+3.1.4

+ruby-immutable-ruby (0.2.0-1) unstable; urgency=medium

+

+ * Team upload.

+

+ [ Lucas Nussbaum ]

+ * debian/gbp.conf: Add for DEP-14

+ * debian/gbp.conf: remove trailing empty lines

+ * debian/salsa-ci.yml: use team-specific include

+

+ [ Simon Quigley ]

+ * Upgrade the watch file to version 5.

+ * New upstream release.

+ * Update Standards-Version to 4.7.3.

+ * Drop Rules-Requires-Root field, it is now redundant.

+

+ -- Simon Quigley <tsimonq2@debian.org> Tue, 03 Mar 2026 11:38:55 -0600

+

+Standards-Version: 4.7.3

+[DEFAULT]

+debian-branch = debian/latest

+upstream-branch = upstream/latest

+pristine-tar = True

+ - https://salsa.debian.org/ruby-team/meta/raw/master/salsa-ci.yml

+Version: 5

+Template: GitHub

+Owner: immutable-ruby

+Project: immutable-ruby

+Uversion-Mangle: auto

+require 'immutable/undefined'

+require 'immutable/enumerable'

+require 'immutable/trie'

+require 'immutable/sorted_set'

+require 'set'

+

+module Immutable

+

+ # An `Immutable::Hash` maps a set of unique keys to corresponding values, much

+ # like a dictionary maps from words to definitions. Given a key, it can store

+ # and retrieve an associated value in constant time. If an existing key is

+ # stored again, the new value will replace the old. It behaves much like

+ # Ruby's built-in Hash, which we will call RubyHash for clarity. Like

+ # RubyHash, two keys that are `#eql?` to each other and have the same

+ # `#hash` are considered identical in an `Immutable::Hash`.

+ #

+ # An `Immutable::Hash` can be created in a couple of ways:

+ #

+ # Immutable::Hash.new(font_size: 10, font_family: 'Arial')

+ # Immutable::Hash[first_name: 'John', last_name: 'Smith']

+ #

+ # Any `Enumerable` object which yields two-element `[key, value]` arrays

+ # can be used to initialize an `Immutable::Hash`:

+ #

+ # Immutable::Hash.new([[:first_name, 'John'], [:last_name, 'Smith']])

+ #

+ # Key/value pairs can be added using {#put}. A new hash is returned and the

+ # existing one is left unchanged:

+ #

+ # hash = Immutable::Hash[a: 100, b: 200]

+ # hash.put(:c, 500) # => Immutable::Hash[:a => 100, :b => 200, :c => 500]

+ # hash # => Immutable::Hash[:a => 100, :b => 200]

+ #

+ # {#put} can also take a block, which is used to calculate the value to be

+ # stored.

+ #

+ # hash.put(:a) { |current| current + 200 } # => Immutable::Hash[:a => 300, :b => 200]

+ #

+ # Since it is immutable, all methods which you might expect to "modify" a

+ # `Immutable::Hash` actually return a new hash and leave the existing one

+ # unchanged. This means that the `hash[key] = value` syntax from RubyHash

+ # *cannot* be used with `Immutable::Hash`.

+ #

+ # Nested data structures can easily be updated using {#update_in}:

+ #

+ # hash = Immutable::Hash["a" => Immutable::Vector[Immutable::Hash["c" => 42]]]

+ # hash.update_in("a", 0, "c") { |value| value + 5 }

+ # # => Immutable::Hash["a" => Immutable::Hash["b" => Immutable::Hash["c" => 47]]]

+ #

+ # While an `Immutable::Hash` can iterate over its keys or values, it does not

+ # guarantee any specific iteration order (unlike RubyHash). Methods like

+ # {#flatten} do not guarantee the order of returned key/value pairs.

+ #

+ # Like RubyHash, an `Immutable::Hash` can have a default block which is used

+ # when looking up a key that does not exist. Unlike RubyHash, the default

+ # block will only be passed the missing key, without the hash itself:

+ #

+ # hash = Immutable::Hash.new { |missing_key| missing_key * 10 }

+ # hash[5] # => 50

+ class Hash

+ include Immutable::Enumerable

+

+ class << self

+ # Create a new `Hash` populated with the given key/value pairs.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2] # => Immutable::Hash["A" => 1, "B" => 2]

+ # Immutable::Hash[["A", 1], ["B", 2]] # => Immutable::Hash["A" => 1, "B" => 2]

+ #

+ # @param pairs [::Enumerable] initial content of hash. An empty hash is returned if not provided.

+ # @return [Hash]

+ def [](pairs = nil)

+ (pairs.nil? || pairs.empty?) ? empty : new(pairs)

+ end

+

+ # Return an empty `Hash`. If used on a subclass, returns an empty instance

+ # of that class.

+ #

+ # @return [Hash]

+ def empty

+ @empty ||= new

+ end

+

+ # "Raw" allocation of a new `Hash`. Used internally to create a new

+ # instance quickly after obtaining a modified {Trie}.

+ #

+ # @return [Hash]

+ # @private

+ def alloc(trie = EmptyTrie, block = nil)

+ obj = allocate

+ obj.instance_variable_set(:@trie, trie)

+ obj.instance_variable_set(:@default, block)

+ obj.freeze

+ end

+ end

+

+ # @param pairs [::Enumerable] initial content of hash. An empty hash is returned if not provided.

+ # @yield [key] Optional _default block_ to be stored and used to calculate the default value of a missing key. It will not be yielded during this method. It will not be preserved when marshalling.

+ # @yieldparam key Key that was not present in the hash.

+ def initialize(pairs = nil, &block)

+ @trie = pairs ? Trie[pairs] : EmptyTrie

+ @default = block

+ freeze

+ end

+

+ # Return the default block if there is one. Otherwise, return `nil`.

+ #

+ # @return [Proc]

+ def default_proc

+ @default

+ end

+

+ # Return the number of key/value pairs in this `Hash`.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].size # => 3

+ #

+ # @return [Integer]

+ def size

+ @trie.size

+ end

+ alias length size

+

+ # Return `true` if this `Hash` contains no key/value pairs.

+ #

+ # @return [Boolean]

+ def empty?

+ @trie.empty?

+ end

+

+ # Return `true` if the given key object is present in this `Hash`. More precisely,

+ # return `true` if a key with the same `#hash` code, and which is also `#eql?`

+ # to the given key object is present.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].key?("B") # => true

+ #

+ # @param key [Object] The key to check for

+ # @return [Boolean]

+ def key?(key)

+ @trie.key?(key)

+ end

+ alias has_key? key?

+ alias include? key?

+ alias member? key?

+

+ # Return `true` if this `Hash` has one or more keys which map to the provided value.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].value?(2) # => true

+ #

+ # @param value [Object] The value to check for

+ # @return [Boolean]

+ def value?(value)

+ each { |k,v| return true if value == v }

+ false

+ end

+ alias has_value? value?

+

+ # Retrieve the value corresponding to the provided key object. If not found, and

+ # this `Hash` has a default block, the default block is called to provide the

+ # value. Otherwise, return `nil`.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h["B"] # => 2

+ # h.get("B") # => 2

+ # h.get("Elephant") # => nil

+ #

+ # # Immutable Hash with a default proc:

+ # h = Immutable::Hash.new("A" => 1, "B" => 2, "C" => 3) { |key| key.size }

+ # h.get("B") # => 2

+ # h.get("Elephant") # => 8

+ #

+ # @param key [Object] The key to look up

+ # @return [Object]

+ def get(key)

+ entry = @trie.get(key)

+ if entry

+ entry[1]

+ elsif @default

+ @default.call(key)

+ end

+ end

+ alias [] get

+

+ # Retrieve the value corresponding to the given key object, or use the provided

+ # default value or block, or otherwise raise a `KeyError`.

+ #

+ # @overload fetch(key)

+ # Retrieve the value corresponding to the given key, or raise a `KeyError`

+ # if it is not found.

+ # @param key [Object] The key to look up

+ # @overload fetch(key) { |key| ... }

+ # Retrieve the value corresponding to the given key, or call the optional

+ # code block (with the missing key) and get its return value.

+ # @yield [key] The key which was not found

+ # @yieldreturn [Object] Object to return since the key was not found

+ # @param key [Object] The key to look up

+ # @overload fetch(key, default)

+ # Retrieve the value corresponding to the given key, or else return

+ # the provided `default` value.

+ # @param key [Object] The key to look up

+ # @param default [Object] Object to return if the key is not found

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.fetch("B") # => 2

+ # h.fetch("Elephant") # => KeyError: key not found: "Elephant"

+ #

+ # # with a default value:

+ # h.fetch("B", 99) # => 2

+ # h.fetch("Elephant", 99) # => 99

+ #

+ # # with a block:

+ # h.fetch("B") { |key| key.size } # => 2

+ # h.fetch("Elephant") { |key| key.size } # => 8

+ #

+ # @return [Object]

+ def fetch(key, default = Undefined)

+ entry = @trie.get(key)

+ if entry

+ entry[1]

+ elsif block_given?

+ yield(key)

+ elsif default != Undefined

+ default

+ else

+ raise KeyError, "key not found: #{key.inspect}"

+ end

+ end

+

+ # Return a new `Hash` with the existing key/value associations, plus an association

+ # between the provided key and value. If an equivalent key is already present, its

+ # associated value will be replaced with the provided one.

+ #

+ # If the `value` argument is missing, but an optional code block is provided,

+ # it will be passed the existing value (or `nil` if there is none) and what it

+ # returns will replace the existing value. This is useful for "transforming"

+ # the value associated with a certain key.

+ #

+ # Avoid mutating objects which are used as keys. `String`s are an exception:

+ # unfrozen `String`s which are used as keys are internally duplicated and

+ # frozen. This matches RubyHash's behaviour.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2]

+ # h.put("C", 3)

+ # # => Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.put("B") { |value| value * 10 }

+ # # => Immutable::Hash["A" => 1, "B" => 20]

+ #

+ # @param key [Object] The key to store

+ # @param value [Object] The value to associate it with

+ # @yield [value] The previously stored value, or `nil` if none.

+ # @yieldreturn [Object] The new value to store

+ # @return [Hash]

+ def put(key, value = yield(get(key)))

+ new_trie = @trie.put(key, value)

+ if new_trie.equal?(@trie)

+ self

+ else

+ self.class.alloc(new_trie, @default)

+ end

+ end

+

+ # @private

+ # @raise NoMethodError

+ def []=(*)

+ raise NoMethodError, "Immutable::Hash doesn't support `[]='; use `put' instead"

+ end

+

+ # Return a new `Hash` with a deeply nested value modified to the result of

+ # the given code block. When traversing the nested `Hash`es and `Vector`s,

+ # non-existing keys are created with empty `Hash` values.

+ #

+ # The code block receives the existing value of the deeply nested key (or

+ # `nil` if it doesn't exist). This is useful for "transforming" the value

+ # associated with a certain key.

+ #

+ # Note that the original `Hash` and sub-`Hash`es and sub-`Vector`s are left

+ # unmodified; new data structure copies are created along the path wherever

+ # needed.

+ #

+ # @example

+ # hash = Immutable::Hash["a" => Immutable::Hash["b" => Immutable::Hash["c" => 42]]]

+ # hash.update_in("a", "b", "c") { |value| value + 5 }

+ # # => Immutable::Hash["a" => Immutable::Hash["b" => Immutable::Hash["c" => 47]]]

+ #

+ # @param key_path [::Array<Object>] List of keys which form the path to the key to be modified

+ # @yield [value] The previously stored value

+ # @yieldreturn [Object] The new value to store

+ # @return [Hash]

+ def update_in(*key_path, &block)

+ if key_path.empty?

+ raise ArgumentError, 'must have at least one key in path'

+ end

+ key = key_path[0]

+ if key_path.size == 1

+ new_value = block.call(get(key))

+ else

+ value = fetch(key, EmptyHash)

+ new_value = value.update_in(*key_path[1..-1], &block)

+ end

+ put(key, new_value)

+ end

+

+ # An alias for {#put} to match RubyHash's API. Does not support {#put}'s

+ # block form.

+ #

+ # @see #put

+ # @param key [Object] The key to store

+ # @param value [Object] The value to associate it with

+ # @return [Hash]

+ def store(key, value)

+ put(key, value)

+ end

+

+ # Return a new `Hash` with `key` removed. If `key` is not present, return

+ # `self`.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].delete("B")

+ # # => Immutable::Hash["A" => 1, "C" => 3]

+ #

+ # @param key [Object] The key to remove

+ # @return [Hash]

+ def delete(key)

+ derive_new_hash(@trie.delete(key))

+ end

+

+ # Call the block once for each key/value pair in this `Hash`, passing the key/value

+ # pair as parameters. No specific iteration order is guaranteed, though the order will

+ # be stable for any particular `Hash`.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].each { |k, v| puts "k=#{k} v=#{v}" }

+ #

+ # k=A v=1

+ # k=C v=3

+ # k=B v=2

+ # # => Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ #

+ # @yield [key, value] Once for each key/value pair.

+ # @return [self]

+ def each(&block)

+ return to_enum if not block_given?

+ @trie.each(&block)

+ self

+ end

+ alias each_pair each

+

+ # Call the block once for each key/value pair in this `Hash`, passing the key/value

+ # pair as parameters. Iteration order will be the opposite of {#each}.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].reverse_each { |k, v| puts "k=#{k} v=#{v}" }

+ #

+ # k=B v=2

+ # k=C v=3

+ # k=A v=1

+ # # => Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ #

+ # @yield [key, value] Once for each key/value pair.

+ # @return [self]

+ def reverse_each(&block)

+ return enum_for(:reverse_each) if not block_given?

+ @trie.reverse_each(&block)

+ self

+ end

+

+ # Call the block once for each key/value pair in this `Hash`, passing the key as a

+ # parameter. Ordering guarantees are the same as {#each}.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].each_key { |k| puts "k=#{k}" }

+ #

+ # k=A

+ # k=C

+ # k=B

+ # # => Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ #

+ # @yield [key] Once for each key/value pair.

+ # @return [self]

+ def each_key

+ return enum_for(:each_key) if not block_given?

+ @trie.each { |k,v| yield k }

+ self

+ end

+

+ # Call the block once for each key/value pair in this `Hash`, passing the value as a

+ # parameter. Ordering guarantees are the same as {#each}.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].each_value { |v| puts "v=#{v}" }

+ #

+ # v=1

+ # v=3

+ # v=2

+ # # => Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ #

+ # @yield [value] Once for each key/value pair.

+ # @return [self]

+ def each_value

+ return enum_for(:each_value) if not block_given?

+ @trie.each { |k,v| yield v }

+ self

+ end

+

+ # Call the block once for each key/value pair in this `Hash`, passing the key/value

+ # pair as parameters. The block should return a `[key, value]` array each time.

+ # All the returned `[key, value]` arrays will be gathered into a new `Hash`.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.map { |k, v| ["new-#{k}", v * v] }

+ # # => Hash["new-C" => 9, "new-B" => 4, "new-A" => 1]

+ #

+ # @yield [key, value] Once for each key/value pair.

+ # @return [Hash]

+ def map

+ return enum_for(:map) unless block_given?

+ return self if empty?

+ self.class.new(super, &@default)

+ end

+ alias collect map

+

+ # Return a new `Hash` with all the key/value pairs for which the block returns true.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.select { |k, v| v >= 2 }

+ # # => Immutable::Hash["B" => 2, "C" => 3]

+ #

+ # @yield [key, value] Once for each key/value pair.

+ # @yieldreturn Truthy if this pair should be present in the new `Hash`.

+ # @return [Hash]

+ def select(&block)

+ return enum_for(:select) unless block_given?

+ derive_new_hash(@trie.select(&block))

+ end

+ alias find_all select

+ alias keep_if select

+

+ # Yield `[key, value]` pairs until one is found for which the block returns true.

+ # Return that `[key, value]` pair. If the block never returns true, return `nil`.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.find { |k, v| v.even? }

+ # # => ["B", 2]

+ #

+ # @return [Array]

+ # @yield [key, value] At most once for each key/value pair, until the block returns `true`.

+ # @yieldreturn Truthy to halt iteration and return the yielded key/value pair.

+ def find

+ return enum_for(:find) unless block_given?

+ each { |entry| return entry if yield entry }

+ nil

+ end

+ alias detect find

+

+ # Return a new `Hash` containing all the key/value pairs from this `Hash` and

+ # `other`. If no block is provided, the value for entries with colliding keys

+ # will be that from `other`. Otherwise, the value for each duplicate key is

+ # determined by calling the block.

+ #

+ # `other` can be an `Immutable::Hash`, a built-in Ruby `Hash`, or any `Enumerable`

+ # object which yields `[key, value]` pairs.

+ #

+ # @example

+ # h1 = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h2 = Immutable::Hash["C" => 70, "D" => 80]

+ # h1.merge(h2)

+ # # => Immutable::Hash["C" => 70, "A" => 1, "D" => 80, "B" => 2]

+ # h1.merge(h2) { |key, v1, v2| v1 + v2 }

+ # # => Immutable::Hash["C" => 73, "A" => 1, "D" => 80, "B" => 2]

+ #

+ # @param other [::Enumerable] The collection to merge with

+ # @yieldparam key [Object] The key which was present in both collections

+ # @yieldparam my_value [Object] The associated value from this `Hash`

+ # @yieldparam other_value [Object] The associated value from the other collection

+ # @yieldreturn [Object] The value to associate this key with in the new `Hash`

+ # @return [Hash]

+ def merge(other)

+ trie = if block_given?

+ other.reduce(@trie) do |trie, (key, value)|

+ if (entry = trie.get(key))

+ trie.put(key, yield(key, entry[1], value))

+ else

+ trie.put(key, value)

+ end

+ end

+ else

+ @trie.bulk_put(other)

+ end

+

+ derive_new_hash(trie)

+ end

+

+ # Retrieve the value corresponding to the given key object, or use the provided

+ # default value or block, or otherwise raise a `KeyError`.

+ #

+ # @overload fetch(key)

+ # Retrieve the value corresponding to the given key, or raise a `KeyError`

+ # if it is not found.

+ # @param key [Object] The key to look up

+ # @overload fetch(key) { |key| ... }

+

+ # Return a sorted {Vector} which contains all the `[key, value]` pairs in

+ # this `Hash` as two-element `Array`s.

+ #

+ # @overload sort

+ # Uses `#<=>` to determine sorted order.

+ # @overload sort { |(k1, v1), (k2, v2)| ... }

+ # Uses the block as a comparator to determine sorted order.

+ #

+ # @example

+ # h = Immutable::Hash["Dog" => 1, "Elephant" => 2, "Lion" => 3]

+ # h.sort { |(k1, v1), (k2, v2)| k1.size <=> k2.size }

+ # # => Immutable::Vector[["Dog", 1], ["Lion", 3], ["Elephant", 2]]

+ # @yield [(k1, v1), (k2, v2)] Any number of times with different pairs of key/value associations.

+ # @yieldreturn [Integer] Negative if the first pair should be sorted

+ # lower, positive if the latter pair, or 0 if equal.

+ #

+ # @see ::Enumerable#sort

+ #

+ # @return [Vector]

+ def sort

+ Vector.new(super)

+ end

+

+ # Return a {Vector} which contains all the `[key, value]` pairs in this `Hash`

+ # as two-element Arrays. The order which the pairs will appear in is determined by

+ # passing each pair to the code block to obtain a sort key object, and comparing

+ # the sort keys using `#<=>`.

+ #

+ # @see ::Enumerable#sort_by

+ #

+ # @example

+ # h = Immutable::Hash["Dog" => 1, "Elephant" => 2, "Lion" => 3]

+ # h.sort_by { |key, value| key.size }

+ # # => Immutable::Vector[["Dog", 1], ["Lion", 3], ["Elephant", 2]]

+ #

+ # @yield [key, value] Once for each key/value pair.

+ # @yieldreturn a sort key object for the yielded pair.

+ # @return [Vector]

+ def sort_by

+ Vector.new(super)

+ end

+

+ # Return a new `Hash` with the associations for all of the given `keys` removed.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.except("A", "C") # => Immutable::Hash["B" => 2]

+ #

+ # @param keys [Array] The keys to remove

+ # @return [Hash]

+ def except(*keys)

+ keys.reduce(self) { |hash, key| hash.delete(key) }

+ end

+

+ # Return a new `Hash` with only the associations for the `wanted` keys retained.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.slice("B", "C") # => Immutable::Hash["B" => 2, "C" => 3]

+ #

+ # @param wanted [::Enumerable] The keys to retain

+ # @return [Hash]

+ def slice(*wanted)

+ trie = Trie.new(0)

+ wanted.each { |key| trie.put!(key, get(key)) if key?(key) }

+ self.class.alloc(trie, @default)

+ end

+

+ # Return a {Vector} of the values which correspond to the `wanted` keys.

+ # If any of the `wanted` keys are not present in this `Hash`, `nil` will be

+ # placed instead, or the result of the default proc (if one is defined),

+ # similar to the behavior of {#get}.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.values_at("B", "A", "D") # => Immutable::Vector[2, 1, nil]

+ #

+ # @param wanted [Array] The keys to retrieve

+ # @return [Vector]

+ def values_at(*wanted)

+ Vector.new(wanted.map { |key| get(key) }.freeze)

+ end

+

+ # Return a {Vector} of the values which correspond to the `wanted` keys.

+ # If any of the `wanted` keys are not present in this `Hash`, raise `KeyError`

+ # exception.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.fetch_values("C", "A") # => Immutable::Vector[3, 1]

+ # h.fetch_values("C", "Z") # => KeyError: key not found: "Z"

+ #

+ # @param wanted [Array] The keys to retrieve

+ # @return [Vector]

+ def fetch_values(*wanted)

+ array = wanted.map { |key| fetch(key) }

+ Vector.new(array.freeze)

+ end

+

+ # Return the value of successively indexing into a nested collection.

+ # If any of the keys is not present, return `nil`.

+ #

+ # @example

+ # h = Immutable::Hash[a: 9, b: Immutable::Hash[c: 'a', d: 4], e: nil]

+ # h.dig(:b, :c) # => "a"

+ # h.dig(:b, :f) # => nil

+ #

+ # @return [Object]

+ def dig(key, *rest)

+ value = self[key]

+ if rest.empty? || value.nil?

+ value

+ else

+ value.dig(*rest)

+ end

+ end

+

+ # Return a new {Set} containing the keys from this `Hash`.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3, "D" => 2].keys

+ # # => Immutable::Set["D", "C", "B", "A"]

+ #

+ # @return [Set]

+ def keys

+ Set.alloc(@trie)

+ end

+

+ # Return a new {Vector} populated with the values from this `Hash`.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3, "D" => 2].values

+ # # => Immutable::Vector[2, 3, 2, 1]

+ #

+ # @return [Vector]

+ def values

+ Vector.new(each_value.to_a.freeze)

+ end

+

+ # Return a new `Hash` created by using keys as values and values as keys.

+ # If there are multiple values which are equivalent (as determined by `#hash` and

+ # `#eql?`), only one out of each group of equivalent values will be

+ # retained. Which one specifically is undefined.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3, "D" => 2].invert

+ # # => Immutable::Hash[1 => "A", 3 => "C", 2 => "B"]

+ #

+ # @return [Hash]

+ def invert

+ pairs = []

+ each { |k,v| pairs << [v, k] }

+ self.class.new(pairs, &@default)

+ end

+

+ # Return a new {Vector} which is a one-dimensional flattening of this `Hash`.

+ # If `level` is 1, all the `[key, value]` pairs in the hash will be concatenated

+ # into one {Vector}. If `level` is greater than 1, keys or values which are

+ # themselves `Array`s or {Vector}s will be recursively flattened into the output

+ # {Vector}. The depth to which that flattening will be recursively applied is

+ # determined by `level`.

+ #

+ # As a special case, if `level` is 0, each `[key, value]` pair will be a

+ # separate element in the returned {Vector}.

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => [2, 3, 4]]

+ # h.flatten

+ # # => Immutable::Vector["A", 1, "B", [2, 3, 4]]

+ # h.flatten(2)

+ # # => Immutable::Vector["A", 1, "B", 2, 3, 4]

+ #

+ # @param level [Integer] The number of times to recursively flatten the `[key, value]` pairs in this `Hash`.

+ # @return [Vector]

+ def flatten(level = 1)

+ return Vector.new(self) if level == 0

+ array = []

+ each { |k,v| array << k; array << v }

+ array.flatten!(level-1) if level > 1

+ Vector.new(array.freeze)

+ end

+

+ # Searches through the `Hash`, comparing `obj` with each key (using `#==`).

+ # When a matching key is found, return the `[key, value]` pair as an array.

+ # Return `nil` if no match is found.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].assoc("B") # => ["B", 2]

+ #

+ # @param obj [Object] The key to search for (using #==)

+ # @return [Array]

+ def assoc(obj)

+ each { |entry| return entry if obj == entry[0] }

+ nil

+ end

+

+ # Searches through the `Hash`, comparing `obj` with each value (using `#==`).

+ # When a matching value is found, return the `[key, value]` pair as an array.

+ # Return `nil` if no match is found.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].rassoc(2) # => ["B", 2]

+ #

+ # @param obj [Object] The value to search for (using #==)

+ # @return [Array]

+ def rassoc(obj)

+ each { |entry| return entry if obj == entry[1] }

+ nil

+ end

+

+ # Searches through the `Hash`, comparing `value` with each value (using `#==`).

+ # When a matching value is found, return its associated key object.

+ # Return `nil` if no match is found.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].key(2) # => "B"

+ #

+ # @param value [Object] The value to search for (using #==)

+ # @return [Object]

+ def key(value)

+ each { |entry| return entry[0] if value == entry[1] }

+ nil

+ end

+

+ # Return a randomly chosen `[key, value]` pair from this `Hash`. If the hash is empty,

+ # return `nil`.

+ #

+ # @example

+ # Immutable::Hash["A" => 1, "B" => 2, "C" => 3].sample

+ # # => ["C", 3]

+ #

+ # @return [Array]

+ def sample

+ @trie.at(rand(size))

+ end

+

+ # Return an empty `Hash` instance, of the same class as this one. Useful if you

+ # have multiple subclasses of `Hash` and want to treat them polymorphically.

+ # Maintains the default block, if there is one.

+ #

+ # @return [Hash]

+ def clear

+ if @default

+ self.class.alloc(EmptyTrie, @default)

+ else

+ self.class.empty

+ end

+ end

+

+ # Return true if `other` has the same type and contents as this `Hash`.

+ #

+ # @param other [Object] The collection to compare with

+ # @return [Boolean]

+ def eql?(other)

+ return true if other.equal?(self)

+ instance_of?(other.class) && @trie.eql?(other.instance_variable_get(:@trie))

+ end

+

+ # Return true if `other` has the same contents as this `Hash`. Will convert

+ # `other` to a Ruby `Hash` using `#to_hash` if necessary.

+ #

+ # @param other [Object] The object to compare with

+ # @return [Boolean]

+ def ==(other)

+ eql?(other) || (other.respond_to?(:to_hash) && to_hash == other.to_hash)

+ end

+

+ # Return true if this `Hash` is a proper superset of `other`, which means

+ # all `other`'s keys are contained in this `Hash` with identical

+ # values, and the two hashes are not identical.

+ #

+ # @param other [Immutable::Hash] The object to compare with

+ # @return [Boolean]

+ def >(other)

+ self != other && self >= other

+ end

+

+ # Return true if this `Hash` is a superset of `other`, which means all

+ # `other`'s keys are contained in this `Hash` with identical values.

+ #

+ # @param other [Immutable::Hash] The object to compare with

+ # @return [Boolean]

+ def >=(other)

+ other.each do |key, value|

+ if self[key] != value

+ return false

+ end

+ end

+ true

+ end

+

+ # Return true if this `Hash` is a proper subset of `other`, which means all

+ # its keys are contained in `other` with the identical values, and the two

+ # hashes are not identical.

+ #

+ # @param other [Immutable::Hash] The object to compare with

+ # @return [Boolean]

+ def <(other)

+ other > self

+ end

+

+ # Return true if this `Hash` is a subset of `other`, which means all its

+ # keys are contained in `other` with the identical values, and the two

+ # hashes are not identical.

+ #

+ # @param other [Immutable::Hash] The object to compare with

+ # @return [Boolean]

+ def <=(other)

+ other >= self

+ end

+

+ # See `Object#hash`.

+ # @return [Integer]

+ def hash

+ keys.to_a.sort.reduce(0) do |hash, key|

+ (hash << 32) - hash + key.hash + get(key).hash

+ end

+ end

+

+ # Return the contents of this `Hash` as a programmer-readable `String`. If all the

+ # keys and values are serializable as Ruby literal strings, the returned string can

+ # be passed to `eval` to reconstitute an equivalent `Hash`. The default

+ # block (if there is one) will be lost when doing this, however.

+ #

+ # @return [String]

+ def inspect

+ result = "#{self.class}["

+ i = 0

+ each do |key, val|

+ result << ', ' if i > 0

+ result << key.inspect << ' => ' << val.inspect

+ i += 1

+ end

+ result << ']'

+ end

+

+ # Return `self`. Since this is an immutable object duplicates are

+ # equivalent.

+ # @return [Hash]

+ def dup

+ self

+ end

+ alias clone dup

+

+ # Allows this `Hash` to be printed at the `pry` console, or using `pp` (from the

+ # Ruby standard library), in a way which takes the amount of horizontal space on

+ # the screen into account, and which indents nested structures to make them easier

+ # to read.

+ #

+ # @private

+ def pretty_print(pp)

+ pp.group(1, "#{self.class}[", ']') do

+ pp.breakable ''

+ pp.seplist(self, nil) do |key, val|

+ pp.group do

+ key.pretty_print(pp)

+ pp.text ' => '

+ pp.group(1) do

+ pp.breakable ''

+ val.pretty_print(pp)

+ end

+ end

+ end

+ end

+ end

+

+ # Convert this `Immutable::Hash` to an instance of Ruby's built-in `Hash`.

+ #

+ # @return [::Hash]

+ def to_hash

+ output = {}

+ each do |key, value|

+ output[key] = value

+ end

+ output

+ end

+ alias to_h to_hash

+

+ # Return a `Proc` which accepts a key as an argument and returns the value.

+ # The `Proc` behaves like {#get} (when the key is missing, it returns nil or

+ # the result of the default proc).

+ #

+ # @example

+ # h = Immutable::Hash["A" => 1, "B" => 2, "C" => 3]

+ # h.to_proc.call("B")

+ # # => 2

+ # ["A", "C", "X"].map(&h) # The & is short for .to_proc in Ruby

+ # # => [1, 3, nil]

+ #

+ # @return [Proc]

+ def to_proc

+ lambda { |key| get(key) }

+ end

+

+ # @return [::Hash]

+ # @private

+ def marshal_dump

+ to_hash

+ end

+

+ # @private

+ def marshal_load(dictionary)

+ @trie = Trie[dictionary]

+ end

+

+ private

+

+ # Return a new `Hash` which is derived from this one, using a modified {Trie}.

+ # The new `Hash` will retain the existing default block, if there is one.

+ #

+ def derive_new_hash(trie)

+ if trie.equal?(@trie)

+ self

+ elsif trie.empty?

+ if @default

+ self.class.alloc(EmptyTrie, @default)

+ else

+ self.class.empty

+ end

+ else

+ self.class.alloc(trie, @default)

+ end

+ end

+ end

+

+ # The canonical empty `Hash`. Returned by `Hash[]` when

+ # invoked with no arguments; also returned by `Hash.empty`. Prefer using this

+ # one rather than creating many empty hashes using `Hash.new`.

+ #

+ # @private

+ EmptyHash = Immutable::Hash.empty

+

+

+ # A `Vector` is an ordered, integer-indexed collection of objects. Like

+ # Ruby's `Array`, `Vector` indexing starts at zero and negative indexes count

+ # back from the end.

+ #

+ # `Vector` has a similar interface to `Array`. The main difference is methods

+ # that would destructively update an `Array` (such as {#insert} or

+ # {#delete_at}) instead return new `Vectors` and leave the existing one

+ # unchanged.

+ #

+ # ### Creating New Vectors

+ #

+ # Immutable::Vector.new([:first, :second, :third])

+ # Immutable::Vector[1, 2, 3, 4, 5]

+ #

+ # ### Retrieving Items from Vectors

+ #

+ # vector = Immutable::Vector[1, 2, 3, 4, 5]

+ #

+ # vector[0] # => 1

+ # vector[-1] # => 5

+ # vector[0,3] # => Immutable::Vector[1, 2, 3]

+ # vector[1..-1] # => Immutable::Vector[2, 3, 4, 5]

+ # vector.first # => 1

+ # vector.last # => 5

+ #

+ # ### Creating Modified Vectors

+ #

+ # vector.add(6) # => Immutable::Vector[1, 2, 3, 4, 5, 6]

+ # vector.insert(1, :a, :b) # => Immutable::Vector[1, :a, :b, 2, 3, 4, 5]

+ # vector.delete_at(2) # => Immutable::Vector[1, 2, 4, 5]

+ # vector + [6, 7] # => Immutable::Vector[1, 2, 3, 4, 5, 6, 7]

+ #

+ class Vector

+ include Immutable::Enumerable

+

+ # @private

+ BLOCK_SIZE = 32

+ # @private

+ INDEX_MASK = BLOCK_SIZE - 1

+ # @private

+ BITS_PER_LEVEL = 5

+

+ # Return the number of items in this `Vector`

+ # @return [Integer]

+ attr_reader :size

+ alias length size

+

+ class << self

+ # Create a new `Vector` populated with the given items.

+ # @return [Vector]

+ def [](*items)

+ new(items.freeze)

+ end

+

+ # Return an empty `Vector`. If used on a subclass, returns an empty instance

+ # of that class.

+ #

+ # @return [Vector]

+ def empty

+ @empty ||= new

+ end

+

+ # "Raw" allocation of a new `Vector`. Used internally to create a new

+ # instance quickly after building a modified trie.

+ #

+ # @return [Vector]

+ # @private

+ def alloc(root, size, levels)

+ obj = allocate

+ obj.instance_variable_set(:@root, root)

+ obj.instance_variable_set(:@size, size)

+ obj.instance_variable_set(:@levels, levels)

+ obj.freeze

+ end

+ end

+

+ def initialize(items=[].freeze)

+ items = items.to_a

+ if items.size <= 32

+ items = items.dup.freeze if !items.frozen?

+ @root, @size, @levels = items, items.size, 0

+ else

+ root, size, levels = items, items.size, 0

+ while root.size > 32

+ root = root.each_slice(32).to_a

+ levels += 1

+ end

+ @root, @size, @levels = root.freeze, size, levels

+ end

+ freeze

+ end

+

+ # Return `true` if this `Vector` contains no items.

+ #

+ # @return [Boolean]

+ def empty?

+ @size == 0

+ end

+

+ # Return the first item in the `Vector`. If the vector is empty, return `nil`.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"].first # => "A"

+ #

+ # @return [Object]

+ def first

+ get(0)

+ end

+

+ # Return the last item in the `Vector`. If the vector is empty, return `nil`.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"].last # => "C"

+ #

+ # @return [Object]

+ def last

+ get(-1)

+ end

+

+ # Return a new `Vector` with `item` added after the last occupied position.

+ #

+ # @example

+ # Immutable::Vector[1, 2].add(99) # => Immutable::Vector[1, 2, 99]

+ #

+ # @param item [Object] The object to insert at the end of the vector

+ # @return [Vector]

+ def add(item)

+ update_root(@size, item)

+ end

+ alias << add

+ alias push add

+

+ # Return a new `Vector` with a new value at the given `index`. If `index`

+ # is greater than the length of the vector, the returned vector will be

+ # padded with `nil`s to the correct size.

+ #

+ # @overload set(index, item)

+ # Return a new `Vector` with the item at `index` replaced by `item`.

+ #

+ # @param item [Object] The object to insert into that position

+ # @example

+ # Immutable::Vector[1, 2, 3, 4].set(2, 99)

+ # # => Immutable::Vector[1, 2, 99, 4]

+ # Immutable::Vector[1, 2, 3, 4].set(-1, 99)

+ # # => Immutable::Vector[1, 2, 3, 99]

+ # Immutable::Vector[].set(2, 99)

+ # # => Immutable::Vector[nil, nil, 99]

+ #

+ # @overload set(index)

+ # Return a new `Vector` with the item at `index` replaced by the return

+ # value of the block.

+ #

+ # @yield (existing) Once with the existing value at the given `index`.

+ # @example

+ # Immutable::Vector[1, 2, 3, 4].set(2) { |v| v * 10 }

+ # # => Immutable::Vector[1, 2, 30, 4]

+ #

+ # @param index [Integer] The index to update. May be negative.

+ # @return [Vector]

+ def set(index, item = yield(get(index)))

+ raise IndexError, "index #{index} outside of vector bounds" if index < -@size

+ index += @size if index < 0

+ if index > @size

+ suffix = Array.new(index - @size, nil)

+ suffix << item

+ replace_suffix(@size, suffix)

+ else

+ update_root(index, item)

+ end

+ end

+

+ # Return a new `Vector` with a deeply nested value modified to the result

+ # of the given code block. When traversing the nested `Vector`s and

+ # `Hash`es, non-existing keys are created with empty `Hash` values.

+ #

+ # The code block receives the existing value of the deeply nested key (or

+ # `nil` if it doesn't exist). This is useful for "transforming" the value

+ # associated with a certain key.

+ #

+ # Note that the original `Vector` and sub-`Vector`s and sub-`Hash`es are

+ # left unmodified; new data structure copies are created along the path

+ # wherever needed.

+ #

+ # @example

+ # v = Immutable::Vector[123, 456, 789, Immutable::Hash["a" => Immutable::Vector[5, 6, 7]]]

+ # v.update_in(3, "a", 1) { |value| value + 9 }

+ # # => Immutable::Vector[123, 456, 789, Immutable::Hash["a" => Immutable::Vector[5, 15, 7]]]

+ #

+ # @param key_path [Object(s)] List of keys which form the path to the key to be modified

+ # @yield [value] The previously stored value

+ # @yieldreturn [Object] The new value to store

+ # @return [Vector]

+ def update_in(*key_path, &block)

+ if key_path.empty?

+ raise ArgumentError, 'must have at least one key in path'

+ end

+ key = key_path[0]

+ if key_path.size == 1

+ new_value = block.call(get(key))

+ else

+ value = fetch(key, Immutable::EmptyHash)

+ new_value = value.update_in(*key_path[1..-1], &block)

+ end

+ set(key, new_value)

+ end

+

+ # Retrieve the item at `index`. If there is none (either the provided index

+ # is too high or too low), return `nil`.

+ #

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D"]

+ # v.get(2) # => "C"

+ # v.get(-1) # => "D"

+ # v.get(4) # => nil

+ #

+ # @param index [Integer] The index to retrieve

+ # @return [Object]

+ def get(index)

+ return nil if @size == 0

+ index += @size if index < 0

+ return nil if index >= @size || index < 0

+ leaf_node_for(@root, @levels * BITS_PER_LEVEL, index)[index & INDEX_MASK]

+ end

+ alias at get

+

+ # Retrieve the value at `index` with optional default.

+ #

+ # @overload fetch(index)

+ # Retrieve the value at the given index, or raise an `IndexError` if not

+ # found.

+ #

+ # @param index [Integer] The index to look up

+ # @raise [IndexError] if index does not exist

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D"]

+ # v.fetch(2) # => "C"

+ # v.fetch(-1) # => "D"

+ # v.fetch(4) # => IndexError: index 4 outside of vector bounds

+ #

+ # @overload fetch(index) { |index| ... }

+ # Retrieve the value at the given index, or return the result of yielding

+ # the block if not found.

+ #

+ # @yield Once if the index is not found.

+ # @yieldparam [Integer] index The index which does not exist

+ # @yieldreturn [Object] Default value to return

+ # @param index [Integer] The index to look up

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D"]

+ # v.fetch(2) { |i| i * i } # => "C"

+ # v.fetch(4) { |i| i * i } # => 16

+ #

+ # @overload fetch(index, default)

+ # Retrieve the value at the given index, or return the provided `default`

+ # value if not found.

+ #

+ # @param index [Integer] The index to look up

+ # @param default [Object] Object to return if the key is not found

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D"]

+ # v.fetch(2, "Z") # => "C"

+ # v.fetch(4, "Z") # => "Z"

+ #

+ # @return [Object]

+ def fetch(index, default = (missing_default = true))

+ if index >= -@size && index < @size

+ get(index)

+ elsif block_given?

+ yield(index)

+ elsif !missing_default

+ default

+ else

+ raise IndexError, "index #{index} outside of vector bounds"

+ end

+ end

+

+ # Return the value of successively indexing into a nested collection.

+ # If any of the keys is not present, return `nil`.

+ #

+ # @example

+ # v = Immutable::Vector[9, Immutable::Hash[c: 'a', d: 4]]

+ # v.dig(1, :c) # => "a"

+ # v.dig(1, :f) # => nil

+ #

+ # @return [Object]

+ def dig(key, *rest)

+ value = self[key]

+ if rest.empty? || value.nil?

+ value

+ else

+ value.dig(*rest)

+ end

+ end

+

+ # Return specific objects from the `Vector`. All overloads return `nil` if

+ # the starting index is out of range.

+ #

+ # @overload vector.slice(index)

+ # Returns a single object at the given `index`. If `index` is negative,

+ # count backwards from the end.

+ #

+ # @param index [Integer] The index to retrieve. May be negative.

+ # @return [Object]

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D", "E", "F"]

+ # v[2] # => "C"

+ # v[-1] # => "F"

+ # v[6] # => nil

+ #

+ # @overload vector.slice(index, length)

+ # Return a subvector starting at `index` and continuing for `length`

+ # elements or until the end of the `Vector`, whichever occurs first.

+ #

+ # @param start [Integer] The index to start retrieving items from. May be

+ # negative.

+ # @param length [Integer] The number of items to retrieve.

+ # @return [Vector]

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D", "E", "F"]

+ # v[2, 3] # => Immutable::Vector["C", "D", "E"]

+ # v[-2, 3] # => Immutable::Vector["E", "F"]

+ # v[20, 1] # => nil

+ #

+ # @overload vector.slice(index..end)

+ # Return a subvector starting at `index` and continuing to index

+ # `end` or the end of the `Vector`, whichever occurs first.

+ #

+ # @param range [Range] The range of indices to retrieve.

+ # @return [Vector]

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D", "E", "F"]

+ # v[2..3] # => Immutable::Vector["C", "D"]

+ # v[-2..100] # => Immutable::Vector["E", "F"]

+ # v[20..21] # => nil

+ def slice(arg, length = (missing_length = true))

+ if missing_length

+ if arg.is_a?(Range)

+ from, to = arg.begin, arg.end

+ from += @size if from < 0

+ to += @size if to < 0

+ to += 1 if !arg.exclude_end?

+ length = to - from

+ length = 0 if length < 0

+ subsequence(from, length)

+ else

+ get(arg)

+ end

+ else

+ arg += @size if arg < 0

+ subsequence(arg, length)

+ end

+ end

+ alias [] slice

+

+ # Return a new `Vector` with the given values inserted before the element

+ # at `index`. If `index` is greater than the current length, `nil` values

+ # are added to pad the `Vector` to the required size.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C", "D"].insert(2, "X", "Y", "Z")

+ # # => Immutable::Vector["A", "B", "X", "Y", "Z", "C", "D"]

+ # Immutable::Vector[].insert(2, "X", "Y", "Z")

+ # # => Immutable::Vector[nil, nil, "X", "Y", "Z"]

+ #

+ # @param index [Integer] The index where the new items should go

+ # @param items [Array] The items to add

+ # @return [Vector]

+ # @raise [IndexError] if index exceeds negative range.

+ def insert(index, *items)

+ raise IndexError if index < -@size

+ index += @size if index < 0

+

+ if index < @size

+ suffix = flatten_suffix(@root, @levels * BITS_PER_LEVEL, index, [])

+ suffix.unshift(*items)

+ elsif index == @size

+ suffix = items

+ else

+ suffix = Array.new(index - @size, nil).concat(items)

+ index = @size

+ end

+

+ replace_suffix(index, suffix)

+ end

+

+ # Return a new `Vector` with the element at `index` removed. If the given `index`

+ # does not exist, return `self`.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C", "D"].delete_at(2)

+ # # => Immutable::Vector["A", "B", "D"]

+ #

+ # @param index [Integer] The index to remove

+ # @return [Vector]

+ def delete_at(index)

+ return self if index >= @size || index < -@size

+ index += @size if index < 0

+

+ suffix = flatten_suffix(@root, @levels * BITS_PER_LEVEL, index, [])

+ replace_suffix(index, suffix.tap(&:shift))

+ end

+

+ # Return a new `Vector` with the last element removed. Return `self` if

+ # empty.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"].pop # => Immutable::Vector["A", "B"]

+ #

+ # @return [Vector]

+ def pop

+ return self if @size == 0

+ replace_suffix(@size-1, [])

+ end

+

+ # Return a new `Vector` with `object` inserted before the first element,

+ # moving the other elements upwards.

+ #

+ # @example

+ # Immutable::Vector["A", "B"].unshift("Z")

+ # # => Immutable::Vector["Z", "A", "B"]

+ #

+ # @param object [Object] The value to prepend

+ # @return [Vector]

+ def unshift(object)

+ insert(0, object)

+ end

+

+ # Return a new `Vector` with the first element removed. If empty, return

+ # `self`.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"].shift # => Immutable::Vector["B", "C"]

+ #

+ # @return [Vector]

+ def shift

+ delete_at(0)

+ end

+

+ # Call the given block once for each item in the vector, passing each

+ # item from first to last successively to the block. If no block is given,

+ # an `Enumerator` is returned instead.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"].each { |e| puts "Element: #{e}" }

+ #

+ # Element: A

+ # Element: B

+ # Element: C

+ # # => Immutable::Vector["A", "B", "C"]

+ #

+ # @return [self, Enumerator]

+ def each(&block)

+ return to_enum unless block_given?

+ traverse_depth_first(@root, @levels, &block)

+ self

+ end

+

+ # Call the given block once for each item in the vector, from last to

+ # first.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"].reverse_each { |e| puts "Element: #{e}" }

+ #

+ # Element: C

+ # Element: B

+ # Element: A

+ #

+ # @return [self]

+ def reverse_each(&block)

+ return enum_for(:reverse_each) unless block_given?

+ reverse_traverse_depth_first(@root, @levels, &block)

+ self

+ end

+

+ # Return a new `Vector` containing all elements for which the given block returns

+ # true.

+ #

+ # @example

+ # Immutable::Vector["Bird", "Cow", "Elephant"].select { |e| e.size >= 4 }

+ # # => Immutable::Vector["Bird", "Elephant"]

+ #

+ # @return [Vector]

+ # @yield [element] Once for each element.

+ def select

+ return enum_for(:select) unless block_given?

+ reduce(self.class.empty) { |vector, item| yield(item) ? vector.add(item) : vector }

+ end

+ alias find_all select

+ alias keep_if select

+

+ # Return a new `Vector` with all items which are equal to `obj` removed.

+ # `#==` is used for checking equality.

+ #

+ # @example

+ # Immutable::Vector["C", "B", "A", "B"].delete("B") # => Immutable::Vector["C", "A"]

+ #

+ # @param obj [Object] The object to remove (every occurrence)

+ # @return [Vector]

+ def delete(obj)

+ select { |item| item != obj }

+ end

+

+ # Invoke the given block once for each item in the vector, and return a new

+ # `Vector` containing the values returned by the block. If no block is

+ # provided, return an enumerator.

+ #

+ # @example

+ # Immutable::Vector[3, 2, 1].map { |e| e * e } # => Immutable::Vector[9, 4, 1]

+ #

+ # @return [Vector, Enumerator]

+ def map

+ return enum_for(:map) if not block_given?

+ return self if empty?

+ self.class.new(super)

+ end

+ alias collect map

+

+ # Return a new `Vector` with the concatenated results of running the block once

+ # for every element in this `Vector`.

+ #

+ # @example

+ # Immutable::Vector[1, 2, 3].flat_map { |x| [x, -x] }

+ # # => Immutable::Vector[1, -1, 2, -2, 3, -3]

+ #

+ # @return [Vector]

+ def flat_map

+ return enum_for(:flat_map) if not block_given?

+ return self if empty?

+ self.class.new(super)

+ end

+

+ # Return a new `Vector` with the same elements as this one, but randomly permuted.

+ #

+ # @example

+ # Immutable::Vector[1, 2, 3, 4].shuffle # => Immutable::Vector[4, 1, 3, 2]

+ #

+ # @return [Vector]

+ def shuffle

+ self.class.new(((array = to_a).frozen? ? array.shuffle : array.shuffle!).freeze)

+ end

+

+ # Return a new `Vector` with no duplicate elements, as determined by `#hash` and

+ # `#eql?`. For each group of equivalent elements, only the first will be retained.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C", "B"].uniq # => Immutable::Vector["A", "B", "C"]

+ # Immutable::Vector["a", "A", "b"].uniq(&:upcase) # => Immutable::Vector["a", "b"]

+ #

+ # @return [Vector]

+ def uniq(&block)

+ array = to_a

+ if array.frozen?

+ self.class.new(array.uniq(&block).freeze)

+ elsif array.uniq!(&block) # returns nil if no changes were made

+ self.class.new(array.freeze)

+ else

+ self

+ end

+ end

+

+ # Return a new `Vector` with the same elements as this one, but in reverse order.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"].reverse # => Immutable::Vector["C", "B", "A"]

+ #

+ # @return [Vector]

+ def reverse

+ self.class.new(((array = to_a).frozen? ? array.reverse : array.reverse!).freeze)

+ end

+

+ # Return a new `Vector` with the same elements, but rotated so that the one at

+ # index `count` is the first element of the new vector. If `count` is positive,

+ # the elements will be shifted left, and those shifted past the lowest position

+ # will be moved to the end. If `count` is negative, the elements will be shifted

+ # right, and those shifted past the last position will be moved to the beginning.

+ #

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D", "E", "F"]

+ # v.rotate(2) # => Immutable::Vector["C", "D", "E", "F", "A", "B"]

+ # v.rotate(-1) # => Immutable::Vector["F", "A", "B", "C", "D", "E"]

+ #

+ # @param count [Integer] The number of positions to shift items by

+ # @return [Vector]

+ def rotate(count = 1)

+ return self if (count % @size) == 0

+ self.class.new(((array = to_a).frozen? ? array.rotate(count) : array.rotate!(count)).freeze)

+ end

+

+ # Return a new `Vector` with all nested vectors and arrays recursively "flattened

+ # out". That is, their elements inserted into the new `Vector` in the place where

+ # the nested array/vector originally was. If an optional `level` argument is

+ # provided, the flattening will only be done recursively that number of times.

+ # A `level` of 0 means not to flatten at all, 1 means to only flatten nested

+ # arrays/vectors which are directly contained within this `Vector`.

+ #

+ # @example

+ # v = Immutable::Vector["A", Immutable::Vector["B", "C", Immutable::Vector["D"]]]

+ # v.flatten(1)

+ # # => Immutable::Vector["A", "B", "C", Immutable::Vector["D"]]

+ # v.flatten

+ # # => Immutable::Vector["A", "B", "C", "D"]

+ #

+ # @param level [Integer] The depth to which flattening should be applied

+ # @return [Vector]

+ def flatten(level = -1)

+ return self if level == 0

+ array = to_a

+ if array.frozen?

+ self.class.new(array.flatten(level).freeze)

+ elsif array.flatten!(level) # returns nil if no changes were made

+ self.class.new(array.freeze)

+ else

+ self

+ end

+ end

+

+ # Return a new `Vector` built by concatenating this one with `other`. `other`

+ # can be any object which is convertible to an `Array` using `#to_a`.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C"] + ["D", "E"]

+ # # => Immutable::Vector["A", "B", "C", "D", "E"]

+ #

+ # @param other [Enumerable] The collection to concatenate onto this vector

+ # @return [Vector]

+ def +(other)

+ other = other.to_a

+ other = other.dup if other.frozen?

+ replace_suffix(@size, other)

+ end

+ alias concat +

+

+ # Combine two vectors by "zipping" them together. `others` should be arrays

+ # and/or vectors. The corresponding elements from this `Vector` and each of

+ # `others` (that is, the elements with the same indices) will be gathered

+ # into arrays.

+ #

+ # If `others` contains fewer elements than this vector, `nil` will be used

+ # for padding.

+ #

+ # @overload zip(*others)

+ # Return a new vector containing the new arrays.

+ #

+ # @return [Vector]

+ #

+ # @overload zip(*others)

+ # @yield [pair] once for each array

+ # @return [nil]

+ #

+ # @example

+ # v1 = Immutable::Vector["A", "B", "C"]

+ # v2 = Immutable::Vector[1, 2]

+ # v1.zip(v2)

+ # # => Immutable::Vector[["A", 1], ["B", 2], ["C", nil]]

+ #

+ # @param others [Array] The arrays/vectors to zip together with this one

+ # @return [Vector]

+ def zip(*others)

+ if block_given?

+ super

+ else

+ self.class.new(super)

+ end

+ end

+

+ # Return a new `Vector` with the same items, but sorted.

+ #

+ # @overload sort

+ # Compare elements with their natural sort key (`#<=>`).

+ #

+ # @example

+ # Immutable::Vector["Elephant", "Dog", "Lion"].sort

+ # # => Immutable::Vector["Dog", "Elephant", "Lion"]

+ #

+ # @overload sort

+ # Uses the block as a comparator to determine sorted order.

+ #

+ # @yield [a, b] Any number of times with different pairs of elements.

+ # @yieldreturn [Integer] Negative if the first element should be sorted

+ # lower, positive if the latter element, or 0 if

+ # equal.

+ # @example

+ # Immutable::Vector["Elephant", "Dog", "Lion"].sort { |a,b| a.size <=> b.size }

+ # # => Immutable::Vector["Dog", "Lion", "Elephant"]

+ #

+ # @return [Vector]

+ def sort

+ self.class.new(super)

+ end

+

+ # Return a new `Vector` with the same items, but sorted. The sort order is

+ # determined by mapping the items through the given block to obtain sort

+ # keys, and then sorting the keys according to their natural sort order

+ # (`#<=>`).

+ #

+ # @yield [element] Once for each element.

+ # @yieldreturn a sort key object for the yielded element.

+ # @example

+ # Immutable::Vector["Elephant", "Dog", "Lion"].sort_by { |e| e.size }

+ # # => Immutable::Vector["Dog", "Lion", "Elephant"]

+ #

+ # @return [Vector]

+ def sort_by

+ self.class.new(super)

+ end

+

+ # Drop the first `n` elements and return the rest in a new `Vector`.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C", "D", "E", "F"].drop(2)

+ # # => Immutable::Vector["C", "D", "E", "F"]

+ #

+ # @param n [Integer] The number of elements to remove

+ # @return [Vector]

+ # @raise ArgumentError if `n` is negative.

+ def drop(n)

+ return self if n == 0

+ return self.class.empty if n >= @size

+ raise ArgumentError, 'attempt to drop negative size' if n < 0

+ self.class.new(flatten_suffix(@root, @levels * BITS_PER_LEVEL, n, []))

+ end

+

+ # Return only the first `n` elements in a new `Vector`.

+ #

+ # @example

+ # Immutable::Vector["A", "B", "C", "D", "E", "F"].take(4)

+ # # => Immutable::Vector["A", "B", "C", "D"]

+ #

+ # @param n [Integer] The number of elements to retain

+ # @return [Vector]

+ def take(n)

+ return self if n >= @size

+ self.class.new(super)

+ end

+

+ # Drop elements up to, but not including, the first element for which the

+ # block returns `nil` or `false`. Gather the remaining elements into a new

+ # `Vector`. If no block is given, an `Enumerator` is returned instead.

+ #

+ # @example

+ # Immutable::Vector[1, 3, 5, 7, 6, 4, 2].drop_while { |e| e < 5 }

+ # # => Immutable::Vector[5, 7, 6, 4, 2]

+ #

+ # @return [Vector, Enumerator]

+ def drop_while

+ return enum_for(:drop_while) if not block_given?

+ self.class.new(super)

+ end

+

+ # Gather elements up to, but not including, the first element for which the

+ # block returns `nil` or `false`, and return them in a new `Vector`. If no block

+ # is given, an `Enumerator` is returned instead.

+ #

+ # @example

+ # Immutable::Vector[1, 3, 5, 7, 6, 4, 2].take_while { |e| e < 5 }

+ # # => Immutable::Vector[1, 3]

+ #

+ # @return [Vector, Enumerator]

+ def take_while

+ return enum_for(:take_while) if not block_given?

+ self.class.new(super)

+ end

+

+ # Repetition. Return a new `Vector` built by concatenating `times` copies

+ # of this one together.

+ #

+ # @example

+ # Immutable::Vector["A", "B"] * 3

+ # # => Immutable::Vector["A", "B", "A", "B", "A", "B"]

+ #

+ # @param times [Integer] The number of times to repeat the elements in this vector

+ # @return [Vector]

+ def *(times)

+ return self.class.empty if times == 0

+ return self if times == 1

+ result = (to_a * times)

+ result.is_a?(Array) ? self.class.new(result) : result

+ end

+

+ # Replace a range of indexes with the given object.

+ #

+ # @overload fill(object)

+ # Return a new `Vector` of the same size, with every index set to

+ # `object`.

+ #

+ # @param [Object] object Fill value.

+ # @example

+ # Immutable::Vector["A", "B", "C", "D", "E", "F"].fill("Z")

+ # # => Immutable::Vector["Z", "Z", "Z", "Z", "Z", "Z"]

+ #

+ # @overload fill(object, index)

+ # Return a new `Vector` with all indexes from `index` to the end of the

+ # vector set to `object`.

+ #

+ # @param [Object] object Fill value.

+ # @param [Integer] index Starting index. May be negative.

+ # @example

+ # Immutable::Vector["A", "B", "C", "D", "E", "F"].fill("Z", 3)

+ # # => Immutable::Vector["A", "B", "C", "Z", "Z", "Z"]

+ #

+ # @overload fill(object, index, length)

+ # Return a new `Vector` with `length` indexes, beginning from `index`,

+ # set to `object`. Expands the `Vector` if `length` would extend beyond

+ # the current length.

+ #

+ # @param [Object] object Fill value.

+ # @param [Integer] index Starting index. May be negative.

+ # @param [Integer] length

+ # @example

+ # Immutable::Vector["A", "B", "C", "D", "E", "F"].fill("Z", 3, 2)

+ # # => Immutable::Vector["A", "B", "C", "Z", "Z", "F"]

+ # Immutable::Vector["A", "B"].fill("Z", 1, 5)

+ # # => Immutable::Vector["A", "Z", "Z", "Z", "Z", "Z"]

+ #

+ # @return [Vector]

+ # @raise [IndexError] if index is out of negative range.

+ def fill(object, index = 0, length = nil)

+ raise IndexError if index < -@size

+ index += @size if index < 0

+ length ||= @size - index # to the end of the array, if no length given

+

+ if index < @size

+ suffix = flatten_suffix(@root, @levels * BITS_PER_LEVEL, index, [])

+ suffix.fill(object, 0, length)

+ elsif index == @size

+ suffix = Array.new(length, object)

+ else

+ suffix = Array.new(index - @size, nil).concat(Array.new(length, object))

+ index = @size

+ end

+

+ replace_suffix(index, suffix)

+ end

+

+ # When invoked with a block, yields all combinations of length `n` of items

+ # from the `Vector`, and then returns `self`. There is no guarantee about

+ # which order the combinations will be yielded.

+ #

+ # If no block is given, an `Enumerator` is returned instead.

+ #

+ # @example

+ # v = Immutable::Vector[5, 6, 7, 8]

+ # v.combination(3) { |c| puts "Combination: #{c}" }

+ #

+ # Combination: [5, 6, 7]

+ # Combination: [5, 6, 8]

+ # Combination: [5, 7, 8]

+ # Combination: [6, 7, 8]

+ # #=> Immutable::Vector[5, 6, 7, 8]

+ #

+ # @return [self, Enumerator]

+ def combination(n)

+ return enum_for(:combination, n) if not block_given?

+ return self if n < 0 || @size < n

+ if n == 0

+ yield []

+ elsif n == 1

+ each { |item| yield [item] }

+ elsif n == @size

+ yield to_a

+ else

+ combos = lambda do |result,index,remaining|

+ while @size - index > remaining

+ if remaining == 1

+ yield result.dup << get(index)

+ else

+ combos[result.dup << get(index), index+1, remaining-1]

+ end

+ index += 1

+ end

+ index.upto(@size-1) { |i| result << get(i) }

+ yield result

+ end

+ combos[[], 0, n]

+ end

+ self

+ end

+

+ # When invoked with a block, yields all repeated combinations of length `n` of

+ # items from the `Vector`, and then returns `self`. A "repeated combination" is

+ # one in which any item from the `Vector` can appear consecutively any number of

+ # times.

+ #

+ # There is no guarantee about which order the combinations will be yielded in.

+ #

+ # If no block is given, an `Enumerator` is returned instead.

+ #

+ # @example

+ # v = Immutable::Vector[5, 6, 7, 8]

+ # v.repeated_combination(2) { |c| puts "Combination: #{c}" }

+ #

+ # Combination: [5, 5]

+ # Combination: [5, 6]

+ # Combination: [5, 7]

+ # Combination: [5, 8]

+ # Combination: [6, 6]

+ # Combination: [6, 7]

+ # Combination: [6, 8]

+ # Combination: [7, 7]

+ # Combination: [7, 8]

+ # Combination: [8, 8]

+ # # => Immutable::Vector[5, 6, 7, 8]

+ #

+ # @return [self, Enumerator]

+ def repeated_combination(n)

+ return enum_for(:repeated_combination, n) if not block_given?

+ if n < 0

+ # yield nothing

+ elsif n == 0

+ yield []

+ elsif n == 1

+ each { |item| yield [item] }

+ elsif @size == 0

+ # yield nothing

+ else

+ combos = lambda do |result,index,remaining|

+ while index < @size-1

+ if remaining == 1

+ yield result.dup << get(index)

+ else

+ combos[result.dup << get(index), index, remaining-1]

+ end

+ index += 1

+ end

+ item = get(index)

+ remaining.times { result << item }

+ yield result

+ end

+ combos[[], 0, n]

+ end

+ self

+ end

+

+ # Yields all permutations of length `n` of items from the `Vector`, and then

+ # returns `self`. If no length `n` is specified, permutations of all elements

+ # will be yielded.

+ #

+ # There is no guarantee about which order the permutations will be yielded in.

+ #

+ # If no block is given, an `Enumerator` is returned instead.

+ #

+ # @example

+ # v = Immutable::Vector[5, 6, 7]

+ # v.permutation(2) { |p| puts "Permutation: #{p}" }

+ #

+ # Permutation: [5, 6]

+ # Permutation: [5, 7]

+ # Permutation: [6, 5]

+ # Permutation: [6, 7]

+ # Permutation: [7, 5]

+ # Permutation: [7, 6]

+ # # => Immutable::Vector[5, 6, 7]

+ #

+ # @return [self, Enumerator]

+ def permutation(n = @size)

+ return enum_for(:permutation, n) if not block_given?

+ if n < 0 || @size < n

+ # yield nothing

+ elsif n == 0

+ yield []

+ elsif n == 1

+ each { |item| yield [item] }

+ else

+ used, result = [], []

+ perms = lambda do |index|

+ 0.upto(@size-1) do |i|

+ next if used[i]

+ result[index] = get(i)

+ if index < n-1

+ used[i] = true

+ perms[index+1]

+ used[i] = false

+ else

+ yield result.dup

+ end

+ end

+ end

+ perms[0]

+ end

+ self

+ end

+

+ # When invoked with a block, yields all repeated permutations of length `n` of

+ # items from the `Vector`, and then returns `self`. A "repeated permutation" is

+ # one where any item from the `Vector` can appear any number of times, and in

+ # any position (not just consecutively)

+ #

+ # If no length `n` is specified, permutations of all elements will be yielded.

+ # There is no guarantee about which order the permutations will be yielded in.

+ #

+ # If no block is given, an `Enumerator` is returned instead.

+ #

+ # @example

+ # v = Immutable::Vector[5, 6, 7]

+ # v.repeated_permutation(2) { |p| puts "Permutation: #{p}" }

+ #

+ # Permutation: [5, 5]

+ # Permutation: [5, 6]

+ # Permutation: [5, 7]

+ # Permutation: [6, 5]

+ # Permutation: [6, 6]

+ # Permutation: [6, 7]

+ # Permutation: [7, 5]

+ # Permutation: [7, 6]

+ # Permutation: [7, 7]

+ # # => Immutable::Vector[5, 6, 7]

+ #

+ # @return [self, Enumerator]

+ def repeated_permutation(n = @size)

+ return enum_for(:repeated_permutation, n) if not block_given?

+ if n < 0

+ # yield nothing

+ elsif n == 0

+ yield []

+ elsif n == 1

+ each { |item| yield [item] }

+ else

+ result = []

+ perms = lambda do |index|

+ 0.upto(@size-1) do |i|

+ result[index] = get(i)

+ if index < n-1

+ perms[index+1]

+ else

+ yield result.dup

+ end

+ end

+ end

+ perms[0]

+ end

+ self

+ end

+

+ # Cartesian product or multiplication.

+ #

+ # @overload product(*vectors)

+ # Return a `Vector` of all combinations of elements from this `Vector` and each

+ # of the given vectors or arrays. The length of the returned `Vector` is the product

+ # of `self.size` and the size of each argument vector or array.

+ # @example

+ # v1 = Immutable::Vector[1, 2, 3]

+ # v2 = Immutable::Vector["A", "B"]

+ # v1.product(v2)

+ # # => [[1, "A"], [1, "B"], [2, "A"], [2, "B"], [3, "A"], [3, "B"]]

+ # @overload product

+ # Return the result of multiplying all the items in this `Vector` together.

+ #

+ # @example

+ # Immutable::Vector[1, 2, 3, 4, 5].product # => 120

+ #

+ # @return [Vector]

+ def product(*vectors)

+ # if no vectors passed, return "product" as in result of multiplying all items

+ return super if vectors.empty?

+

+ vectors.unshift(self)

+

+ if vectors.any?(&:empty?)

+ return block_given? ? self : []

+ end

+

+ counters = Array.new(vectors.size, 0)

+

+ bump_counters = lambda do

+ i = vectors.size-1

+ counters[i] += 1

+ while counters[i] == vectors[i].size

+ counters[i] = 0

+ i -= 1

+ return true if i == -1 # we are done

+ counters[i] += 1

+ end

+ false # not done yet

+ end

+ build_array = lambda do

+ array = []

+ counters.each_with_index { |index,i| array << vectors[i][index] }

+ array

+ end

+

+ if block_given?

+ loop do

+ yield build_array[]

+ return self if bump_counters[]

+ end

+ else

+ result = []

+ loop do

+ result << build_array[]

+ return result if bump_counters[]

+ end

+ end

+ end

+

+ # Assume all elements are vectors or arrays and transpose the rows and columns.

+ # In other words, take the first element of each nested vector/array and gather

+ # them together into a new `Vector`. Do likewise for the second, third, and so on

+ # down to the end of each nested vector/array. Gather all the resulting `Vectors`

+ # into a new `Vector` and return it.

+ #

+ # This operation is closely related to {#zip}. The result is almost the same as

+ # calling {#zip} on the first nested vector/array with the others supplied as

+ # arguments.

+ #

+ # @example

+ # Immutable::Vector[["A", 10], ["B", 20], ["C", 30]].transpose

+ # # => Immutable::Vector[Immutable::Vector["A", "B", "C"], Immutable::Vector[10, 20, 30]]

+ #

+ # @return [Vector]

+ # @raise [IndexError] if elements are not of the same size.

+ # @raise [TypeError] if an element does not respond to #size and #[]

+ def transpose

+ return self.class.empty if empty?

+ result = Array.new(first.size) { [] }

+

+ 0.upto(@size-1) do |i|

+ source = get(i)

+ if source.size != result.size

+ raise IndexError, "element size differs (#{source.size} should be #{result.size})"

+ end

+

+ 0.upto(result.size-1) do |j|

+ result[j].push(source[j])

+ end

+ end

+

+ result.map! { |a| self.class.new(a) }

+ self.class.new(result)

+ rescue NoMethodError

+ if any? { |x| !x.respond_to?(:size) || !x.respond_to?(:[]) }

+ bad = find { |x| !x.respond_to?(:size) || !x.respond_to?(:[]) }

+ raise TypeError, "'#{bad.inspect}' must respond to #size and #[] to be transposed"

+ else

+ raise

+ end

+ end

+

+ # Finds a value from this `Vector` which meets the condition defined by the

+ # provided block, using a binary search. The vector must already be sorted

+ # with respect to the block. See Ruby's `Array#bsearch` for details,

+ # behaviour is equivalent.

+ #

+ # @example

+ # v = Immutable::Vector[1, 3, 5, 7, 9, 11, 13]

+ # # Block returns true/false for exact element match:

+ # v.bsearch { |e| e > 4 } # => 5

+ # # Block returns number to match an element in 4 <= e <= 7:

+ # v.bsearch { |e| 1 - e / 4 } # => 7

+ #

+ # @yield Once for at most `log n` elements, where `n` is the size of the

+ # vector. The exact elements and ordering are undefined.

+ # @yieldreturn [Boolean] `true` if this element matches the criteria, `false` otherwise.

+ # @yieldreturn [Integer] See `Array#bsearch` for details.

+ # @yieldparam [Object] element element to be evaluated

+ # @return [Object] The matched element, or `nil` if none found.

+ # @raise TypeError if the block returns a non-numeric, non-boolean, non-nil

+ # value.

+ def bsearch

+ return enum_for(:bsearch) if not block_given?

+ low, high, result = 0, @size, nil

+ while low < high

+ mid = (low + ((high - low) >> 1))

+ val = get(mid)

+ v = yield val

+ if v.is_a? Numeric

+ if v == 0

+ return val

+ elsif v > 0

+ high = mid

+ else

+ low = mid + 1

+ end

+ elsif v == true

+ result = val

+ high = mid

+ elsif !v

+ low = mid + 1

+ else

+ raise TypeError, "wrong argument type #{v.class} (must be numeric, true, false, or nil)"

+ end

+ end

+ result

+ end

+

+ # Return an empty `Vector` instance, of the same class as this one. Useful if you

+ # have multiple subclasses of `Vector` and want to treat them polymorphically.

+ #

+ # @return [Vector]

+ def clear

+ self.class.empty

+ end

+

+ # Return a randomly chosen item from this `Vector`. If the vector is empty, return `nil`.

+ #

+ # @example

+ # Immutable::Vector[1, 2, 3, 4, 5].sample # => 2

+ #

+ # @return [Object]

+ def sample

+ get(rand(@size))

+ end

+

+ # Return a new `Vector` with only the elements at the given `indices`, in the

+ # order specified by `indices`. If any of the `indices` do not exist, `nil`s will

+ # appear in their places.

+ #

+ # @example

+ # v = Immutable::Vector["A", "B", "C", "D", "E", "F"]

+ # v.values_at(2, 4, 5) # => Immutable::Vector["C", "E", "F"]

+ #

+ # @param indices [Array] The indices to retrieve and gather into a new `Vector`

+ # @return [Vector]

+ def values_at(*indices)

+ self.class.new(indices.map { |i| get(i) }.freeze)

+ end

+

+ # Find the index of an element, starting from the end of the vector.

+ # Returns `nil` if no element is found.

+ #

+ # @overload rindex(obj)

+ # Return the index of the last element which is `#==` to `obj`.

+ #

+ # @example

+ # v = Immutable::Vector[7, 8, 9, 7, 8, 9]

+ # v.rindex(8) # => 4

+ #

+ # @overload rindex

+ # Return the index of the last element for which the block returns true.

+ #

+ # @yield [element] Once for each element, last to first, until the block

+ # returns true.

+ # @example

+ # v = Immutable::Vector[7, 8, 9, 7, 8, 9]

+ # v.rindex { |e| e.even? } # => 4

+ #

+ # @return [Integer]

+ def rindex(obj = (missing_arg = true))

+ i = @size - 1

+ if missing_arg

+ if block_given?

+ reverse_each { |item| return i if yield item; i -= 1 }

+ nil

+ else

+ enum_for(:rindex)

+ end

+ else

+ reverse_each { |item| return i if item == obj; i -= 1 }

+ nil

+ end

+ end

+

+ # Assumes all elements are nested, indexable collections, and searches through them,

+ # comparing `obj` with the first element of each nested collection. Return the

+ # first nested collection which matches, or `nil` if none is found.

+ # Behaviour is undefined when elements do not meet assumptions (i.e. are

+ # not indexable collections).

+ #

+ # @example

+ # v = Immutable::Vector[["A", 10], ["B", 20], ["C", 30]]

+ # v.assoc("B") # => ["B", 20]

+ #

+ # @param obj [Object] The object to search for

+ # @return [Object]

+ def assoc(obj)

+ each do |array|

+ next if !array.respond_to?(:[])

+ return array if obj == array[0]

+ end

+ nil

+ end

+

+ # Assumes all elements are nested, indexable collections, and searches through them,

+ # comparing `obj` with the second element of each nested collection. Return

+ # the first nested collection which matches, or `nil` if none is found.

+ # Behaviour is undefined when elements do not meet assumptions (i.e. are

+ # not indexable collections).

+ #

+ # @example

+ # v = Immutable::Vector[["A", 10], ["B", 20], ["C", 30]]

+ # v.rassoc(20) # => ["B", 20]

+ #

+ # @param obj [Object] The object to search for

+ # @return [Object]

+ def rassoc(obj)

+ each do |array|

+ next if !array.respond_to?(:[])

+ return array if obj == array[1]

+ end

+ nil

+ end

+

+ # Return an `Array` with the same elements, in the same order. The returned

+ # `Array` may or may not be frozen.

+ #

+ # @return [Array]

+ def to_a

+ if @levels == 0

+ # When initializing a Vector with 32 or less items, we always make

+ # sure @root is frozen, so we can return it directly here

+ @root

+ else

+ flatten_node(@root, @levels * BITS_PER_LEVEL, [])

+ end

+ end

+ alias to_ary to_a

+

+ # Return true if `other` has the same type and contents as this `Vector`.

+ #

+ # @param other [Object] The collection to compare with

+ # @return [Boolean]

+ def eql?(other)

+ return true if other.equal?(self)

+ return false unless instance_of?(other.class) && @size == other.size

+ @root.eql?(other.instance_variable_get(:@root))

+ end

+

+ # See `Object#hash`.

+ # @return [Integer]

+ def hash

+ reduce(0) { |hash, item| (hash << 5) - hash + item.hash }

+ end

+

+ # Return `self`. Since this is an immutable object duplicates are

+ # equivalent.

+ # @return [Vector]

+ def dup

+ self

+ end

+ alias clone dup

+

+ # @return [::Array]

+ # @private

+ def marshal_dump

+ to_a

+ end

+

+ # @private

+ def marshal_load(array)

+ initialize(array.freeze)

+ end

+

+ private

+

+ def traverse_depth_first(node, level, &block)

+ return node.each(&block) if level == 0

+ node.each { |child| traverse_depth_first(child, level - 1, &block) }

+ end

+

+ def reverse_traverse_depth_first(node, level, &block)

+ return node.reverse_each(&block) if level == 0

+ node.reverse_each { |child| reverse_traverse_depth_first(child, level - 1, &block) }

+ end

+

+ def leaf_node_for(node, bitshift, index)

+ while bitshift > 0

+ node = node[(index >> bitshift) & INDEX_MASK]

+ bitshift -= BITS_PER_LEVEL

+ end

+ node

+ end

+

+ def update_root(index, item)

+ root, levels = @root, @levels

+ while index >= (1 << (BITS_PER_LEVEL * (levels + 1)))

+ root = [root].freeze

+ levels += 1

+ end

+ new_root = update_leaf_node(root, levels * BITS_PER_LEVEL, index, item)

+ if new_root.equal?(root)

+ self

+ else

+ self.class.alloc(new_root, @size > index ? @size : index + 1, levels)

+ end

+ end

+

+ def update_leaf_node(node, bitshift, index, item)

+ slot_index = (index >> bitshift) & INDEX_MASK

+ if bitshift > 0

+ old_child = node[slot_index] || []

+ item = update_leaf_node(old_child, bitshift - BITS_PER_LEVEL, index, item)

+ end

+ existing_item = node[slot_index]

+ if existing_item.equal?(item)

+ node

+ else

+ node.dup.tap { |n| n[slot_index] = item }.freeze

+ end

+ end

+

+ def flatten_range(node, bitshift, from, to)

+ from_slot = (from >> bitshift) & INDEX_MASK

+ to_slot = (to >> bitshift) & INDEX_MASK

+

+ if bitshift == 0 # are we at the bottom?

+ node.slice(from_slot, to_slot-from_slot+1)

+ elsif from_slot == to_slot

+ flatten_range(node[from_slot], bitshift - BITS_PER_LEVEL, from, to)

+ else

+ # the following bitmask can be used to pick out the part of the from/to indices

+ # which will be used to direct path BELOW this node

+ mask = ((1 << bitshift) - 1)

+ result = []

+

+ if from & mask == 0

+ flatten_node(node[from_slot], bitshift - BITS_PER_LEVEL, result)

+ else

+ result.concat(flatten_range(node[from_slot], bitshift - BITS_PER_LEVEL, from, from | mask))

+ end

+

+ (from_slot+1).upto(to_slot-1) do |slot_index|

+ flatten_node(node[slot_index], bitshift - BITS_PER_LEVEL, result)

+ end

+

+ if to & mask == mask

+ flatten_node(node[to_slot], bitshift - BITS_PER_LEVEL, result)

+ else

+ result.concat(flatten_range(node[to_slot], bitshift - BITS_PER_LEVEL, to & ~mask, to))

+ end

+

+ result

+ end

+ end

+

+ def flatten_node(node, bitshift, result)

+ if bitshift == 0

+ result.concat(node)

+ elsif bitshift == BITS_PER_LEVEL

+ node.each { |a| result.concat(a) }

+ else

+ bitshift -= BITS_PER_LEVEL

+ node.each { |a| flatten_node(a, bitshift, result) }

+ end

+ result

+ end

+

+ def subsequence(from, length)

+ return nil if from > @size || from < 0 || length < 0

+ length = @size - from if @size < from + length

+ return self.class.empty if length == 0

+ self.class.new(flatten_range(@root, @levels * BITS_PER_LEVEL, from, from + length - 1))

+ end

+

+ def flatten_suffix(node, bitshift, from, result)

+ from_slot = (from >> bitshift) & INDEX_MASK

+

+ if bitshift == 0

+ if from_slot == 0

+ result.concat(node)

+ else

+ result.concat(node.slice(from_slot, 32)) # entire suffix of node. excess length is ignored by #slice

+ end

+ else

+ mask = ((1 << bitshift) - 1)

+ if from & mask == 0

+ from_slot.upto(node.size-1) do |i|

+ flatten_node(node[i], bitshift - BITS_PER_LEVEL, result)

+ end

+ elsif (child = node[from_slot])

+ flatten_suffix(child, bitshift - BITS_PER_LEVEL, from, result)

+ (from_slot+1).upto(node.size-1) do |i|

+ flatten_node(node[i], bitshift - BITS_PER_LEVEL, result)

+ end

+ end

+ result

+ end

+ end

+

+ def replace_suffix(from, suffix)

+ # new suffix can go directly after existing elements

+ raise IndexError if from > @size

+ root, levels = @root, @levels

+

+ if (from >> (BITS_PER_LEVEL * (@levels + 1))) != 0

+ # index where new suffix goes doesn't fall within current tree

+ # we will need to deepen tree

+ root = [root].freeze

+ levels += 1

+ end

+

+ new_size = from + suffix.size

+ root = replace_node_suffix(root, levels * BITS_PER_LEVEL, from, suffix)

+

+ if !suffix.empty?

+ levels.times { suffix = suffix.each_slice(32).to_a }

+ root.concat(suffix)

+ while root.size > 32

+ root = root.each_slice(32).to_a

+ levels += 1

+ end

+ else

+ while root.size == 1 && levels > 0

+ root = root[0]

+ levels -= 1

+ end

+ end

+

+ self.class.alloc(root.freeze, new_size, levels)

+ end

+

+ def replace_node_suffix(node, bitshift, from, suffix)

+ from_slot = (from >> bitshift) & INDEX_MASK

+

+ if bitshift == 0

+ if from_slot == 0

+ suffix.shift(32)

+ else

+ node.take(from_slot).concat(suffix.shift(32 - from_slot))

+ end

+ else

+ mask = ((1 << bitshift) - 1)

+ if from & mask == 0

+ if from_slot == 0

+ new_node = suffix.shift(32 * (1 << bitshift))

+ while bitshift != 0

+ new_node = new_node.each_slice(32).to_a

+ bitshift -= BITS_PER_LEVEL

+ end

+ new_node

+ else

+ result = node.take(from_slot)

+ remainder = suffix.shift((32 - from_slot) * (1 << bitshift))

+ while bitshift != 0

+ remainder = remainder.each_slice(32).to_a

+ bitshift -= BITS_PER_LEVEL

+ end

+ result.concat(remainder)

+ end

+ elsif (child = node[from_slot])

+ result = node.take(from_slot)

+ result.push(replace_node_suffix(child, bitshift - BITS_PER_LEVEL, from, suffix))

+ remainder = suffix.shift((31 - from_slot) * (1 << bitshift))

+ while bitshift != 0

+ remainder = remainder.each_slice(32).to_a

+ bitshift -= BITS_PER_LEVEL

+ end

+ result.concat(remainder)

+ else

+ raise "Shouldn't happen"

+ end

+ end

+ end

+ end

+

+ # The canonical empty `Vector`. Returned by `Vector[]` when

+ # invoked with no arguments; also returned by `Vector.empty`. Prefer using this

+ # one rather than creating many empty vectors using `Vector.new`.

+ #

+ # @private

+ EmptyVector = Immutable::Vector.empty

+

+

+ # `Immutable::Set` is a collection of unordered values with no duplicates. Testing whether

+ # an object is present in the `Set` can be done in constant time. `Set` is also `Enumerable`, so you can

+ # iterate over the members of the set with {#each}, transform them with {#map}, filter

+ # them with {#select}, and so on. Some of the `Enumerable` methods are overridden to

+ # return `immutable-ruby` collections.

+ #

+ # Like the `Set` class in Ruby's standard library, which we will call RubySet,

+ # `Immutable::Set` defines equivalency of objects using `#hash` and `#eql?`. No two

+ # objects with the same `#hash` code, and which are also `#eql?`, can coexist in the

+ # same `Set`. If one is already in the `Set`, attempts to add another one will have

+ # no effect.

+ #

+ # `Set`s have no natural ordering and cannot be compared using `#<=>`. However, they

+ # define {#<}, {#>}, {#<=}, and {#>=} as shorthand for {#proper_subset?},

+ # {#proper_superset?}, {#subset?}, and {#superset?} respectively.

+ #

+ # The basic set-theoretic operations {#union}, {#intersection}, {#difference}, and

+ # {#exclusion} work with any `Enumerable` object.

+ #

+ # A `Set` can be created in either of the following ways:

+ #

+ # Immutable::Set.new([1, 2, 3]) # any Enumerable can be used to initialize

+ # Immutable::Set['A', 'B', 'C', 'D']

+ #

+ # The latter 2 forms of initialization can be used with your own, custom subclasses

+ # of `Immutable::Set`.

+ #

+ # Unlike RubySet, all methods which you might expect to "modify" an `Immutable::Set`

+ # actually return a new set and leave the existing one unchanged.

+ #

+ # @example

+ # set1 = Immutable::Set[1, 2] # => Immutable::Set[1, 2]

+ # set2 = Immutable::Set[1, 2] # => Immutable::Set[1, 2]

+ # set1 == set2 # => true

+ # set3 = set1.add("foo") # => Immutable::Set[1, 2, "foo"]

+ # set3 - set2 # => Immutable::Set["foo"]

+ # set3.subset?(set1) # => false

+ # set1.subset?(set3) # => true

+ #

+ class Set

+ include Immutable::Enumerable

+

+ class << self

+ # Create a new `Set` populated with the given items.

+ # @return [Set]

+ def [](*items)

+ items.empty? ? empty : new(items)

+ end

+

+ # Return an empty `Set`. If used on a subclass, returns an empty instance

+ # of that class.

+ #

+ # @return [Set]

+ def empty

+ @empty ||= new

+ end

+

+ # "Raw" allocation of a new `Set`. Used internally to create a new

+ # instance quickly after obtaining a modified {Trie}.

+ #

+ # @return [Set]

+ # @private

+ def alloc(trie = EmptyTrie)

+ allocate.tap { |s| s.instance_variable_set(:@trie, trie) }.freeze

+ end

+ end

+

+ def initialize(items=[])

+ @trie = Trie.new(0)

+ items.each { |item| @trie.put!(item, nil) }

+ freeze

+ end

+

+ # Return `true` if this `Set` contains no items.

+ # @return [Boolean]

+ def empty?

+ @trie.empty?

+ end

+

+ # Return the number of items in this `Set`.

+ # @return [Integer]

+ def size

+ @trie.size

+ end

+ alias length size

+

+ # Return a new `Set` with `item` added. If `item` is already in the set,

+ # return `self`.

+ #

+ # @example

+ # Immutable::Set[1, 2, 3].add(4) # => Immutable::Set[1, 2, 4, 3]

+ # Immutable::Set[1, 2, 3].add(2) # => Immutable::Set[1, 2, 3]

+ #

+ # @param item [Object] The object to add

+ # @return [Set]

+ def add(item)

+ include?(item) ? self : self.class.alloc(@trie.put(item, nil))

+ end

+ alias << add

+

+ # If `item` is not a member of this `Set`, return a new `Set` with `item` added.

+ # Otherwise, return `false`.

+ #

+ # @example

+ # Immutable::Set[1, 2, 3].add?(4) # => Immutable::Set[1, 2, 4, 3]

+ # Immutable::Set[1, 2, 3].add?(2) # => false

+ #

+ # @param item [Object] The object to add

+ # @return [Set, false]

+ def add?(item)

+ !include?(item) && add(item)

+ end

+

+ # Return a new `Set` with `item` removed. If `item` is not a member of the set,

+ # return `self`.

+ #

+ # @example

+ # Immutable::Set[1, 2, 3].delete(1) # => Immutable::Set[2, 3]

+ # Immutable::Set[1, 2, 3].delete(99) # => Immutable::Set[1, 2, 3]

+ #

+ # @param item [Object] The object to remove

+ # @return [Set]

+ def delete(item)

+ trie = @trie.delete(item)

+ new_trie(trie)

+ end

+

+ # If `item` is a member of this `Set`, return a new `Set` with `item` removed.

+ # Otherwise, return `false`.

+ #

+ # @example

+ # Immutable::Set[1, 2, 3].delete?(1) # => Immutable::Set[2, 3]

+ # Immutable::Set[1, 2, 3].delete?(99) # => false

+ #

+ # @param item [Object] The object to remove

+ # @return [Set, false]

+ def delete?(item)

+ include?(item) && delete(item)

+ end

+

+ # Call the block once for each item in this `Set`. No specific iteration order

+ # is guaranteed, but the order will be stable for any particular `Set`. If

+ # no block is given, an `Enumerator` is returned instead.

+ #

+ # @example

+ # Immutable::Set["Dog", "Elephant", "Lion"].each { |e| puts e }

+ # Elephant

+ # Dog

+ # Lion

+ # # => Immutable::Set["Dog", "Elephant", "Lion"]

+ #

+ # @yield [item] Once for each item.

+ # @return [self, Enumerator]

+ def each

+ return to_enum if not block_given?

+ @trie.each { |key, _| yield(key) }

+ self

+ end

+

+ # Call the block once for each item in this `Set`. Iteration order will be

+ # the opposite of {#each}. If no block is given, an `Enumerator` is

+ # returned instead.

+ #

+ # @example

+ # Immutable::Set["Dog", "Elephant", "Lion"].reverse_each { |e| puts e }

+ # Lion

+ # Dog

+ # Elephant

+ # # => Immutable::Set["Dog", "Elephant", "Lion"]

+ #

+ # @yield [item] Once for each item.

+ # @return [self]

+ def reverse_each

+ return enum_for(:reverse_each) if not block_given?

+ @trie.reverse_each { |key, _| yield(key) }

+ self

+ end

+

+ # Return a new `Set` with all the items for which the block returns true.

+ #

+ # @example

+ # Immutable::Set["Elephant", "Dog", "Lion"].select { |e| e.size >= 4 }

+ # # => Immutable::Set["Elephant", "Lion"]

+ # @yield [item] Once for each item.

+ # @return [Set]

+ def select

+ return enum_for(:select) unless block_given?

+ trie = @trie.select { |key, _| yield(key) }

+ new_trie(trie)

+ end

+ alias find_all select

+ alias keep_if select

+

+ # Call the block once for each item in this `Set`. All the values returned

+ # from the block will be gathered into a new `Set`. If no block is given,

+ # an `Enumerator` is returned instead.

+ #

+ # @example

+ # Immutable::Set["Cat", "Elephant", "Dog", "Lion"].map { |e| e.size }

+ # # => Immutable::Set[8, 4, 3]

+ #

+ # @yield [item] Once for each item.

+ # @return [Set]

+ def map

+ return enum_for(:map) if not block_given?

+ return self if empty?

+ self.class.new(super)

+ end

+ alias collect map

+

+ # Return `true` if the given item is present in this `Set`. More precisely,

+ # return `true` if an object with the same `#hash` code, and which is also `#eql?`

+ # to the given object is present.

+ #

+ # @example

+ # Immutable::Set["A", "B", "C"].include?("B") # => true

+ # Immutable::Set["A", "B", "C"].include?("Z") # => false

+ #

+ # @param object [Object] The object to check for

+ # @return [Boolean]

+ def include?(object)

+ @trie.key?(object)

+ end

+ alias member? include?

+

+ # Return a member of this `Set`. The member chosen will be the first one which

+ # would be yielded by {#each}. If the set is empty, return `nil`.

+ #

+ # @example

+ # Immutable::Set["A", "B", "C"].first # => "C"

+ #

+ # @return [Object]

+ def first

+ (entry = @trie.at(0)) && entry[0]

+ end

+

+ # Return a {SortedSet} which contains the same items as this `Set`, ordered by

+ # the given comparator block.

+ #

+ # @example

+ # Immutable::Set["Elephant", "Dog", "Lion"].sort

+ # # => Immutable::SortedSet["Dog", "Elephant", "Lion"]

+ # Immutable::Set["Elephant", "Dog", "Lion"].sort { |a,b| a.size <=> b.size }

+ # # => Immutable::SortedSet["Dog", "Lion", "Elephant"]

+ #

+ # @yield [a, b] Any number of times with different pairs of elements.

+ # @yieldreturn [Integer] Negative if the first element should be sorted

+ # lower, positive if the latter element, or 0 if

+ # equal.

+ # @return [SortedSet]

+ def sort(&comparator)

+ SortedSet.new(to_a, &comparator)

+ end

+

+ # Return a {SortedSet} which contains the same items as this `Set`, ordered

+ # by mapping each item through the provided block to obtain sort keys, and

+ # then sorting the keys.

+ #

+ # @example

+ # Immutable::Set["Elephant", "Dog", "Lion"].sort_by { |e| e.size }

+ # # => Immutable::SortedSet["Dog", "Lion", "Elephant"]

+ #

+ # @yield [item] Once for each item to create the set, and then potentially

+ # again depending on what operations are performed on the

+ # returned {SortedSet}. As such, it is recommended that the

+ # block be a pure function.

+ # @yieldreturn [Object] sort key for the item

+ # @return [SortedSet]

+ def sort_by(&mapper)

+ SortedSet.new(to_a, &mapper)

+ end

+

+ # Return a new `Set` which contains all the members of both this `Set` and `other`.

+ # `other` can be any `Enumerable` object.

+ #

+ # @example

+ # Immutable::Set[1, 2] | Immutable::Set[2, 3] # => Immutable::Set[1, 2, 3]

+ #

+ # @param other [Enumerable] The collection to merge with

+ # @return [Set]

+ def union(other)

+ if other.is_a?(Immutable::Set)

+ if other.size > size

+ small_set_pairs = @trie

+ large_set_trie = other.instance_variable_get(:@trie)

+ else

+ small_set_pairs = other.instance_variable_get(:@trie)

+ large_set_trie = @trie

+ end

+ else

+ if other.respond_to?(:lazy)

+ small_set_pairs = other.lazy.map { |e| [e, nil] }

+ else

+ small_set_pairs = other.map { |e| [e, nil] }

+ end

+ large_set_trie = @trie

+ end

+

+ trie = large_set_trie.bulk_put(small_set_pairs)

+ new_trie(trie)

+ end

+ alias | union

+ alias + union

+ alias merge union

+

+ # Return a new `Set` which contains all the items which are members of both

+ # this `Set` and `other`. `other` can be any `Enumerable` object.

+ #

+ # @example

+ # Immutable::Set[1, 2] & Immutable::Set[2, 3] # => Immutable::Set[2]

+ #

+ # @param other [Enumerable] The collection to intersect with

+ # @return [Set]

+ def intersection(other)

+ if other.size < @trie.size

+ if other.is_a?(Immutable::Set)

+ trie = other.instance_variable_get(:@trie).select { |key, _| include?(key) }

+ else

+ trie = Trie.new(0)

+ other.each { |obj| trie.put!(obj, nil) if include?(obj) }

+ end

+ else

+ trie = @trie.select { |key, _| other.include?(key) }

+ end

+ new_trie(trie)

+ end

+ alias & intersection

+

+ # Return a new `Set` with all the items in `other` removed. `other` can be

+ # any `Enumerable` object.

+ #

+ # @example

+ # Immutable::Set[1, 2] - Immutable::Set[2, 3] # => Immutable::Set[1]

+ #

+ # @param other [Enumerable] The collection to subtract from this set

+ # @return [Set]

+ def difference(other)

+ trie = if (@trie.size <= other.size) && (other.is_a?(Immutable::Set) || (defined?(::Set) && other.is_a?(::Set)))

+ @trie.select { |key, _| !other.include?(key) }

+ else

+ @trie.bulk_delete(other)

+ end

+ new_trie(trie)

+ end

+ alias subtract difference

+ alias - difference

+

+ # Return a new `Set` which contains all the items which are members of this

+ # `Set` or of `other`, but not both. `other` can be any `Enumerable` object.

+ #

+ # @example

+ # Immutable::Set[1, 2] ^ Immutable::Set[2, 3] # => Immutable::Set[1, 3]

+ #

+ # @param other [Enumerable] The collection to take the exclusive disjunction of

+ # @return [Set]

+ def exclusion(other)

+ ((self | other) - (self & other))

+ end

+ alias ^ exclusion

+

+ # Return `true` if all items in this `Set` are also in `other`.

+ #

+ # @example

+ # Immutable::Set[2, 3].subset?(Immutable::Set[1, 2, 3]) # => true

+ #

+ # @param other [Set]

+ # @return [Boolean]

+ def subset?(other)

+ return false if other.size < size

+

+ # This method has the potential to be very slow if 'other' is a large Array, so to avoid that,

+ # we convert those Arrays to Sets before checking presence of items

+ # Time to convert Array -> Set is linear in array.size

+ # Time to check for presence of all items in an Array is proportional to set.size * array.size

+ # Note that both sides of that equation have array.size -- hence those terms cancel out,

+ # and the break-even point is solely dependent on the size of this collection

+ # After doing some benchmarking to estimate the constants, it appears break-even is at ~190 items

+ # We also check other.size, to avoid the more expensive #is_a? checks in cases where it doesn't matter

+ #

+ if other.size >= 150 && @trie.size >= 190 && !(other.is_a?(Immutable::Set) || other.is_a?(::Set))

+ other = ::Set.new(other)

+ end

+ all? { |item| other.include?(item) }

+ end

+ alias <= subset?

+

+ # Return `true` if all items in `other` are also in this `Set`.

+ #

+ # @example

+ # Immutable::Set[1, 2, 3].superset?(Immutable::Set[2, 3]) # => true

+ #

+ # @param other [Set]

+ # @return [Boolean]

+ def superset?(other)

+ other.subset?(self)

+ end

+ alias >= superset?

+

+ # Returns `true` if `other` contains all the items in this `Set`, plus at least

+ # one item which is not in this set.

+ #

+ # @example

+ # Immutable::Set[2, 3].proper_subset?(Immutable::Set[1, 2, 3]) # => true

+ # Immutable::Set[1, 2, 3].proper_subset?(Immutable::Set[1, 2, 3]) # => false

+ #

+ # @param other [Set]

+ # @return [Boolean]

+ def proper_subset?(other)

+ return false if other.size <= size

+ # See comments above

+ if other.size >= 150 && @trie.size >= 190 && !(other.is_a?(Immutable::Set) || other.is_a?(::Set))

+ other = ::Set.new(other)

+ end

+ all? { |item| other.include?(item) }

+ end

+ alias < proper_subset?

+

+ # Returns `true` if this `Set` contains all the items in `other`, plus at least

+ # one item which is not in `other`.

+ #

+ # @example

+ # Immutable::Set[1, 2, 3].proper_superset?(Immutable::Set[2, 3]) # => true

+ # Immutable::Set[1, 2, 3].proper_superset?(Immutable::Set[1, 2, 3]) # => false

+ #

+ # @param other [Set]

+ # @return [Boolean]

+ def proper_superset?(other)

+ other.proper_subset?(self)

+ end

+ alias > proper_superset?

+

+ # Return `true` if this `Set` and `other` do not share any items.

+ #

+ # @example

+ # Immutable::Set[1, 2].disjoint?(Immutable::Set[8, 9]) # => true

+ #

+ # @param other [Set]

+ # @return [Boolean]

+ def disjoint?(other)

+ if other.size <= size

+ other.each { |item| return false if include?(item) }

+ else

+ # See comment on #subset?

+ if other.size >= 150 && @trie.size >= 190 && !(other.is_a?(Immutable::Set) || other.is_a?(::Set))

+ other = ::Set.new(other)

+ end

+ each { |item| return false if other.include?(item) }

+ end

+ true

+ end

+

+ # Return `true` if this `Set` and `other` have at least one item in common.

+ #

+ # @example

+ # Immutable::Set[1, 2].intersect?(Immutable::Set[2, 3]) # => true

+ #

+ # @param other [Set]

+ # @return [Boolean]

+ def intersect?(other)

+ !disjoint?(other)

+ end

+

+ # Recursively insert the contents of any nested `Set`s into this `Set`, and

+ # remove them.

+ #

+ # @example

+ # Immutable::Set[Immutable::Set[1, 2], Immutable::Set[3, 4]].flatten

+ # # => Immutable::Set[1, 2, 3, 4]

+ #

+ # @return [Set]

+ def flatten

+ reduce(self.class.empty) do |set, item|

+ next set.union(item.flatten) if item.is_a?(Set)

+ set.add(item)

+ end

+ end

+

+ alias group group_by

+ alias classify group_by

+

+ # Return a randomly chosen item from this `Set`. If the set is empty, return `nil`.

+ #

+ # @example

+ # Immutable::Set[1, 2, 3, 4, 5].sample # => 3

+ #

+ # @return [Object]

+ def sample

+ empty? ? nil : @trie.at(rand(size))[0]

+ end

+

+ # Return an empty `Set` instance, of the same class as this one. Useful if you

+ # have multiple subclasses of `Set` and want to treat them polymorphically.

+ #

+ # @return [Set]

+ def clear

+ self.class.empty

+ end

+

+ # Return true if `other` has the same type and contents as this `Set`.

+ #

+ # @param other [Object] The object to compare with

+ # @return [Boolean]

+ def eql?(other)

+ return true if other.equal?(self)

+ return false if not instance_of?(other.class)

+ other_trie = other.instance_variable_get(:@trie)

+ return false if @trie.size != other_trie.size

+ @trie.each do |key, _|

+ return false if !other_trie.key?(key)

+ end

+ true

+ end

+ alias == eql?

+

+ # See `Object#hash`.

+ # @return [Integer]

+ def hash

+ reduce(0) { |hash, item| (hash << 5) - hash + item.hash }

+ end

+

+ # Return `self`. Since this is an immutable object duplicates are

+ # equivalent.

+ # @return [Set]

+ def dup

+ self

+ end

+ alias clone dup

+

+ undef :"<=>" # Sets are not ordered, so Enumerable#<=> will give a meaningless result

+ undef :each_index # Set members cannot be accessed by 'index', so #each_index is not meaningful

+

+ # Return `self`.

+ #

+ # @return [self]

+ def to_set

+ self

+ end

+

+ # @private

+ def marshal_dump

+ output = {}

+ each do |key|

+ output[key] = nil

+ end

+ output

+ end

+

+ # @private

+ def marshal_load(dictionary)

+ @trie = dictionary.reduce(EmptyTrie) do |trie, key_value|

+ trie.put(key_value.first, nil)

+ end

+ end

+

+ private

+

+ def new_trie(trie)

+ if trie.empty?

+ self.class.empty

+ elsif trie.equal?(@trie)

+ self

+ else

+ self.class.alloc(trie)

+ end

+ end

+ end

+

+ # The canonical empty `Set`. Returned by `Set[]` when

+ # invoked with no arguments; also returned by `Set.empty`. Prefer using this

+ # one rather than creating many empty sets using `Set.new`.

+ #

+ # @private

+ EmptySet = Immutable::Set.empty

+end

+# Definition of Immutable::Hash is in a separate file to avoid circular

+# dependency warnings caused by dependencies between Hash ↔ Vector and

+# Hash ↔ Set

+require 'immutable/_core'

+# Definition of Immutable::Vector is in a separate file to avoid

+# circular dependency warnings

+require 'immutable/_core'

+# Definition of Immutable::Vector is in a separate file to avoid

+# circular dependency warnings

+require 'immutable/_core'

+ VERSION = '0.2.0'