In Files
- set.rb
Parent
Object
Methods
- ::[]
- ::new
- #&
- #+
- #-
- #<
- #<<
- #<=
- #==
- #>
- #>=
- #^
- #add
- #add?
- #classify
- #clear
- #collect!
- #delete
- #delete?
- #delete_if
- #difference
- #divide
- #each
- #empty?
- #flatten
- #flatten!
- #include?
- #initialize_copy
- #inspect
- #intersection
- #keep_if
- #length
- #map!
- #member?
- #merge
- #proper_subset?
- #proper_superset?
- #reject!
- #replace
- #select!
- #size
- #subset?
- #subtract
- #superset?
- #to_a
- #union
- #|
Included Modules
Class/Module Index
![[+]](./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.
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.
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.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 set.rb, line 64
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 set.rb, line 73
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 set.rb, line 350
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 set.rb, line 343
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 set.rb, line 368
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 set.rb, line 360
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 set.rb, line 238
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 set.rb, line 246
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 set.rb, line 402
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 set.rb, line 131
def clear
@hash.clear
self
end
Replaces the elements with ones returned by collect().
# File set.rb, line 288
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 set.rb, line 256
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 263
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 set.rb, line 273
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 set.rb, line 431
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 set.rb, line 230
def each(&block)
block or return enum_for(__method__)
@hash.each_key(&block)
self
end
Returns true if the set contains no elements.
# File set.rb, line 126
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 175
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 181
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 set.rb, line 190
def include?(o)
@hash.include?(o)
end
Copy internal hash.
# File set.rb, line 97
def initialize_copy(orig)
@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 465
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 set.rb, line 281
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 set.rb, line 316
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 220
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 set.rb, line 204
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 #delete_if, but returns nil if no changes were made.
# File set.rb, line 298
def reject!(&block)
block or return enum_for(__method__)
n = size
delete_if(&block)
size == n ? nil : self
end
Replaces the contents of the set with the contents of the given enumerable object and returns self.
# File set.rb, line 138
def replace(enum)
if enum.instance_of?(self.class)
@hash.replace(enum.instance_variable_get(:@hash))
else
clear
merge(enum)
end
self
end
Equivalent to #keep_if, but returns nil if no changes were made.
# File set.rb, line 307
def select!(&block)
block or return enum_for(__method__)
n = size
keep_if(&block)
size == n ? nil : self
end
Returns the number of elements.
# File set.rb, line 120
def size
@hash.size
end
Returns true if the set is a subset of the given set.
# File set.rb, line 212
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 set.rb, line 328
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 196
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