struct Set(T)
Overview
Set
implements a collection of unordered values with no duplicates.
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#==
andObject#hash
. 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.
Example
s1 = Set{1, 2}
s2 = [1, 2].to_set
s3 = Set.new [1, 2]
s1 == s2 # => true
s1 == s3 # => true
s1.add(2)
s1.concat([6, 8])
s1.subset_of? s2 # => false
s2.subset_of? s1 # => true
Included Modules
Defined in:
json/to_json.crset.cr
yaml/to_yaml.cr
Constructors
-
.additive_identity : self
Returns the additive identity of this type.
- .new(ctx : YAML::ParseContext, node : YAML::Nodes::Node)
- .new(other : Indexable(T))
-
.new(enumerable : Enumerable(T))
Creates a new set from the elements in enumerable.
- .new(pull : JSON::PullParser)
-
.new(initial_capacity = nil)
Creates a new, empty
Set
. - .new(ctx : YAML::ParseContext, node : YAML::Nodes::Node, &)
Instance Method Summary
-
#&(other : Set) : Set(T)
Intersection: returns a new set containing elements common to both sets.
-
#+(other : Set(U)) : Set(T | U) forall U
Addition: returns a new set containing the unique elements from both sets.
-
#-(other : Set) : Set(T)
Difference: returns a new set containing elements in this set that are not present in the other.
-
#-(other : Enumerable) : Set(T)
Difference: returns a new set containing elements in this set that are not present in the other enumerable.
-
#<<(object : T) : self
Alias for
#add
-
#==(other : Set) : Bool
Returns
true
if both sets have the same elements. -
#===(object : T) : Bool
Same as
#includes?
. -
#^(other : Set(U)) : Set(T | U) forall U
Symmetric Difference: returns a new set
(self - other) | (other - self)
. -
#^(other : Enumerable(U)) : Set(T | U) forall U
Symmetric Difference: returns a new set
(self - other) | (other - self)
. -
#|(other : Set(U)) : Set(T | U) forall U
Union: returns a new set containing all unique elements from both sets.
-
#add(object : T) : self
Adds object to the set and returns
self
. -
#add?(object : T) : Bool
Adds object to the set and returns
true
on success andfalse
if the value was already in the set. -
#clear : self
Removes all elements in the set, and returns
self
. -
#clone : Set(T)
Returns a new
Set
with all of the elements cloned. - #compare_by_identity : self
-
#compare_by_identity? : Bool
Returns
true
if this Set is comparing objects byobject_id
. -
#concat(elems) : self
Adds
#each
element of elems to the set and returnsself
. -
#delete(object) : Bool
Removes the object from the set and returns
true
if it was present, otherwise returnsfalse
. -
#dup : Set(T)
Returns a new
Set
with all of the same elements. -
#each(& : T -> ) : Nil
Yields each element of the set, and returns
nil
. -
#each
Returns an iterator for each element of the set.
-
#empty? : Bool
Returns
true
if the set is empty. - #hash(hasher)
-
#includes?(object) : Bool
Returns
true
if object exists in the set. -
#inspect(io : IO) : Nil
Alias of
#to_s
. -
#intersects?(other : Set) : Bool
Returns
true
if the set and the given set have at least one element in common. - #pretty_print(pp) : Nil
-
#proper_subset_of?(other : Set) : Bool
Returns
true
if the set is a proper subset of the other set. -
#proper_superset_of?(other : Set) : Bool
Returns
true
if the set is a superset of the other set. -
#rehash : Nil
Rebuilds the set based on the current elements.
-
#size : Int32
Returns the number of elements in the set.
-
#subset_of?(other : Set) : Bool
Returns
true
if the set is a subset of the other set. -
#subtract(other : Enumerable) : self
Returns
self
after removing from it those elements that are present in the given enumerable. -
#superset_of?(other : Set) : Bool
Returns
true
if the set is a superset of the other set. -
#to_a : Array(T)
Returns the elements as an
Array
. -
#to_a(& : T -> U) : Array(U) forall U
Returns an
Array
with the results of running block against each element of the collection. - #to_json(json : JSON::Builder) : Nil
-
#to_s(io : IO) : Nil
Writes a string representation of the set to io.
- #to_yaml(yaml : YAML::Nodes::Builder) : Nil
Instance methods inherited from module Iterable(T)
chunk(reuse = false, &block : T -> U) forall U
chunk,
chunk_while(reuse : Bool | Array(T) = false, &block : T, T -> B) forall B
chunk_while,
cycle(n)cycle cycle, each each, each_cons(count : Int, reuse = false) each_cons, each_cons_pair each_cons_pair, each_slice(count : Int, reuse = false) each_slice, each_step(n : Int)
each_step(n : Int, *, offset : Int) each_step, each_with_index(offset = 0) each_with_index, each_with_object(obj) each_with_object, slice_after(reuse : Bool | Array(T) = false, &block : T -> B) forall B
slice_after(pattern, reuse : Bool | Array(T) = false) slice_after, slice_before(reuse : Bool | Array(T) = false, &block : T -> B) forall B
slice_before(pattern, reuse : Bool | Array(T) = false) slice_before, slice_when(reuse : Bool | Array(T) = false, &block : T, T -> B) forall B slice_when
Instance methods inherited from module Enumerable(T)
accumulate(initial : U) : Array(U) forall Uaccumulate : Array(T)
accumulate(initial : U, &block : U, T -> U) : Array(U) forall U
accumulate(&block : T, T -> T) : Array(T) accumulate, all?(& : T -> ) : Bool
all?(pattern) : Bool
all? : Bool all?, any?(& : T -> ) : Bool
any?(pattern) : Bool
any? : Bool any?, chunks(&block : T -> U) forall U chunks, compact_map(& : T -> _) compact_map, count(& : T -> ) : Int32
count(item) : Int32 count, cycle(n, & : T -> ) : Nil
cycle(& : T -> ) : Nil cycle, each(& : T -> ) each, each_cons(count : Int, reuse = false, &) each_cons, each_cons_pair(& : T, T -> ) : Nil each_cons_pair, each_slice(count : Int, reuse = false, &) each_slice, each_step(n : Int, *, offset : Int = 0, & : T -> ) : Nil each_step, each_with_index(offset = 0, &) each_with_index, each_with_object(obj : U, & : T, U -> ) : U forall U each_with_object, empty? : Bool empty?, find(if_none = nil, & : T -> ) find, find!(& : T -> ) : T find!, find_value(if_none = nil, & : T -> ) find_value, first(&)
first(count : Int) : Array(T)
first : T first, first? : T | Nil first?, flat_map(& : T -> _) flat_map, group_by(& : T -> U) forall U group_by, in_groups_of(size : Int, filled_up_with : U = nil) forall U
in_groups_of(size : Int, filled_up_with : U = nil, reuse = false, &) forall U in_groups_of, in_slices_of(size : Int) : Array(Array(T)) in_slices_of, includes?(obj) : Bool includes?, index(& : T -> ) : Int32 | Nil
index(obj) : Int32 | Nil index, index!(& : T -> ) : Int32
index!(obj) : Int32 index!, index_by(& : T -> U) : Hash(U, T) forall U index_by, join(io : IO, separator = "") : Nil
join(separator, io : IO) : Nil
join(separator = "") : String
join(io : IO, separator = "", & : T, IO -> )
join(separator, io : IO, &)
join(separator = "", & : T -> ) join, map(& : T -> U) : Array(U) forall U map, map_with_index(offset = 0, & : T, Int32 -> U) : Array(U) forall U map_with_index, max(count : Int) : Array(T)
max : T max, max? : T | Nil max?, max_by(& : T -> U) : T forall U max_by, max_by?(& : T -> U) : T | Nil forall U max_by?, max_of(& : T -> U) : U forall U max_of, max_of?(& : T -> U) : U | Nil forall U max_of?, min(count : Int) : Array(T)
min : T min, min? : T | Nil min?, min_by(& : T -> U) : T forall U min_by, min_by?(& : T -> U) : T | Nil forall U min_by?, min_of(& : T -> U) : U forall U min_of, min_of?(& : T -> U) : U | Nil forall U min_of?, minmax : Tuple(T, T) minmax, minmax? : Tuple(T | Nil, T | Nil) minmax?, minmax_by(& : T -> U) : Tuple(T, T) forall U minmax_by, minmax_by?(& : T -> U) : Tuple(T, T) | Tuple(Nil, Nil) forall U minmax_by?, minmax_of(& : T -> U) : Tuple(U, U) forall U minmax_of, minmax_of?(& : T -> U) : Tuple(U, U) | Tuple(Nil, Nil) forall U minmax_of?, none?(& : T -> ) : Bool
none?(pattern) : Bool
none? : Bool none?, one?(& : T -> ) : Bool
one?(pattern) : Bool
one? : Bool one?, partition(& : T -> ) : Tuple(Array(T), Array(T))
partition(type : U.class) forall U partition, present? : Bool present?, product(initial : Number)
product
product(initial : Number, & : T -> )
product(& : T -> _) product, reduce(memo, &)
reduce(&) reduce, reduce?(&) reduce?, reject(& : T -> )
reject(type : U.class) forall U
reject(pattern) : Array(T) reject, sample(n : Int, random : Random = Random::DEFAULT) : Array(T)
sample(random : Random = Random::DEFAULT) : T sample, select(& : T -> )
select(type : U.class) : Array(U) forall U
select(pattern) : Array(T) select, size : Int32 size, skip(count : Int) skip, skip_while(& : T -> ) : Array(T) skip_while, sum(initial)
sum
sum(initial, & : T -> )
sum(& : T -> ) sum, take_while(& : T -> ) : Array(T) take_while, tally(hash)
tally : Hash(T, Int32) tally, tally_by(hash, &)
tally_by(&block : T -> U) : Hash(U, Int32) forall U tally_by, to_a : Array(T)
to_a(& : T -> U) : Array(U) forall U to_a, to_h
to_h(& : T -> Tuple(K, V)) forall K, V to_h, to_set : Set(T)
to_set(&block : T -> U) : Set(U) forall U to_set, zip(*others : Indexable | Iterable | Iterator, &)
zip(*others : Indexable | Iterable | Iterator) zip, zip?(*others : Indexable | Iterable | Iterator, &)
zip?(*others : Indexable | Iterable | Iterator) zip?
Class methods inherited from module Enumerable(T)
element_type(x)
element_type
Instance methods inherited from struct Struct
==(other) : Bool
==,
hash(hasher)
hash,
inspect(io : IO) : Nil
inspect,
pretty_print(pp) : Nil
pretty_print,
to_s(io : IO) : Nil
to_s
Instance methods inherited from struct Value
==(other : JSON::Any)==(other : YAML::Any)
==(other) ==, dup dup
Instance methods inherited from class Object
! : Bool
!,
!=(other)
!=,
!~(other)
!~,
==(other)
==,
===(other : JSON::Any)===(other : YAML::Any)
===(other) ===, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, inspect(io : IO) : Nil
inspect : String inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil!(message)
not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as
Class methods inherited from class Object
from_json(string_or_io, root : String)from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml
Macros inherited from class Object
class_getter(*names, &block)
class_getter,
class_getter!(*names)
class_getter!,
class_getter?(*names, &block)
class_getter?,
class_property(*names, &block)
class_property,
class_property!(*names)
class_property!,
class_property?(*names, &block)
class_property?,
class_setter(*names)
class_setter,
def_clone
def_clone,
def_equals(*fields)
def_equals,
def_equals_and_hash(*fields)
def_equals_and_hash,
def_hash(*fields)
def_hash,
delegate(*methods, to object)
delegate,
forward_missing_to(delegate)
forward_missing_to,
getter(*names, &block)
getter,
getter!(*names)
getter!,
getter?(*names, &block)
getter?,
property(*names, &block)
property,
property!(*names)
property!,
property?(*names, &block)
property?,
setter(*names)
setter
Constructor Detail
Returns the additive identity of this type.
This is an empty set.
Creates a new set from the elements in enumerable.
a = [1, 3, 5]
s = Set.new a
s.empty? # => false
Creates a new, empty Set
.
s = Set(Int32).new
s.empty? # => true
An initial capacity can be specified, and it will be set as the initial capacity
of the internal Hash
.
Instance Method Detail
Intersection: returns a new set containing elements common to both sets.
Set{1, 1, 3, 5} & Set{1, 2, 3} # => Set{1, 3}
Set{'a', 'b', 'b', 'z'} & Set{'a', 'b', 'c'} # => Set{'a', 'b'}
Addition: returns a new set containing the unique elements from both sets.
Set{1, 1, 2, 3} + Set{3, 4, 5} # => Set{1, 2, 3, 4, 5}
Difference: returns a new set containing elements in this set that are not present in the other.
Set{1, 2, 3, 4, 5} - Set{2, 4} # => Set{1, 3, 5}
Set{'a', 'b', 'b', 'z'} - Set{'a', 'b', 'c'} # => Set{'z'}
Difference: returns a new set containing elements in this set that are not present in the other enumerable.
Set{1, 2, 3, 4, 5} - [2, 4] # => Set{1, 3, 5}
Set{'a', 'b', 'b', 'z'} - ['a', 'b', 'c'] # => Set{'z'}
Returns true
if both sets have the same elements.
Set{1, 5} == Set{1, 5} # => true
Same as #includes?
.
It is for convenience with using on case
statement.
red_like = Set{"red", "pink", "violet"}
blue_like = Set{"blue", "azure", "violet"}
case "violet"
when red_like & blue_like
puts "red & blue like color!"
when red_like
puts "red like color!"
when blue_like
puts "blue like color!"
end
See also: Object#===
.
Symmetric Difference: returns a new set (self - other) | (other - self)
.
Equivalently, returns (self | other) - (self & other)
.
Set{1, 2, 3, 4, 5} ^ Set{2, 4, 6} # => Set{1, 3, 5, 6}
Set{'a', 'b', 'b', 'z'} ^ Set{'a', 'b', 'c'} # => Set{'z', 'c'}
Symmetric Difference: returns a new set (self - other) | (other - self)
.
Equivalently, returns (self | other) - (self & other)
.
Set{1, 2, 3, 4, 5} ^ [2, 4, 6] # => Set{1, 3, 5, 6}
Set{'a', 'b', 'b', 'z'} ^ ['a', 'b', 'c'] # => Set{'z', 'c'}
Union: returns a new set containing all unique elements from both sets.
Set{1, 1, 3, 5} | Set{1, 2, 3} # => Set{1, 3, 5, 2}
Set{'a', 'b', 'b', 'z'} | Set{'a', 'b', 'c'} # => Set{'a', 'b', 'z', 'c'}
See also: #concat
to add elements from a set to self
.
Adds object to the set and returns self
.
s = Set{1, 5}
s.includes? 8 # => false
s.add(8)
s.includes? 8 # => true
Adds object to the set and returns true
on success
and false
if the value was already in the set.
s = Set{1, 5}
s.add? 8 # => true
s.add? 8 # => false
Removes all elements in the set, and returns self
.
s = Set{1, 5}
s.size # => 2
s.clear
s.size # => 0
Makes this set compare objects using their object identity (object_id)
for types that define such method (Reference
types, but also structs that
might wrap other Reference
types and delegate the object_id
method to them).
s = Set{"foo", "bar"}
s.includes?("fo" + "o") # => true
s.compare_by_identity
s.compare_by_identity? # => true
s.includes?("fo" + "o") # => false # not the same String instance
Returns true
if this Set is comparing objects by object_id
.
See #compare_by_identity
.
Adds #each
element of elems to the set and returns self
.
s = Set{1, 5}
s.concat [5, 5, 8, 9]
s.size # => 4
See also: #|
to merge two sets and return a new one.
Removes the object from the set and returns true
if it was present, otherwise returns false
.
s = Set{1, 5}
s.includes? 5 # => true
s.delete 5 # => true
s.includes? 5 # => false
s.delete 5 # => false
Returns true
if the set is empty.
s = Set(Int32).new
s.empty? # => true
s << 3
s.empty? # => false
Returns true
if object exists in the set.
s = Set{1, 5}
s.includes? 5 # => true
s.includes? 9 # => false
Returns true
if the set and the given set have at least one element in
common.
Set{1, 2, 3}.intersects? Set{4, 5} # => false
Set{1, 2, 3}.intersects? Set{3, 4} # => true
Returns true
if the set is a proper subset of the other set.
This set must have fewer elements than the other set, and all of elements in this set must be present in the other set.
Set{1, 5}.proper_subset_of? Set{1, 3, 5} # => true
Set{1, 3, 5}.proper_subset_of? Set{1, 3, 5} # => false
Returns true
if the set is a superset of the other set.
The other must have fewer elements than this set, and all of elements in the other set must be present in this set.
Set{1, 3, 5}.proper_superset_of? Set{1, 5} # => true
Set{1, 3, 5}.proper_superset_of? Set{1, 3, 5} # => false
Rebuilds the set based on the current elements.
When using mutable data types as elements, modifying an elements after it
was inserted into the Set
may lead to undefined behaviour. This method
re-indexes the set using the current elements.
Returns the number of elements in the set.
s = Set{1, 5}
s.size # => 2
Returns true
if the set is a subset of the other set.
This set must have the same or fewer elements than the other set, and all of elements in this set must be present in the other set.
Set{1, 5}.subset_of? Set{1, 3, 5} # => true
Set{1, 3, 5}.subset_of? Set{1, 3, 5} # => true
Returns self
after removing from it those elements that are present in
the given enumerable.
Set{'a', 'b', 'b', 'z'}.subtract Set{'a', 'b', 'c'} # => Set{'z'}
Set{1, 2, 3, 4, 5}.subtract [2, 4, 6] # => Set{1, 3, 5}
Returns true
if the set is a superset of the other set.
The other must have the same or fewer elements than this set, and all of elements in the other set must be present in this set.
Set{1, 3, 5}.superset_of? Set{1, 5} # => true
Set{1, 3, 5}.superset_of? Set{1, 3, 5} # => true
Returns an Array
with the results of running block against each element of the collection.
Set{1, 2, 3, 4, 5}.to_a { |i| i // 2 } # => [0, 1, 1, 2, 2]