Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://docs.ruby-lang.org/en/3.4/RubyVM/../syntax/../Set.html below:

class Set - Documentation for Ruby 3.4

This library provides the Set class, which implements a collection of unordered values with no duplicates. It is a hybrid of Array’s intuitive inter-operation facilities and Hash’s fast lookup.

The method to_set is added to Enumerable for convenience.

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:

• Equality of elements is determined according to Object#eql? and Object#hash. Use Set#compare_by_identity to make a set compare its elements by their identity.

• 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.

• When a string is to be stored, a frozen copy of the string is stored instead unless the original string is already frozen.

The comparison operators <, >, <=, and >= are implemented as shorthand for the {proper_,}{subset?,superset?} methods. The <=> operator reflects this order, or return nil for sets that both have distinct elements ({x, y} vs. {x, z} for example).

require 'set'
s1 = Set[1, 2]                        
s2 = [1, 2].to_set                    
s1 == s2                              
s1.add("foo")                         
s1.merge([2, 6])                      
s1.subset?(s2)                        
s2.subset?(s1)                        

• Akinori MUSHA <knu@iDaemons.org> (current maintainer)

First, what’s elsewhere. Class Set:

• Inherits from class Object.

• Includes module Enumerable, which provides dozens of additional methods.

In particular, class Set does not have many methods of its own for fetching or for iterating. Instead, it relies on those in Enumerable.

Here, class Set provides methods that are useful for:

• Creating a Set

• Set Operations

• Comparing

• Querying

• Assigning

• Deleting

• Converting

• Iterating

• And more.…

• ::[]: Returns a new set containing the given objects.

• ::new: Returns a new set containing either the given objects (if no block given) or the return values from the called block (if a block given).

• | (aliased as union and +): Returns a new set containing all elements from self and all elements from a given enumerable (no duplicates).

• & (aliased as intersection): Returns a new set containing all elements common to self and a given enumerable.

• - (aliased as difference): Returns a copy of self with all elements in a given enumerable removed.

• ^: Returns a new set containing all elements from self and a given enumerable except those common to both.

• <=>: Returns -1, 0, or 1 as self is less than, equal to, or greater than a given object.

• ==: Returns whether self and a given enumerable are equal, as determined by Object#eql?.

• compare_by_identity?: Returns whether the set considers only identity when comparing elements.

• length (aliased as size): Returns the count of elements.

• empty?: Returns whether the set has no elements.

• include? (aliased as member? and ===): Returns whether a given object is an element in the set.

• subset? (aliased as <=): Returns whether a given object is a subset of the set.

• proper_subset? (aliased as <): Returns whether a given enumerable is a proper subset of the set.

• superset? (aliased as >=]): Returns whether a given enumerable is a superset of the set.

• proper_superset? (aliased as >): Returns whether a given enumerable is a proper superset of the set.

• disjoint?: Returns true if the set and a given enumerable have no common elements, false otherwise.

• intersect?: Returns true if the set and a given enumerable: have any common elements, false otherwise.

• compare_by_identity?: Returns whether the set considers only identity when comparing elements.

• add (aliased as <<): Adds a given object to the set; returns self.

• add?: If the given object is not an element in the set, adds it and returns self; otherwise, returns nil.

• merge: Merges the elements of each given enumerable object to the set; returns self.

• replace: Replaces the contents of the set with the contents of a given enumerable.

• clear: Removes all elements in the set; returns self.

• delete: Removes a given object from the set; returns self.

• delete?: If the given object is an element in the set, removes it and returns self; otherwise, returns nil.

• subtract: Removes each given object from the set; returns self.

• delete_if - Removes elements specified by a given block.

• select! (aliased as filter!): Removes elements not specified by a given block.

• keep_if: Removes elements not specified by a given block.

• reject! Removes elements specified by a given block.

• classify: Returns a hash that classifies the elements, as determined by the given block.

• collect! (aliased as map!): Replaces each element with a block return-value.

• divide: Returns a hash that classifies the elements, as determined by the given block; differs from classify in that the block may accept either one or two arguments.

• flatten: Returns a new set that is a recursive flattening of self. flatten!: Replaces each nested set in self with the elements from that set.

• inspect (aliased as to_s): Returns a string displaying the elements.

• join: Returns a string containing all elements, converted to strings as needed, and joined by the given record separator.

• to_a: Returns an array containing all set elements.

• to_set: Returns self if given no arguments and no block; with a block given, returns a new set consisting of block return values.

• each: Calls the block with each successive element; returns self.

• reset: Resets the internal state; useful if an object has been modified while an element in the set.

VERSION

def self.[](*ary)
  new(ary)
end

Creates a new set containing the given objects.

Set[1, 2]                   
Set[1, 2, 1]                
Set[1, 'c', :s]             

def self.json_create(object)
  new object['a']
end

See as_json.

def initialize(enum = nil, &block) 
  @hash ||= Hash.new(false)

  enum.nil? and return

  if block
    do_with_enum(enum) { |o| add(block[o]) }
  else
    merge(enum)
  end
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.new([1, 2, 1])                    
Set.new([1, 'c', :s])                 
Set.new(1..5)                         
Set.new([1, 2, 3]) { |x| x * x }      

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 containing elements common to the set and the given enumerable object.

Set[1, 3, 5] & Set[3, 2, 1]             
Set['a', 'b', 'z'] & ['a', 'b', 'c']    

def -(enum)
  dup.subtract(enum)
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['a', 'b', 'z'] - ['a', 'c']         

def <=>(set)
  return unless set.is_a?(Set)

  case size <=> set.size
  when -1 then -1 if proper_subset?(set)
  when +1 then +1 if proper_superset?(set)
  else 0 if self.==(set)
  end
end

Returns 0 if the set are equal, -1 / +1 if the set is a proper subset / superset of the given set, or nil if they both have unique elements.

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 two sets are equal. The equality of each couple of elements is defined according to Object#eql?.

Set[1, 2] == Set[2, 1]                       
Set[1, 3, 5] == Set[1, 5]                    
Set['a', 'b', 'c'] == Set['a', 'c', 'b']     
Set['a', 'b', 'c'] == ['a', 'c', 'b']        

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

Or by itself:

Set[1, 2, 3] === 2   
Set[1, 2, 3] === 4   

def ^(enum)
  n = self.class.new(enum)
  each { |o| n.add(o) unless n.delete?(o) }
  n
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)).

Set[1, 2] ^ Set[2, 3]                   
Set[1, 'b', 'c'] ^ ['b', 'd']           

def |(enum)
  dup.merge(enum)
end

Returns a new set built by merging the set and the elements of the given enumerable object.

Set[1, 2, 3] | Set[2, 4, 5]         
Set[1, 5, 'z'] | (1..6)             

def add(o)
  @hash[o] = true
  self
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].add([3, 4])               
Set[1, 2].add(2)                    

def add?(o)
  add(o) unless include?(o)
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].add?([3, 4])               
Set[1, 2].add?(2)                    

def as_json(*)
  {
    JSON.create_id => self.class.name,
    'a'            => to_a,
  }
end

Methods Set#as_json and Set.json_create may be used to serialize and deserialize a Set object; see Marshal.

Method Set#as_json serializes self, returning a 2-element hash representing self:

require 'json/add/set'
x = Set.new(%w/foo bar baz/).as_json

Method JSON.create deserializes such a hash, returning a Set object:

Set.json_create(x) 

def classify 
  block_given? or return enum_for(__method__) { size }

  h = {}

  each { |i|
    (h[yield(i)] ||= self.class.new).add(i)
  }

  h
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       
           
           

Returns an enumerator if no block is given.

def clear
  @hash.clear
  self
end

Removes all elements and returns self.

set = Set[1, 'c', :s]             
set.clear                         
set                               

def collect!
  block_given? or return enum_for(__method__) { size }
  set = self.class.new
  each { |o| set << yield(o) }
  replace(set)
end

Replaces the elements with ones returned by collect(). Returns an enumerator if no block is given.

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

Makes the set compare its elements by their identity and returns self. This method may not be supported by all subclasses of Set.

def compare_by_identity?
  @hash.respond_to?(:compare_by_identity?) && @hash.compare_by_identity?
end

Returns true if the set will compare its elements by their identity. Also see Set#compare_by_identity.

def delete(o)
  @hash.delete(o)
  self
end

Deletes the given object from the set and returns self. Use subtract to delete many items at once.

def delete?(o)
  delete(o) if include?(o)
end

Deletes the given object from the set and returns self. If the object is not in the set, returns nil.

def delete_if(&block)
  block_given? or return enum_for(__method__) { size }
  
  
  select(&block).each { |o| @hash.delete(o) }
  self
end

Deletes every element of the set for which block evaluates to true, and returns self. Returns an enumerator if no block is given.

def disjoint?(set)
  !intersect?(set)
end

Returns true if the set and the given enumerable have no element in common. This method is the opposite of intersect?.

Set[1, 2, 3].disjoint? Set[3, 4]   
Set[1, 2, 3].disjoint? Set[4, 5]   
Set[1, 2, 3].disjoint? [3, 4]      
Set[1, 2, 3].disjoint? 4..5        

def divide(&func)
  func or return enum_for(__method__) { size }

  if func.arity == 2
    require 'tsort'

    class << dig = {}         
      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

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        
           
           
           

Returns an enumerator if no block is given.

def each(&block)
  block_given? or return enum_for(__method__) { size }
  @hash.each_key(&block)
  self
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.

def empty?
  @hash.empty?
end

Returns true if the set contains no elements.

def flatten
  self.class.new.flatten_merge(self)
end

Returns a new set that is a copy of the set, flattening each containing set recursively.

def flatten!
  replace(flatten()) if any?(Set)
end

Equivalent to Set#flatten, but replaces the receiver with the result in place. Returns nil if no modifications were made.

def include?(o)
  @hash[o]
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?

def initialize_clone(orig, **options)
  super
  @hash = orig.instance_variable_get(:@hash).clone(**options)
end

Clone internal hash.

Calls superclass method

def initialize_dup(orig)
  super
  @hash = orig.instance_variable_get(:@hash).dup
end

Dup internal hash.

Calls superclass method

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 a string containing a human-readable representation of the set (“#<Set: {element1, element2, …}>”).

def intersect?(set)
  case set
  when Set
    if size < set.size
      any?(set)
    else
      set.any?(self)
    end
  when Enumerable
    set.any?(self)
  else
    raise ArgumentError, "value must be enumerable"
  end
end

Returns true if the set and the given enumerable have at least one element in common.

Set[1, 2, 3].intersect? Set[4, 5]   
Set[1, 2, 3].intersect? Set[3, 4]   
Set[1, 2, 3].intersect? 4..5        
Set[1, 2, 3].intersect? [3, 4]      

def join(separator=nil)
  to_a.join(separator)
end

Returns a string created by converting each element of the set to a string See also: Array#join

def keep_if(&block)
  block_given? or return enum_for(__method__) { size }
  
  
  reject(&block).each { |o| @hash.delete(o) }
  self
end

Deletes every element of the set for which block evaluates to false, and returns self. Returns an enumerator if no block is given.

def merge(*enums, **nil)
  enums.each do |enum|
    if enum.instance_of?(self.class)
      @hash.update(enum.instance_variable_get(:@hash))
    else
      do_with_enum(enum) { |o| add(o) }
    end
  end

  self
end

Merges the elements of the given enumerable objects to the set and returns self.

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?(set)
  else
    raise ArgumentError, "value must be a set"
  end
end

Returns true if the set is a proper subset of the given set.

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?(self)
  else
    raise ArgumentError, "value must be a set"
  end
end

Returns true if the set is a proper superset of the given set.

def reject!(&block)
  block_given? or return enum_for(__method__) { size }
  n = size
  delete_if(&block)
  self if size != n
end

Equivalent to Set#delete_if, but returns nil if no changes were made. Returns an enumerator if no block is given.

def replace(enum)
  if enum.instance_of?(self.class)
    @hash.replace(enum.instance_variable_get(:@hash))
    self
  else
    do_with_enum(enum)  
    clear
    merge(enum)
  end
end

Replaces the contents of the set with the contents of the given enumerable object and returns self.

set = Set[1, 'c', :s]             
set.replace([1, 2])               
set                               

def reset
  if @hash.respond_to?(:rehash)
    @hash.rehash 
  else
    raise FrozenError, "can't modify frozen #{self.class.name}" if frozen?
  end
  self
end

Resets the internal state after modification to existing elements and returns self.

Elements will be reindexed and deduplicated.

def select!(&block)
  block_given? or return enum_for(__method__) { size }
  n = size
  keep_if(&block)
  self if size != n
end

Equivalent to Set#keep_if, but returns nil if no changes were made. Returns an enumerator if no block is given.

Returns the number of elements.

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?(set)
  else
    raise ArgumentError, "value must be a set"
  end
end

Returns true if the set is a subset of the given set.

def subtract(enum)
  do_with_enum(enum) { |o| delete(o) }
  self
end

Deletes every element that appears in the given enumerable object and returns self.

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?(self)
  else
    raise ArgumentError, "value must be a set"
  end
end

Returns true if the set is a superset of the given set.

Returns an array containing all elements in the set.

Set[1, 2].to_a                    
Set[1, 'c', :s].to_a              

def to_json(*args)
  as_json.to_json(*args)
end

Returns a JSON string representing self:

require 'json/add/set'
puts Set.new(%w/foo bar baz/).to_json

Output:

{"json_class":"Set","a":["foo","bar","baz"]}

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

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.

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4