Iterable

A collection of functions to manipulate Iterable

@example

const iterable = Iterable.create(() => ({
  next() { ... }
}));

const iterable = Iterable.create(function* () { ... })

Index

Accessor

• size

Constructor

• create
• empty
• from
• generate
• of

Predicate

• every
• some

Type

• hasInstance

Other

• chunks
• concat
• drop
• filter
• find
• flatMap
• map
• reduce
• take
• zip

Accessor

size

• size<Value>(self: Iterable<Value, any, any>): Int

• Returns the size of iterable

  @example

  const iterable = Iterable.of(1, 2, 3);
  size(iterable); // 3

  ---

  Type parameters

  • Value

Constructor

create

• create<Value>(iteratorFn: () => Iterator<Value, any, any>): Iterable<Value>

• Iterable constructor

  @example

  const iterable = Iterable.create(() => ({
    next() { ... }
  }))

  ---

  Type parameters

  • Value

empty

• empty<Value>(): Iterable<Value>

• Returns an iterable that have no value

  @example

  Array.from(Iterable.empty()) // == []

  ---

  Type parameters

  • Value = never

from

• from<Value>(source: Iterable<Value, any, any> | () => Iterator<Value, any, any>): Iterable<Value>

• @example

  Iterable.from([1, 2, 3]);// Iterable.of(1, 2, 3)
  Iterable.from(function* () { yield 1; yield 2; yield 3; })// Iterable.of(1, 2, 3)

  ---

  Type parameters

  • Value

generate

• generate<Value>(length: number, mapFn: (index: Int) => Value): Iterable<Value>

• Generate an iterable of length using mapFn(index) on each element

  @example

  Iterable.generate(3, () => 'a');// == Iterable.of('a', 'a', 'a')
  Iterable.generate(3, (index) => index * 2);// == Iterable.of(0, 2, 4)

  ---

  Type parameters

  • Value

of

• of<Value>(...values: Value[]): Iterable<Value>

• Create an iterable of given values

  @example

  Iterable.of('a', 'b', 'c');// 'a', 'b', 'c'

  ---

  Type parameters

  • Value

Predicate

every

• every<Value>(self: Iterable<Value, any, any>, predicate: (currentValue: Value, currentIndex: Int) => boolean): boolean

• Tests whether all elements in the iterable pass the test implemented by the provided function.

  @example

  const iterable = Iterable.of(1, 2, 3);
  Iterable.every(iterable, (currentValue) => currentValue >= 1); // true
  Iterable.every(iterable, (currentValue) => currentValue >= 2); // false
  Iterable.every(iterable, (currentValue) => currentValue < 0); // false

  ---

  Type parameters

  • Value

some

• some<Value>(self: Iterable<Value, any, any>, predicate: (currentValue: Value, currentIndex: Int) => boolean): boolean

• Tests whether any element in the iterable pass the test implemented by the provided function.

  @example

  const iterable = Iterable.of(1, 2, 3);
  Iterable.some(iterable, (currentValue) => currentValue >= 1); // true
  Iterable.some(iterable, (currentValue) => currentValue >= 2); // true
  Iterable.some(iterable, (currentValue) => currentValue < 0); // false

  ---

  Type parameters

  • Value

Type

hasInstance

• hasInstance(anyValue: unknown): anyValue is Iterable<unknown, any, any>

• Returns true if anyValue is a valid Iterable

  @example

  Iterable.hasInstance({});// false
  Iterable.hasInstance([]);// true
  Iterable.hasInstance({ [Symbol.iterator]: () => ({ next: () => ({ done: true }) }) });// true

Other

chunks

• chunks<Value>(self: Iterable<Value, any, any>, chunkSize: number): Iterable<Value[]>

• Splits an iterable into chunks of a specified size

  @example

  const chunks = Iterable.chunks([1, 2, 3, 4, 5], 2); // == Iterable.of([1, 2], [3, 4], [5])

  ---

  Type parameters

  • Value

concat

• concat<Value>(iterables: Iterable<Iterable<Value, any, any>, any, any>): Iterable<Value>

• Concatenates multiple iterables into a single iterable

  @example

  const iterable = Iterable.of(
    Iterable.of(1, 2),
    Iterable.of(3, 4),
  );
  Iterable.concat(iterable); // == Iterable.of(1, 2, 3, 4)

  ---

  Type parameters

  • Value

drop

• drop<Value>(self: Iterable<Value, any, any>, limit: number): Iterable<Value>

• Skips the given number of elements at the start of this iterator.

  @example

  const iterable = Iterable.of(1, 2, 3);
  Iterable.drop(iterable, 1); // == Iterable.of(2, 3)

  ---

  Type parameters

  • Value

filter

• filter<Value>(self: Iterable<Value, any, any>, predicate: (currentValue: Value, currentIndex: Int) => boolean): Iterable<Value>

• Return a new iterable that filters values using predicate

  @example

  const iterable = [1, 2, 3];
  Iterable.filter(
    iterable,
    (currentValue, currentIndex) => currentValue > 1,
  );// == Iterable.of(2, 3)

  ---

  Type parameters

  • Value

find

• find<Value>(self: Iterable<Value, any, any>, predicate: (currentValue: Value, currentIndex: number) => boolean): Option<Value>

• Returns the first element for which the given function returns true, otherwise undefined.

  @example

  const iterable = Iterable.of(
    { name: 'amy', id: 1 },
    { name: 'bob', id: 2 }
  );
  find(iterable, (item) => item.name === 'bob') // { name: 'bob', id: 2 }
  find(iterable, (item) => item.name === 'cat') // undefined

  ---

  Type parameters

  • Value

flatMap

• flatMap<ValueFrom, ValueTo>(self: Iterable<ValueFrom, any, any>, mapFn: (currentValue: ValueFrom, currentIndex: Int) => Iterable<ValueTo, any, any>): Iterable<ValueTo>

• Return a new Iterable which applies mapFn and concatenate the result to the previous

  @example

  const iterable = Iterable.of(1, 2, 3);
  Iterable.flatMap(
    iterable,
    (currentValue, currentIndex) => Iterable.of(currentValue, currentValue * 2),
  );// == Iterable.of(1, 2, 2, 4, 3, 6)

  ---

  Type parameters

  • ValueFrom
  • ValueTo

map

• map<ValueFrom, ValueTo>(self: Iterable<ValueFrom, any, any>, mapFn: (currentValue: ValueFrom, currentIndex: Int) => ValueTo): Iterable<ValueTo>

• Return a new Iterable which applies mapFn to each values

  @example

  const iterable = [1, 2, 3];
  Iterable.map(
    iterable,
    (currentValue, currentIndex) => currentValue * 2,
  );// == Iterable.of(2, 4, 6)

  ---

  Type parameters

  • ValueFrom
  • ValueTo

reduce

• reduce<Value, Return>(self: Iterable<Value, any, any>, reducer: (accumulator: Return, currentValue: Value, currentIndex: Int) => Return, initialValue: Return): Return

• Reduce an initialValue to the reducer function

  @example

  const iterable = [1, 2, 3];
  Iterable.reduce(iterable, (total, currentValue, currentIndex) => total + value, 0);// 6

  ---

  Type parameters

  • Value
  • Return

take

• take<Value>(self: Iterable<Value, any, any>, limit: number): Iterable<Value>

• Take a specified number of elements from an iterable.

  @example

  const iterable = Iterable.of(1, 2, 3);
  Iterable.take(iterable, 2); // == Iterable.of(1, 2)

  ---

  Type parameters

  • Value

zip

• zip<L, R>(left: Iterable<L, any, any>, right: Iterable<R, any, any>): Iterable<[L, R]>

• Combine two iterables into an iterable of couple of their values. The result has the size of the smallest iterable used.

  @example

  const left = [1, 2, 3];
  const right = ['a', 'b'];
  Iterable.zip(left, right);// == Iterable.of([1, 'a'], [2, 'b'])

  ---

  Type parameters

  • L
  • R