
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super
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end
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# Returns the number of elements.
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def size
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@hash.size
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end
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alias length size
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# Returns true if the set contains no elements.
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def empty?
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@hash.empty?
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end
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# Removes all elements and returns self.
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def clear
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@hash.clear
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self
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end
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# Replaces the contents of the set with the contents of the given
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# enumerable object and returns self.
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def replace(enum)
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if enum.instance_of?(self.class)
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@hash.replace(enum.instance_variable_get(:@hash))
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else
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clear
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merge(enum)
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end
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self
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end
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# Converts the set to an array. The order of elements is uncertain.
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def to_a
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@hash.keys
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end
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# Returns self if no arguments are given. Otherwise, converts the
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# set to another with klass.new(self, *args, &block).
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#
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# In subclasses, returns klass.new(self, *args, &block) unless
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# overridden.
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def to_set(klass = Set, *args, &block)
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return self if instance_of?(Set) && klass == Set && block.nil? && args.empty?
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klass.new(self, *args, &block)
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end
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def flatten_merge(set, seen = Set.new) # :nodoc:
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set.each { |e|
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if e.is_a?(Set)
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if seen.include?(e_id = e.object_id)
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raise ArgumentError, "tried to flatten recursive Set"
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end
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seen.add(e_id)
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flatten_merge(e, seen)
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seen.delete(e_id)
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else
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add(e)
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end
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}
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self
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end
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protected :flatten_merge
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# Returns a new set that is a copy of the set, flattening each
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# containing set recursively.
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def flatten
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self.class.new.flatten_merge(self)
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end
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# Equivalent to Set#flatten, but replaces the receiver with the
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# result in place. Returns nil if no modifications were made.
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def flatten!
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if detect { |e| e.is_a?(Set) }
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replace(flatten())
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else
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nil
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end
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end
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# Returns true if the set contains the given object.
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def include?(o)
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@hash.include?(o)
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end
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alias member? include?
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# Returns true if the set is a superset of the given set.
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def superset?(set)
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set.is_a?(Set) or raise ArgumentError, "value must be a set"
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return false if size < set.size
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set.all? { |o| include?(o) }
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end
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alias >= superset?
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# Returns true if the set is a proper superset of the given set.
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def proper_superset?(set)
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set.is_a?(Set) or raise ArgumentError, "value must be a set"
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return false if size <= set.size
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set.all? { |o| include?(o) }
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end
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alias > proper_superset?
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# Returns true if the set is a subset of the given set.
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def subset?(set)
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set.is_a?(Set) or raise ArgumentError, "value must be a set"
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return false if set.size < size
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all? { |o| set.include?(o) }
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end
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alias <= subset?
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# Returns true if the set is a proper subset of the given set.
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def proper_subset?(set)
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set.is_a?(Set) or raise ArgumentError, "value must be a set"
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return false if set.size <= size
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all? { |o| set.include?(o) }
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end
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alias < proper_subset?
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# Returns true if the set and the given set have at least one
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# element in common.
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def intersect?(set)
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set.is_a?(Set) or raise ArgumentError, "value must be a set"
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if size < set.size
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any? { |o| set.include?(o) }
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else
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set.any? { |o| include?(o) }
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end
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end
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# Returns true if the set and the given set have no element in
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# common. This method is the opposite of +intersect?+.
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def disjoint?(set)
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!intersect?(set)
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end
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# Calls the given block once for each element in the set, passing
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# the element as parameter. Returns an enumerator if no block is
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# given.
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def each(&block)
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block or return enum_for(__method__)
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@hash.each_key(&block)
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self
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end
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# Adds the given object to the set and returns self. Use +merge+ to
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# add many elements at once.
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def add(o)
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@hash[o] = true
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self
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end
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alias << add
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# Adds the given object to the set and returns self. If the
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# object is already in the set, returns nil.
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def add?(o)
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if include?(o)
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nil
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else
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add(o)
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end
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end
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# Deletes the given object from the set and returns self. Use +subtract+ to
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# delete many items at once.
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def delete(o)
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@hash.delete(o)
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self
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end
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# Deletes the given object from the set and returns self. If the
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# object is not in the set, returns nil.
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def delete?(o)
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if include?(o)
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delete(o)
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else
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nil
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end
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end
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# Deletes every element of the set for which block evaluates to
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# true, and returns self.
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def delete_if
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block_given? or return enum_for(__method__)
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# @hash.delete_if should be faster, but using it breaks the order
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# of enumeration in subclasses.
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select { |o| yield o }.each { |o| @hash.delete(o) }
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self
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end
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# Deletes every element of the set for which block evaluates to
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# false, and returns self.
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def keep_if
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block_given? or return enum_for(__method__)
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# @hash.keep_if should be faster, but using it breaks the order of
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# enumeration in subclasses.
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reject { |o| yield o }.each { |o| @hash.delete(o) }
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self
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end
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# Replaces the elements with ones returned by collect().
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def collect!
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block_given? or return enum_for(__method__)
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set = self.class.new
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each { |o| set << yield(o) }
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replace(set)
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end
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alias map! collect!
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# Equivalent to Set#delete_if, but returns nil if no changes were
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# made.
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def reject!(&block)
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block or return enum_for(__method__)
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n = size
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delete_if(&block)
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size == n ? nil : self
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end
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# Equivalent to Set#keep_if, but returns nil if no changes were
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# made.
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def select!(&block)
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block or return enum_for(__method__)
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n = size
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keep_if(&block)
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size == n ? nil : self
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end
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# Merges the elements of the given enumerable object to the set and
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# returns self.
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def merge(enum)
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if enum.instance_of?(self.class)
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@hash.update(enum.instance_variable_get(:@hash))
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else
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do_with_enum(enum) { |o| add(o) }
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end
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self
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end
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# Deletes every element that appears in the given enumerable object
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# and returns self.
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def subtract(enum)
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do_with_enum(enum) { |o| delete(o) }
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self
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end
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# Returns a new set built by merging the set and the elements of the
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# given enumerable object.
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def |(enum)
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dup.merge(enum)
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end
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alias + | ##
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alias union | ##
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# Returns a new set built by duplicating the set, removing every
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# element that appears in the given enumerable object.
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def -(enum)
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dup.subtract(enum)
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end
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alias difference - ##
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# Returns a new set containing elements common to the set and the
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# given enumerable object.
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def &(enum)
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n = self.class.new
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do_with_enum(enum) { |o| n.add(o) if include?(o) }
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n
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end
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alias intersection & ##
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# Returns a new set containing elements exclusive between the set
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# and the given enumerable object. (set ^ enum) is equivalent to
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# ((set | enum) - (set & enum)).
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def ^(enum)
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n = Set.new(enum)
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each { |o| if n.include?(o) then n.delete(o) else n.add(o) end }
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n
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end
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# Returns true if two sets are equal. The equality of each couple
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# of elements is defined according to Object#eql?.
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def ==(other)
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if self.equal?(other)
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true
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elsif other.instance_of?(self.class)
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@hash == other.instance_variable_get(:@hash)
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elsif other.is_a?(Set) && self.size == other.size
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other.all? { |o| @hash.include?(o) }
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else
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false
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end
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end
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def hash # :nodoc:
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@hash.hash
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end
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def eql?(o) # :nodoc:
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return false unless o.is_a?(Set)
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@hash.eql?(o.instance_variable_get(:@hash))
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end
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# Classifies the set by the return value of the given block and
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# returns a hash of {value => set of elements} pairs. The block is
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# called once for each element of the set, passing the element as
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# parameter.
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#
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# e.g.:
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#
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# require 'set'
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# files = Set.new(Dir.glob("*.rb"))
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# hash = files.classify { |f| File.mtime(f).year }
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# p hash # => {2000=>#<Set: {"a.rb", "b.rb"}>,
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# # 2001=>#<Set: {"c.rb", "d.rb", "e.rb"}>,
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# # 2002=>#<Set: {"f.rb"}>}
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def classify # :yields: o
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block_given? or return enum_for(__method__)
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h = {}
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each { |i|
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x = yield(i)
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(h[x] ||= self.class.new).add(i)
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}
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h
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end
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# Divides the set into a set of subsets according to the commonality
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# defined by the given block.
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#
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# If the arity of the block is 2, elements o1 and o2 are in common
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# if block.call(o1, o2) is true. Otherwise, elements o1 and o2 are
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# in common if block.call(o1) == block.call(o2).
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#
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# e.g.:
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#
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# require 'set'
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# numbers = Set[1, 3, 4, 6, 9, 10, 11]
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# set = numbers.divide { |i,j| (i - j).abs == 1 }
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# p set # => #<Set: {#<Set: {1}>,
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# # #<Set: {11, 9, 10}>,
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# # #<Set: {3, 4}>,
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# # #<Set: {6}>}>
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def divide(&func)
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func or return enum_for(__method__)
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if func.arity == 2
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require 'tsort'
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class << dig = {} # :nodoc:
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include TSort
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alias tsort_each_node each_key
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def tsort_each_child(node, &block)
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fetch(node).each(&block)
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end
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end
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each { |u|
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dig[u] = a = []
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each{ |v| func.call(u, v) and a << v }
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}
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set = Set.new()
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dig.each_strongly_connected_component { |css|
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set.add(self.class.new(css))
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}
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set
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else
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Set.new(classify(&func).values)
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end
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end
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InspectKey = :__inspect_key__ # :nodoc:
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# Returns a string containing a human-readable representation of the
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# set. ("#<Set: {element1, element2, ...}>")
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def inspect
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ids = (Thread.current[InspectKey] ||= [])
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if ids.include?(object_id)
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return sprintf('#<%s: {...}>', self.class.name)
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end
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begin
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ids << object_id
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return sprintf('#<%s: {%s}>', self.class, to_a.inspect[1..-2])
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ensure
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ids.pop
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end
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end
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def pretty_print(pp) # :nodoc:
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pp.text sprintf('#<%s: {', self.class.name)
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pp.nest(1) {
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pp.seplist(self) { |o|
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pp.pp o
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}
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}
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pp.text "}>"
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end
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def pretty_print_cycle(pp) # :nodoc:
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pp.text sprintf('#<%s: {%s}>', self.class.name, empty? ? '' : '...')
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end
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end
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#
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# SortedSet implements a Set that guarantees that it's element are
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# yielded in sorted order (according to the return values of their
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# #<=> methods) when iterating over them.
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#
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# All elements that are added to a SortedSet must respond to the <=>
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# method for comparison.
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#
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# Also, all elements must be <em>mutually comparable</em>: <tt>el1 <=>
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# el2</tt> must not return <tt>nil</tt> for any elements <tt>el1</tt>
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# and <tt>el2</tt>, else an ArgumentError will be raised when
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# iterating over the SortedSet.
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#
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# == Example
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#
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# require "set"
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#
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# set = SortedSet.new([2, 1, 5, 6, 4, 5, 3, 3, 3])
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# ary = []
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#
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# set.each do |obj|
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# ary << obj
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# end
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#
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# p ary # => [1, 2, 3, 4, 5, 6]
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|
#
|
|
# set2 = SortedSet.new([1, 2, "3"])
|
|
# set2.each { |obj| } # => raises ArgumentError: comparison of Fixnum with String failed
|
|
#
|
|
class SortedSet < Set
|
|
@@setup = false
|
|
|
|
class << self
|
|
def [](*ary) # :nodoc:
|
|
new(ary)
|
|
end
|
|
|
|
def setup # :nodoc:
|
|
@@setup and return
|
|
|
|
module_eval {
|
|
# a hack to shut up warning
|
|
alias old_init initialize
|
|
}
|
|
begin
|
|
require 'rbtree'
|
|
|
|
module_eval <<-END, __FILE__, __LINE__+1
|
|
def initialize(*args)
|
|
@hash = RBTree.new
|
|
super
|
|
end
|
|
|
|
def add(o)
|
|
o.respond_to?(:<=>) or raise ArgumentError, "value must respond to <=>"
|
|
super
|
|
end
|
|
alias << add
|
|
END
|
|
rescue LoadError
|
|
module_eval <<-END, __FILE__, __LINE__+1
|
|
def initialize(*args)
|
|
@keys = nil
|
|
super
|
|
end
|
|
|
|
def clear
|
|
@keys = nil
|
|
super
|
|
end
|
|
|
|
def replace(enum)
|
|
@keys = nil
|
|
super
|
|
end
|
|
|
|
def add(o)
|
|
o.respond_to?(:<=>) or raise ArgumentError, "value must respond to <=>"
|
|
@keys = nil
|
|
super
|
|
end
|
|
alias << add
|
|
|
|
def delete(o)
|
|
@keys = nil
|
|
@hash.delete(o)
|
|
self
|
|
end
|
|
|
|
def delete_if
|
|
block_given? or return enum_for(__method__)
|
|
n = @hash.size
|
|
super
|
|
@keys = nil if @hash.size != n
|
|
self
|
|
end
|
|
|
|
def keep_if
|
|
block_given? or return enum_for(__method__)
|
|
n = @hash.size
|
|
super
|
|
@keys = nil if @hash.size != n
|
|
self
|
|
end
|
|
|
|
def merge(enum)
|
|
@keys = nil
|
|
super
|
|
end
|
|
|
|
def each(&block)
|
|
block or return enum_for(__method__)
|
|
to_a.each(&block)
|
|
self
|
|
end
|
|
|
|
def to_a
|
|
(@keys = @hash.keys).sort! unless @keys
|
|
@keys
|
|
end
|
|
END
|
|
end
|
|
module_eval {
|
|
# a hack to shut up warning
|
|
remove_method :old_init
|
|
}
|
|
|
|
@@setup = true
|
|
end
|
|
end
|
|
|
|
def initialize(*args, &block) # :nodoc:
|
|
SortedSet.setup
|
|
initialize(*args, &block)
|
|
end
|
|
end
|
|
|
|
module Enumerable
|
|
# Makes a set from the enumerable object with given arguments.
|
|
# Needs to +require "set"+ to use this method.
|
|
def to_set(klass = Set, *args, &block)
|
|
klass.new(self, *args, &block)
|
|
end
|
|
end
|
|
|
|
# =begin
|
|
# == RestricedSet class
|
|
# RestricedSet implements a set with restrictions defined by a given
|
|
# block.
|
|
#
|
|
# === Super class
|
|
# Set
|
|
#
|
|
# === Class Methods
|
|
# --- RestricedSet::new(enum = nil) { |o| ... }
|
|
# --- RestricedSet::new(enum = nil) { |rset, o| ... }
|
|
# Creates a new restricted set containing the elements of the given
|
|
# enumerable object. Restrictions are defined by the given block.
|
|
#
|
|
# If the block's arity is 2, it is called with the RestrictedSet
|
|
# itself and an object to see if the object is allowed to be put in
|
|
# the set.
|
|
#
|
|
# Otherwise, the block is called with an object to see if the object
|
|
# is allowed to be put in the set.
|
|
#
|
|
# === Instance Methods
|
|
# --- restriction_proc
|
|
# Returns the restriction procedure of the set.
|
|
#
|
|
# =end
|
|
#
|
|
# class RestricedSet < Set
|
|
# def initialize(*args, &block)
|
|
# @proc = block or raise ArgumentError, "missing a block"
|
|
#
|
|
# if @proc.arity == 2
|
|
# instance_eval %{
|
|
# def add(o)
|
|
# @hash[o] = true if @proc.call(self, o)
|
|
# self
|
|
# end
|
|
# alias << add
|
|
#
|
|
# def add?(o)
|
|
# if include?(o) || !@proc.call(self, o)
|
|
# nil
|
|
# else
|
|
# @hash[o] = true
|
|
# self
|
|
# end
|
|
# end
|
|
#
|
|
# def replace(enum)
|
|
# enum.respond_to?(:each) or raise ArgumentError, "value must be enumerable"
|
|
# clear
|
|
# enum.each_entry { |o| add(o) }
|
|
#
|
|
# self
|
|
# end
|
|
#
|
|
# def merge(enum)
|
|
# enum.respond_to?(:each) or raise ArgumentError, "value must be enumerable"
|
|
# enum.each_entry { |o| add(o) }
|
|
#
|
|
# self
|
|
# end
|
|
# }
|
|
# else
|
|
# instance_eval %{
|
|
# def add(o)
|
|
# if @proc.call(o)
|
|
# @hash[o] = true
|
|
# end
|
|
# self
|
|
# end
|
|
# alias << add
|
|
#
|
|
# def add?(o)
|
|
# if include?(o) || !@proc.call(o)
|
|
# nil
|
|
# else
|
|
# @hash[o] = true
|
|
# self
|
|
# end
|
|
# end
|
|
# }
|
|
# end
|
|
#
|
|
# super(*args)
|
|
# end
|
|
#
|
|
# def restriction_proc
|
|
# @proc
|
|
# end
|
|
# end
|
|
|
|
# Tests have been moved to test/test_set.rb.
|