struct StaticArray(T, N)

Overview

A fixed-size, stack allocated array.

StaticArray is a generic type with type argument T specifying the type of its elements and N the fixed size. For example StaticArray(Int32, 3) is a static array of Int32 with three elements.

Instantiations of this static array type:

StaticArray(Int32, 3).new(42)           # => StaticArray[42, 42, 42]
StaticArray(Int32, 3).new { |i| i * 2 } # => StaticArray[0, 2, 4]
StaticArray[0, 8, 15]                   # => StaticArray[0, 8, 15]

This type can also be expressed as Int32[3] (only in type grammar). A typical use case is in combination with uninitialized:

ints = uninitialized Int32[3]
ints[0] = 0
ints[1] = 8
ints[2] = 15

For number types there is also Number.static_array which can be used to initialize a static array:

Int32.static_array(0, 8, 15) # => StaticArray[0, 8, 15]

The generic argument type N is a special case in the type grammar as it doesn't specify a type but a size. Its value can be an Int32 literal or constant.

Included Modules

Defined in:

static_array.cr

Constructors

  • .new(& : Int32 -> T)

    Creates a new static array and invokes the block once for each index of the array, assigning the block's value in that index.

  • .new(value : T)

    Creates a new static array filled with the given value.

Instance Method Summary

Macro Summary

Instance methods inherited from module Indexable::Mutable(T)

[]=(index : Int, value : T) : T []=, fill(value : T) : self
fill(*, offset : Int = 0, & : Int32 -> T) : self fill
, map!(& : T -> _) : self map!, map_with_index!(offset = 0, & : T, Int32 -> _) : self map_with_index!, reverse! : self reverse!, rotate!(n : Int = 1) : self rotate!, shuffle!(random = Random::DEFAULT) : self shuffle!, sort! : self
sort!(&block : T, T -> U) : self forall U sort!
, sort_by!(&block : T -> _) : self sort_by!, swap(index0 : Int, index1 : Int) : self swap, unsafe_put(index : Int, value : T) unsafe_put, unstable_sort! : self
unstable_sort!(&block : T, T -> U) : self forall U unstable_sort!
, unstable_sort_by!(&block : T -> _) : self unstable_sort_by!, update(index : Int, & : T -> _) : T update

Instance methods inherited from module Indexable(T)

[](index : Int) [], []?(index : Int) []?, bsearch(& : T -> _) bsearch, bsearch_index(& : T, Int32 -> _) bsearch_index, cartesian_product(*others : Indexable) cartesian_product, combinations(size : Int = self.size) combinations, dig(index : Int, *subindexes) dig, dig?(index : Int, *subindexes) dig?, each(& : T -> )
each
each(*, start : Int, count : Int, & : T -> )
each(*, within range : Range, & : T -> ) each
, each_cartesian(*others : Indexable, &)
each_cartesian(*others : Indexable) each_cartesian
, each_combination(size : Int = self.size, reuse = false, &) : Nil
each_combination(size : Int = self.size, reuse = false) each_combination
, each_index(& : Int32 -> ) : Nil
each_index
each_index(*, start : Int, count : Int, &) each_index
, each_permutation(size : Int = self.size, reuse = false, &) : Nil
each_permutation(size : Int = self.size, reuse = false) each_permutation
, each_repeated_combination(size : Int = self.size, reuse = false, &) : Nil
each_repeated_combination(size : Int = self.size, reuse = false) each_repeated_combination
, empty? : Bool empty?, equals?(other : Indexable, &) : Bool
equals?(other, &) equals?
, fetch(index : Int, &)
fetch(index, default) fetch
, first(&) first, hash(hasher) hash, index(object, offset : Int = 0)
index(offset : Int = 0, & : T -> ) index
, join(separator : String | Char | Number = "") : String join, last : T
last(&) last
, last? : T? last?, permutations(size : Int = self.size) : Array(Array(T)) permutations, repeated_combinations(size : Int = self.size) : Array(Array(T)) repeated_combinations, reverse_each(& : T -> ) : Nil
reverse_each reverse_each
, rindex(value, offset = size - 1)
rindex(offset = size - 1, & : T -> ) rindex
, sample(n : Int, random = Random::DEFAULT) : Array(T)
sample(random = Random::DEFAULT) sample
, size size, to_a : Array(T) to_a, unsafe_fetch(index : Int) unsafe_fetch, values_at(*indexes : Int) values_at

Class methods inherited from module Indexable(T)

cartesian_product(indexables : Indexable(Indexable)) cartesian_product, each_cartesian(indexables : Indexable(Indexable), reuse = false, &)
each_cartesian(indexables : Indexable(Indexable), reuse = false) each_cartesian

Instance methods inherited from module Enumerable(T)

accumulate(initial : U) : Array(U) forall U
accumulate : Array(T)
accumulate(initial : U, &block : U, T -> U) : Array(U) forall U
accumulate(&block : T, T -> T) : Array(T) accumulate
, all?(& : T -> ) : Bool
all?(pattern) : Bool
all? : Bool all?
, any?(& : T -> ) : Bool
any?(pattern) : Bool
any? : Bool any?
, chunks(&block : T -> U) forall U chunks, compact_map(& : T -> _) compact_map, count(& : T -> ) : Int32
count(item) : Int32 count
, cycle(n, & : T -> ) : Nil
cycle(& : T -> ) : Nil cycle
, each(& : T -> ) each, each_cons(count : Int, reuse = false, &) each_cons, each_cons_pair(& : T, T -> ) : Nil each_cons_pair, each_slice(count : Int, reuse = false, &) each_slice, each_with_index(offset = 0, &) each_with_index, each_with_object(obj : U, & : T, U -> ) : U forall U each_with_object, empty? : Bool empty?, find(if_none = nil, & : T -> ) find, first(&)
first(count : Int) : Array(T)
first : T first
, first? : T? first?, flat_map(& : T -> _) flat_map, group_by(& : T -> U) forall U group_by, in_groups_of(size : Int, filled_up_with : U = nil) forall U
in_groups_of(size : Int, filled_up_with : U = nil, reuse = false, &) forall U in_groups_of
, includes?(obj) : Bool includes?, index(& : T -> ) : Int32?
index(obj) : Int32? index
, index_by(& : T -> U) : Hash(U, T) forall U index_by, join(io : IO, separator = "") : Nil
join(separator, io : IO) : Nil
join(separator = "") : String
join(io : IO, separator = "", & : T, IO -> )
join(separator, io : IO, &)
join(separator = "", & : T -> ) join
, map(& : T -> U) : Array(U) forall U map, map_with_index(offset = 0, & : T, Int32 -> U) : Array(U) forall U map_with_index, max : T max, max? : T? max?, max_by(& : T -> U) : T forall U max_by, max_by?(& : T -> U) : T? forall U max_by?, max_of(& : T -> U) : U forall U max_of, max_of?(& : T -> U) : U? forall U max_of?, min : T min, min? : T? min?, min_by(& : T -> U) : T forall U min_by, min_by?(& : T -> U) : T? forall U min_by?, min_of(& : T -> U) : U forall U min_of, min_of?(& : T -> U) : U? forall U min_of?, minmax : Tuple(T, T) minmax, minmax? : Tuple(T?, T?) minmax?, minmax_by(& : T -> U) : Tuple(T, T) forall U minmax_by, minmax_by?(& : T -> U) : Tuple(T, T) | Tuple(Nil, Nil) forall U minmax_by?, minmax_of(& : T -> U) : Tuple(U, U) forall U minmax_of, minmax_of?(& : T -> U) : Tuple(U, U) | Tuple(Nil, Nil) forall U minmax_of?, none?(& : T -> ) : Bool
none?(pattern) : Bool
none? : Bool none?
, one?(& : T -> ) : Bool
one?(pattern) : Bool
one? : Bool one?
, partition(& : T -> ) : Tuple(Array(T), Array(T)) partition, product(initial : Number)
product
product(initial : Number, & : T -> )
product(& : T -> _) product
, reduce(memo, &)
reduce(&) reduce
, reduce?(&) reduce?, reject(& : T -> )
reject(type : U.class) forall U
reject(pattern) : Array(T) reject
, sample(n : Int, random = Random::DEFAULT) : Array(T)
sample(random = Random::DEFAULT) : T sample
, select(& : T -> )
select(type : U.class) : Array(U) forall U
select(pattern) : Array(T) select
, size : Int32 size, skip(count : Int) skip, skip_while(& : T -> ) : Array(T) skip_while, sum(initial)
sum
sum(initial, & : T -> )
sum(& : T -> ) sum
, take_while(& : T -> ) : Array(T) take_while, tally : Hash(T, Int32) tally, tally_by(& : T -> U) : Hash(U, Int32) forall U tally_by, to_a to_a, to_h
to_h(& : T -> Tuple(K, V)) forall K, V to_h
, to_set : Set(T) to_set, zip(*others : Indexable | Iterable | Iterator, &)
zip(*others : Indexable | Iterable | Iterator) zip
, zip?(*others : Indexable | Iterable | Iterator, &)
zip?(*others : Indexable | Iterable | Iterator) zip?

Class methods inherited from module Enumerable(T)

element_type(x) element_type

Instance methods inherited from module Iterable(T)

chunk(reuse = false, &block : T -> U) forall U chunk, chunk_while(reuse : Bool | Array(T) = false, &block : T, T -> B) forall B chunk_while, cycle(n)
cycle cycle
, each each, each_cons(count : Int, reuse = false) each_cons, each_slice(count : Int, reuse = false) each_slice, each_with_index(offset = 0) each_with_index, each_with_object(obj) each_with_object, slice_after(reuse : Bool | Array(T) = false, &block : T -> B) forall B
slice_after(pattern, reuse : Bool | Array(T) = false) slice_after
, slice_before(reuse : Bool | Array(T) = false, &block : T -> B) forall B
slice_before(pattern, reuse : Bool | Array(T) = false) slice_before
, slice_when(reuse : Bool | Array(T) = false, &block : T, T -> B) forall B slice_when

Instance methods inherited from struct Value

==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==
, dup dup

Instance methods inherited from class Object

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===
, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash
, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?
, inspect(io : IO) : Nil
inspect : String inspect
, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json
, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json
, to_s(io : IO) : Nil
to_s : String to_s
, to_yaml(io : IO) : Nil
to_yaml : String to_yaml
, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Class methods inherited from class Object

from_json(string_or_io, root : String)
from_json(string_or_io) from_json
, from_yaml(string_or_io : String | IO) from_yaml

Constructor Detail

def self.new(& : Int32 -> T)Source

Creates a new static array and invokes the block once for each index of the array, assigning the block's value in that index.

StaticArray(Int32, 3).new { |i| i * 2 } # => StaticArray[0, 2, 4]

def self.new(value : T)Source

Creates a new static array filled with the given value.

StaticArray(Int32, 3).new(42) # => StaticArray[42, 42, 42]

Instance Method Detail

def ==(other : StaticArray)Source

Equality. Returns true if each element in self is equal to each corresponding element in other.

array = StaticArray(Int32, 3).new 0  # => StaticArray[0, 0, 0]
array2 = StaticArray(Int32, 3).new 0 # => StaticArray[0, 0, 0]
array3 = StaticArray(Int32, 3).new 1 # => StaticArray[1, 1, 1]
array == array2                      # => true
array == array3                      # => false

def ==(other)Source

Equality with another object. Always returns false.

array = StaticArray(Int32, 3).new 0 # => StaticArray[0, 0, 0]
array == nil                        # => false

def cloneSource

Returns a new StaticArray where each element is cloned from elements in self.

def fill(value : T) : selfSource

Replaces every element in self with the given value. Returns self.

array = [1, 2, 3, 4]
array.fill(2) # => [2, 2, 2, 2]
array         # => [2, 2, 2, 2]

def index(object, offset : Int = 0)Source

Description copied from module Indexable(T)

Returns the index of the first appearance of value in self starting from the given offset, or nil if the value is not in self.

[1, 2, 3, 1, 2, 3].index(2, offset: 2) # => 4

def map(&block : T -> U) : StaticArray(U, N) forall USource

Returns a new static array where elements are mapped by the given block.

array = StaticArray[1, 2.5, "a"]
array.map &.to_s # => StaticArray["1", "2.5", "a"]

def map_with_index(offset = 0, &block : T, Int32 -> U) : StaticArray(U, N) forall USource

Like #map, but the block gets passed both the element and its index.

Accepts an optional offset parameter, which tells it to start counting from there.

def pretty_print(pp)Source

def rotate!(n : Int = 1) : selfSource

Shifts all elements of self to the left n times. Returns self.

a1 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
a2 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
a3 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

a1.rotate!
a2.rotate!(1)
a3.rotate!(3)

a1 # => [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
a2 # => [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
a3 # => [3, 4, 5, 6, 7, 8, 9, 0, 1, 2]

def size : Int32Source

Returns the size of self

array = StaticArray(Int32, 3).new { |i| i + 1 }
array.size # => 3

def to_s(io : IO) : NilSource

Appends a string representation of this static array to the given IO.

array = StaticArray(Int32, 3).new { |i| i + 1 }
array.to_s # => "StaticArray[1, 2, 3]"

def to_slice : Slice(T)Source

Returns a slice that points to the elements of this static array. Changes made to the returned slice also affect this static array.

array = StaticArray(Int32, 3).new(2)
slice = array.to_slice # => Slice[2, 2, 2]
slice[0] = 3
array # => StaticArray[3, 2, 2]

def to_unsafe : Pointer(T)Source

Returns a pointer to this static array's data.

ary = StaticArray(Int32, 3).new(42)
ary.to_unsafe[0] # => 42

def unsafe_fetch(index : Int) : TSource

Description copied from module Indexable(T)

Returns the element at the given index, without doing any bounds check.

Indexable makes sure to invoke this method with index in 0...size, so converting negative indices to positive ones is not needed here.

Clients never invoke this method directly. Instead, they access elements with #[](index) and #[]?(index).

This method should only be directly invoked if you are absolutely sure the index is in bounds, to avoid a bounds check for a small boost of performance.

def unsafe_put(index : Int, value : T)Source

Description copied from module Indexable::Mutable(T)

Sets the element at the given index to value, without doing any bounds check.

Indexable::Mutable makes sure to invoke this method with index in 0...size, so converting negative indices to positive ones is not needed here.

Clients never invoke this method directly. Instead, they modify elements with #[]=(index, value).

This method should only be directly invoked if you are absolutely sure the index is in bounds, to avoid a bounds check for a small boost of performance.

Macro Detail

macro [](*args)Source

Creates a new StaticArray with the given args. The type of the static array will be the union of the type of the given args, and its size will be the number of elements in args.

ary = StaticArray[1, 'a']
ary[0]    # => 1
ary[1]    # => 'a'
ary.class # => StaticArray(Char | Int32, 2)

See also: Number.static_array.

© 2012–2021 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/1.2.1/StaticArray.html