@esfx/iter-fn Package

An iteration and query API for ECMAScript iterables.

Installation

npm i @esfx/iter-fn

Usage

import { map } from "@esfx/iter-fn";
const x = map([1, 2, 3], x => x * 2);
x; // [2, 4, 6]

Interfaces

ConsumeOptions

Functions

ancestors(source, predicate)

Selects the ancestors of each node in the iterable. This is equivalent to the ancestor::* selector in XPath. Hierarchy

Declaration
export declare function ancestors<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

ancestors(source, predicate)

Declaration
export declare function ancestors<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

ancestorsAndSelf(source, predicate)

Selects the ancestors of each node in the iterable, along with the node itself. This is equivalent to the ancestor-or-self::* selector in XPath. Hierarchy

Declaration
export declare function ancestorsAndSelf<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

ancestorsAndSelf(source, predicate)

Declaration
export declare function ancestorsAndSelf<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

append(source, value)

Creates an Iterable for the elements of source with the provided value appended to the end.

Declaration
export declare function append<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, value: T): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

The Iterable to append to.

value
T

The value to append. Subquery

Returns

append(source, value)

Creates an Iterable for the elements of source with the provided value appended to the end.

Declaration
export declare function append<T>(source: Iterable<T>, value: T): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

The Iterable to append to.

value
T

The value to append. Subquery

Returns

average(source)

Computes the average for a series of numbers.

Declaration
export declare function average(source: Iterable<number>): number;
Parameters
source
Iterable<number>

An Iterable object. Scalar

Returns

average(source, elementSelector)

Computes the average for a series of numbers.

Declaration
export declare function average<T>(source: Iterable<T>, elementSelector: (element: T) => number): number;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

elementSelector
(element: T) => number

A callback used to convert a value in source to a number. Scalar

Returns

bottomMost(source, predicate, equaler)

Creates a HierarchyIterable for the bottom-most elements of a HierarchyIterable. Elements of source that are an ancestor of any other element of source are removed.

Declaration
export declare function bottomMost<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (value: T) => value is U, equaler?: Equaler<TNode>): HierarchyIterable<TNode, U>;
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

A HierarchyIterable object.

predicate
(value: T) => value is U

An optional callback used to filter the results. Hierarchy

equaler
Equaler<TNode>

Returns

bottomMost(source, predicate, equaler)

Creates a HierarchyIterable for the bottom-most elements of a HierarchyIterable. Elements of source that are an ancestor of any other element of source are removed.

Declaration
export declare function bottomMost<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate?: (value: T) => boolean, equaler?: Equaler<TNode>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

A HierarchyIterable object.

predicate
(value: T) => boolean

An optional callback used to filter the results.

equaler
Equaler<TNode>

An optional Equaler used to compare equality between nodes. Hierarchy

Returns

children(source, predicate)

Selects the children of each node in the iterable. This is equivalent to the child::* selector in XPath, or the > combinator in CSS. Hierarchy

Declaration
export declare function children<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

children(source, predicate)

Declaration
export declare function children<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

concat(left, right)

Creates an Iterable that concatenates two Iterable objects.

Declaration
export declare function concat<TNode, T extends TNode>(left: HierarchyIterable<TNode, T>, right: Iterable<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
HierarchyIterable<TNode, T>

An Iterable object.

right
Iterable<T>

An Iterable object. Subquery

Returns

concat(left, right)

Creates an Iterable that concatenates two Iterable objects.

Declaration
export declare function concat<TNode, T extends TNode>(left: Iterable<T>, right: HierarchyIterable<TNode, T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
Iterable<T>

An Iterable object.

right
HierarchyIterable<TNode, T>

An Iterable object. Subquery

Returns

concat(left, right)

Creates an Iterable that concatenates two Iterable objects.

Declaration
export declare function concat<T>(left: Iterable<T>, right: Iterable<T>): Iterable<T>;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object. Subquery

Returns

consume(iterator, options)

Creates an Iterable that, when iterated, consumes the provided Iterator.

Declaration
export declare function consume<T>(iterator: Iterator<T>, options?: ConsumeOptions): Iterable<T>;
Type Parameters
T

Parameters
iterator
Iterator<T>

An Iterator object. Query

options
ConsumeOptions

Returns

continuous(value)

Creates an Iterable that repeats the provided value forever.

Declaration
export declare function continuous<T>(value: T): Iterable<T>;
Type Parameters
T

Parameters
value
T

The value for each element of the Iterable. Query

Returns

copyTo(source, collection, start, count)

Writes each element of a source iterable to a destination. The destination must already have enough space to write the requested number of elements (i.e. arrays are *not* resized).

Declaration
export declare function copyTo<T, U extends IndexedCollection<T> | T[]>(source: Iterable<T>, collection: U, start?: number, count?: number): U;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

collection
U

The destination array or IndexedCollection.

start
number

The offset into the array at which to start writing.

count
number

The number of elements to write to the array. Scalar

Returns
U

corresponds(left, right, equaler)

Computes a scalar value indicating whether every element in left corresponds to a matching element in right at the same position.

Declaration
export declare function corresponds<T>(left: Iterable<T>, right: Iterable<T>, equaler?: EqualityComparison<T> | Equaler<T>): boolean;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
EqualityComparison<T> | Equaler<T>

An optional callback used to compare the equality of two elements. Scalar

Returns

corresponds(left, right, equaler)

Computes a scalar value indicating whether every element in left corresponds to a matching element in right at the same position.

Declaration
export declare function corresponds<T, U>(left: Iterable<T>, right: Iterable<U>, equaler: (left: T, right: U) => boolean): boolean;
Type Parameters
T

U

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<U>

An Iterable object.

equaler
(left: T, right: U) => boolean

An optional callback used to compare the equality of two elements. Scalar

Returns

correspondsBy(left, right, keySelector, keyEqualer)

Computes a scalar value indicating whether the key for every element in left corresponds to a matching key in right at the same position.

Declaration
export declare function correspondsBy<T, K>(left: Iterable<T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): boolean;
Type Parameters
T

K

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element. Scalar

keyEqualer
Equaler<K>

Returns

correspondsBy(left, right, leftKeySelector, rightKeySelector, keyEqualer)

Computes a scalar value indicating whether the key for every element in left corresponds to a matching key in right at the same position.

Declaration
export declare function correspondsBy<T, U, K>(left: Iterable<T>, right: Iterable<U>, leftKeySelector: (element: T) => K, rightKeySelector: (element: U) => K, keyEqualer?: EqualityComparison<K> | Equaler<K>): boolean;
Type Parameters
T

U

K

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<U>

An Iterable object.

leftKeySelector
(element: T) => K

A callback used to select the key for each element in left.

rightKeySelector
(element: U) => K

A callback used to select the key for each element in right.

keyEqualer
EqualityComparison<K> | Equaler<K>

An optional callback used to compare the equality of two keys. Scalar

Returns

count(source, predicate)

Counts the number of elements, optionally filtering elements using the supplied callback.

Declaration
export declare function count<T>(source: Iterable<T>, predicate?: (element: T) => boolean): number;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

An optional callback used to match each element. Scalar

Returns

defaultIfEmpty(source, defaultValue)

Creates an Iterable that contains the provided default value if source contains no elements.

Declaration
export declare function defaultIfEmpty<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, defaultValue: T): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

defaultValue
T

The default value. Subquery

Returns

defaultIfEmpty(source, defaultValue)

Creates an Iterable that contains the provided default value if source contains no elements.

Declaration
export declare function defaultIfEmpty<T>(source: Iterable<T>, defaultValue: T): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

defaultValue
T

The default value. Subquery

Returns

descendants(source, predicate)

Selects the descendents of each node in the iterable. This is equivalent to the descendant::* selector in XPath, or the (space) combinator in CSS. Hierarchy

Declaration
export declare function descendants<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

descendants(source, predicate)

Declaration
export declare function descendants<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

descendantsAndSelf(source, predicate)

Selects the descendents of each node in the iterable, along with the node itself. This is equivalent to the descendant-or-self::* selector in XPath. Hierarchy

Declaration
export declare function descendantsAndSelf<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

descendantsAndSelf(source, predicate)

Declaration
export declare function descendantsAndSelf<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

distinct(source, keyEqualer)

Creates an Iterable for the distinct elements of source. Subquery

Declaration
export declare function distinct<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keyEqualer
Equaler<K>

Returns

distinct(source, equaler)

Creates an Iterable for the distinct elements of source. Subquery

Declaration
export declare function distinct<T>(source: Iterable<T>, equaler?: Equaler<T>): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare element equality.

Returns

distinctBy(source, keySelector, keyEqualer)

Creates an Iterable for the distinct elements of source. Subquery

Declaration
export declare function distinctBy<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (value: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(value: T) => K

A callback used to select the key to determine uniqueness.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality.

Returns

distinctBy(source, keySelector, keyEqualer)

Creates an Iterable for the distinct elements of source. Subquery

Declaration
export declare function distinctBy<T, K>(source: Iterable<T>, keySelector: (value: T) => K, keyEqualer?: Equaler<K>): Iterable<T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(value: T) => K

A callback used to select the key to determine uniqueness.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality.

Returns

drop(source, count)

Creates a subquery containing all elements except the first elements up to the supplied count.

Declaration
export declare function drop<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, count: number): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

count
number

The number of elements to skip. Subquery

Returns

drop(source, count)

Creates a subquery containing all elements except the first elements up to the supplied count.

Declaration
export declare function drop<T>(source: Iterable<T>, count: number): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

count
number

The number of elements to skip. Subquery

Returns

dropRight(source, count)

Creates a subquery containing all elements except the last elements up to the supplied count.

Declaration
export declare function dropRight<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, count: number): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

count
number

The number of elements to skip. Subquery

Returns

dropRight(source, count)

Creates a subquery containing all elements except the last elements up to the supplied count.

Declaration
export declare function dropRight<T>(source: Iterable<T>, count: number): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

count
number

The number of elements to skip. Subquery

Returns

dropUntil(source, predicate)

Creates a subquery containing all elements except the first elements that do not match the supplied predicate.

Declaration
export declare function dropUntil<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate: (element: T) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

dropUntil(source, predicate)

Creates a subquery containing all elements except the first elements that do not match the supplied predicate.

Declaration
export declare function dropUntil<T>(source: Iterable<T>, predicate: (element: T) => boolean): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

dropWhile(source, predicate)

Creates a subquery containing all elements except the first elements that match the supplied predicate.

Declaration
export declare function dropWhile<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate: (element: T) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

dropWhile(source, predicate)

Creates a subquery containing all elements except the first elements that match the supplied predicate.

Declaration
export declare function dropWhile<T>(source: Iterable<T>, predicate: (element: T) => boolean): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

elementAt(source, offset)

Finds the value at the provided offset. A negative offset starts from the last element.

Declaration
export declare function elementAt<T>(source: Iterable<T>, offset: number | Index): T | undefined;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

offset
number | Index

An offset. Scalar

Returns
T | undefined

empty()

Creates an Iterable with no elements. Query

Declaration
export declare function empty<T>(): Iterable<T>;
Type Parameters
T

Returns

endsWith(left, right, equaler)

Computes a scalar value indicating whether the elements of left end with the same sequence of elements in right.

Declaration
export declare function endsWith<T>(left: Iterable<T>, right: Iterable<T>, equaler?: EqualityComparison<T> | Equaler<T>): boolean;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
EqualityComparison<T> | Equaler<T>

An optional callback used to compare the equality of two elements. Scalar

Returns

endsWith(left, right, equaler)

Computes a scalar value indicating whether the elements of left end with the same sequence of elements in right.

Declaration
export declare function endsWith<T, U>(left: Iterable<T>, right: Iterable<U>, equaler: (left: T, right: U) => boolean): boolean;
Type Parameters
T

U

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<U>

An Iterable object.

equaler
(left: T, right: U) => boolean

An optional callback used to compare the equality of two elements. Scalar

Returns

every(source, predicate)

Computes a scalar value indicating whether all elements match the supplied callback.

Declaration
export declare function every<T, U extends T>(source: Iterable<T>, predicate: (element: T) => element is U): source is Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => element is U

A callback used to match each element. Scalar

Returns
source is Iterable<U>

every(source, predicate)

Computes a scalar value indicating whether all elements match the supplied callback.

Declaration
export declare function every<T>(source: Iterable<T>, predicate: (element: T) => boolean): boolean;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Scalar

Returns

except(left, right, equaler)

Creates an Iterable for the set difference between two Iterable objects.

Declaration
export declare function except<TNode, T extends TNode>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, equaler?: Equaler<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
HierarchyIterable<TNode, T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

except(left, right, equaler)

Creates an Iterable for the set difference between two Iterable objects.

Declaration
export declare function except<T>(left: Iterable<T>, right: Iterable<T>, equaler?: Equaler<T>): Iterable<T>;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

exceptBy(left, right, keySelector, keyEqualer)

Creates an Iterable for the set difference between two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function exceptBy<TNode, T extends TNode, K>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
left
HierarchyIterable<TNode, T>

An Iterable object.

right
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

exceptBy(left, right, keySelector, keyEqualer)

Creates an Iterable for the set difference between two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function exceptBy<T, K>(left: Iterable<T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<T>;
Type Parameters
T

K

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

exclude(source, values)

Creates an Iterable with every instance of the specified value removed.

Declaration
export declare function exclude<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, ...values: T[]): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

values
T[]

The values to exclude. Subquery

Returns

exclude(source, values)

Creates an Iterable with every instance of the specified value removed.

Declaration
export declare function exclude<T>(source: Iterable<T>, ...values: T[]): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

values
T[]

The values to exclude. Subquery

Returns

filter(source, predicate)

Creates an Iterable whose elements match the supplied predicate.

Declaration
export declare function filter<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (element: T, offset: number) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T, offset: number) => element is U

A callback used to match each element. Subquery

Returns

filter(source, predicate)

Creates an Iterable whose elements match the supplied predicate.

Declaration
export declare function filter<T, U extends T>(source: Iterable<T>, predicate: (element: T, offset: number) => element is U): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T, offset: number) => element is U

A callback used to match each element. Subquery

Returns

filter(source, predicate)

Creates an Iterable whose elements match the supplied predicate.

Declaration
export declare function filter<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate: (element: T, offset: number) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

A callback used to match each element. Subquery

Returns

filter(source, predicate)

Creates an Iterable whose elements match the supplied predicate.

Declaration
export declare function filter<T>(source: Iterable<T>, predicate: (element: T, offset: number) => boolean): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

A callback used to match each element. Subquery

Returns

filterBy(source, keySelector, predicate)

Creates an Iterable where the selected key for each element matches the supplied predicate.

Declaration
export declare function filterBy<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, predicate: (key: K, offset: number) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

predicate
(key: K, offset: number) => boolean

A callback used to match each key. Subquery

Returns

filterBy(source, keySelector, predicate)

Creates an Iterable where the selected key for each element matches the supplied predicate.

Declaration
export declare function filterBy<T, K>(source: Iterable<T>, keySelector: (element: T) => K, predicate: (key: K, offset: number) => boolean): Iterable<T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

predicate
(key: K, offset: number) => boolean

A callback used to match each key. Subquery

Returns

filterDefined(source)

Creates an Iterable whose elements are neither null nor undefined.

Declaration
export declare function filterDefined<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>): HierarchyIterable<TNode, NonNullable<T>>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object. Subquery

Returns
HierarchyIterable<TNode, NonNullable<T>>

filterDefined(source)

Creates an Iterable whose elements are neither null nor undefined.

Declaration
export declare function filterDefined<T>(source: Iterable<T>): Iterable<NonNullable<T>>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object. Subquery

Returns
Iterable<NonNullable<T>>

filterDefinedBy(source, keySelector)

Creates an Iterable where the selected key for each element is neither null nor undefined.

Declaration
export declare function filterDefinedBy<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (value: T) => K): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(value: T) => K

A callback used to select the key for each element. Subquery

Returns

filterDefinedBy(source, keySelector)

Creates an Iterable where the selected key for each element is neither null nor undefined.

Declaration
export declare function filterDefinedBy<T, K>(source: Iterable<T>, keySelector: (value: T) => K): Iterable<T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(value: T) => K

A callback used to select the key for each element. Subquery

Returns

filterNot(source, predicate)

Creates an Iterable whose elements do not match the supplied predicate.

Declaration
export declare function filterNot<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (element: T, offset: number) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T, offset: number) => element is U

A callback used to match each element. Subquery

Returns

filterNot(source, predicate)

Creates an Iterable whose elements do not match the supplied predicate.

Declaration
export declare function filterNot<T, U extends T>(source: Iterable<T>, predicate: (element: T, offset: number) => element is U): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T, offset: number) => element is U

A callback used to match each element. Subquery

Returns

filterNot(source, predicate)

Creates an Iterable whose elements do not match the supplied predicate.

Declaration
export declare function filterNot<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate: (element: T, offset: number) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

A callback used to match each element. Subquery

Returns

filterNot(source, predicate)

Creates an Iterable whose elements do not match the supplied predicate.

Declaration
export declare function filterNot<T>(source: Iterable<T>, predicate: (element: T, offset: number) => boolean): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

A callback used to match each element. Subquery

Returns

filterNotBy(source, keySelector, predicate)

Creates an Iterable where the selected key for each element does not match the supplied predicate.

Declaration
export declare function filterNotBy<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, predicate: (key: K, offset: number) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

predicate
(key: K, offset: number) => boolean

A callback used to match each key. Subquery

Returns

filterNotBy(source, keySelector, predicate)

Creates an Iterable where the selected key for each element does not match the supplied predicate.

Declaration
export declare function filterNotBy<T, K>(source: Iterable<T>, keySelector: (element: T) => K, predicate: (key: K, offset: number) => boolean): Iterable<T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

predicate
(key: K, offset: number) => boolean

A callback used to match each key. Subquery

Returns

filterNotDefinedBy(source, keySelector)

Creates an Iterable where the selected key for each element is either null or undefined.

Declaration
export declare function filterNotDefinedBy<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (value: T) => K): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(value: T) => K

A callback used to select the key for each element. Subquery

Returns

filterNotDefinedBy(source, keySelector)

Creates an Iterable where the selected key for each element is either null or undefined.

Declaration
export declare function filterNotDefinedBy<T, K>(source: Iterable<T>, keySelector: (value: T) => K): Iterable<T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(value: T) => K

A callback used to select the key for each element. Subquery

Returns

first(source, predicate)

Gets the first element, optionally filtering elements using the supplied callback.

Declaration
export declare function first<T, U extends T>(source: Iterable<T>, predicate: (element: T) => element is U): U | undefined;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => element is U

An optional callback used to match each element. Scalar

Returns
U | undefined

first(source, predicate)

Gets the first element, optionally filtering elements using the supplied callback.

Declaration
export declare function first<T>(source: Iterable<T>, predicate?: (element: T) => boolean): T | undefined;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

An optional callback used to match each element. Scalar

Returns
T | undefined

firstChild(source, predicate)

Selects the first child of each node in the iterable. This is equivalent to the child::*[first()] selector in XPath, or the :first-child pseudo class in CSS. Hierarchy

Declaration
export declare function firstChild<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

firstChild(source, predicate)

Declaration
export declare function firstChild<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

flatMap(source, projection)

Creates an Iterable that iterates the results of applying a callback to each element of source.

Declaration
export declare function flatMap<T, U>(source: Iterable<T>, projection: (element: T) => Iterable<U>): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

projection
(element: T) => Iterable<U>

A callback used to map each element into an iterable. Subquery

Returns

flatMap(source, projection, resultSelector)

Creates an Iterable that iterates the results of applying a callback to each element of source.

Declaration
export declare function flatMap<T, U, R>(source: Iterable<T>, projection: (element: T) => Iterable<U>, resultSelector: (element: T, innerElement: U) => R): Iterable<R>;
Type Parameters
T

U

R

Parameters
source
Iterable<T>

An Iterable object.

projection
(element: T) => Iterable<U>

A callback used to map each element into an iterable.

resultSelector
(element: T, innerElement: U) => R

A callback used to map an element and one of its projected values into a result. Subquery

Returns

following(source, predicate)

Selects the nodes that follow each node in the iterable. This is equivalent to the following-sibling::* selector in XPath or the ~ combinator in CSS. Hierarchy

Declaration
export declare function following<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

following(source, predicate)

Declaration
export declare function following<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

followingSiblings(source, predicate)

Selects the siblings that follow each node in the iterable. This is equivalent to the following-sibling::* selector in XPath or the ~ combinator in CSS. Hierarchy

Declaration
export declare function followingSiblings<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

followingSiblings(source, predicate)

Declaration
export declare function followingSiblings<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

forEach(source, callback)

Invokes a callback for each element of source.

Declaration
export declare function forEach<T>(source: Iterable<T>, callback: (element: T, offset: number) => void): void;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

callback
(element: T, offset: number) => void

The callback to invoke. Scalar

Returns
void

fullJoin(outer, inner, outerKeySelector, innerKeySelector, resultSelector, keyEqualer)

Creates an Iterable for the correlated elements between an outer Iterable object and an inner Iterable object.

Declaration
export declare function fullJoin<O, I, K, R>(outer: Iterable<O>, inner: Iterable<I>, outerKeySelector: (element: O) => K, innerKeySelector: (element: I) => K, resultSelector: (outer: O | undefined, inner: I | undefined) => R, keyEqualer?: Equaler<K>): Iterable<R>;
Type Parameters
O

I

K

R

Parameters
outer
Iterable<O>

An Iterable object.

inner
Iterable<I>

An Iterable object.

outerKeySelector
(element: O) => K

A callback used to select the key for an element in outer.

innerKeySelector
(element: I) => K

A callback used to select the key for an element in inner.

resultSelector
(outer: O | undefined, inner: I | undefined) => R

A callback used to select the result for the correlated elements.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Join

Returns

generate(count, generator)

Creates an Iterable whose values are provided by a callback executed a provided number of times.

Declaration
export declare function generate<T>(count: number, generator: (offset: number) => T): Iterable<T>;
Type Parameters
T

Parameters
count
number

The number of times to execute the callback.

generator
(offset: number) => T

The callback to execute. Query

Returns

groupBy(source, keySelector, keyEqualer)

Groups each element of an Iterable by its key.

Declaration
export declare function groupBy<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<HierarchyGrouping<K, TNode, T>>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

groupBy(source, keySelector, elementSelector, resultSelector, keyEqualer)

Groups each element of an Iterable by its key.

Declaration
export declare function groupBy<TNode, T extends TNode, K, R>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, elementSelector: undefined, resultSelector: (key: K, elements: HierarchyIterable<TNode, T>) => R, keyEqualer?: Equaler<K>): Iterable<R>;
Type Parameters
TNode

T

K

R

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

elementSelector
undefined

A callback used to select a value for an element.

resultSelector
(key: K, elements: HierarchyIterable<TNode, T>) => R

A callback used to select a result from a group.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

groupBy(source, keySelector, keyEqualer)

Groups each element of an Iterable by its key.

Declaration
export declare function groupBy<T, K>(source: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<Grouping<K, T>>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

groupBy(source, keySelector, elementSelector, keyEqualer)

Groups each element of an Iterable by its key.

Declaration
export declare function groupBy<T, K, V>(source: Iterable<T>, keySelector: (element: T) => K, elementSelector: (element: T) => V, keyEqualer?: Equaler<K>): Iterable<Grouping<K, V>>;
Type Parameters
T

K

V

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

elementSelector
(element: T) => V

A callback used to select a value for an element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

groupBy(source, keySelector, elementSelector, resultSelector, keyEqualer)

Groups each element of an Iterable by its key.

Declaration
export declare function groupBy<T, K, V, R>(source: Iterable<T>, keySelector: (element: T) => K, elementSelector: (element: T) => V, resultSelector: (key: K, elements: Iterable<V>) => R, keyEqualer?: Equaler<K>): Iterable<R>;
Type Parameters
T

K

V

R

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

elementSelector
(element: T) => V

A callback used to select a value for an element.

resultSelector
(key: K, elements: Iterable<V>) => R

A callback used to select a result from a group.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

groupJoin(outer, inner, outerKeySelector, innerKeySelector, resultSelector, keyEqualer)

Creates a grouped Iterable for the correlated elements between an outer Iterable object and an inner Iterable object.

Declaration
export declare function groupJoin<O, I, K, R>(outer: Iterable<O>, inner: Iterable<I>, outerKeySelector: (element: O) => K, innerKeySelector: (element: I) => K, resultSelector: (outer: O, inner: Iterable<I>) => R, keyEqualer?: Equaler<K>): Iterable<R>;
Type Parameters
O

I

K

R

Parameters
outer
Iterable<O>

An Iterable object.

inner
Iterable<I>

An Iterable object.

outerKeySelector
(element: O) => K

A callback used to select the key for an element in outer.

innerKeySelector
(element: I) => K

A callback used to select the key for an element in inner.

resultSelector
(outer: O, inner: Iterable<I>) => R

A callback used to select the result for the correlated elements.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Join

Returns

includes(source, value, equaler)

Computes a scalar value indicating whether the provided value is included in an Iterable.

Declaration
export declare function includes<T>(source: Iterable<T>, value: T, equaler?: EqualityComparison<T> | Equaler<T>): boolean;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

value
T

A value.

equaler
EqualityComparison<T> | Equaler<T>

An optional callback used to compare the equality of two elements. Scalar

Returns

includes(source, value, equaler)

Computes a scalar value indicating whether the provided value is included in an Iterable.

Declaration
export declare function includes<T, U>(source: Iterable<T>, value: U, equaler: (left: T, right: U) => boolean): boolean;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

value
U

A value.

equaler
(left: T, right: U) => boolean

An optional callback used to compare the equality of two elements. Scalar

Returns

includesSequence(left, right, equaler)

Computes a scalar value indicating whether the elements of left include an exact sequence of elements from right.

Declaration
export declare function includesSequence<T>(left: Iterable<T>, right: Iterable<T>, equaler?: EqualityComparison<T> | Equaler<T>): boolean;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
EqualityComparison<T> | Equaler<T>

A callback used to compare the equality of two elements. Scalar

Returns

includesSequence(left, right, equaler)

Computes a scalar value indicating whether the elements of left include an exact sequence of elements from right.

Declaration
export declare function includesSequence<T, U>(left: Iterable<T>, right: Iterable<U>, equaler: (left: T, right: U) => boolean): boolean;
Type Parameters
T

U

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<U>

An Iterable object.

equaler
(left: T, right: U) => boolean

A callback used to compare the equality of two elements. Scalar

Returns

intersect(left, right, equaler)

Creates an Iterable for the set intersection of two Iterable objects.

Declaration
export declare function intersect<TNode, T extends TNode>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, equaler?: Equaler<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
HierarchyIterable<TNode, T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

intersect(left, right, equaler)

Creates an Iterable for the set intersection of two Iterable objects.

Declaration
export declare function intersect<TNode, T extends TNode>(left: Iterable<T>, right: HierarchyIterable<TNode, T>, equaler?: Equaler<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
Iterable<T>

An Iterable object.

right
HierarchyIterable<TNode, T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

intersect(left, right, equaler)

Creates an Iterable for the set intersection of two Iterable objects.

Declaration
export declare function intersect<T>(left: Iterable<T>, right: Iterable<T>, equaler?: Equaler<T>): Iterable<T>;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

intersectBy(left, right, keySelector, keyEqualer)

Creates an Iterable for the set intersection of two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function intersectBy<TNode, T extends TNode, K>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
left
HierarchyIterable<TNode, T>

An Iterable object.

right
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

intersectBy(left, right, keySelector, keyEqualer)

Creates an Iterable for the set intersection of two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function intersectBy<TNode, T extends TNode, K>(left: Iterable<T>, right: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
left
Iterable<T>

An Iterable object.

right
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

intersectBy(left, right, keySelector, keyEqualer)

Creates an Iterable for the set intersection of two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function intersectBy<T, K>(left: Iterable<T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<T>;
Type Parameters
T

K

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

into(source, callback)

Pass the entire source to the provided callback, returning a scalar result. Useful as the last step in a query.

Declaration
export declare function into<T, S extends Iterable<T>, R>(source: S, callback: (source: S) => R): R;
Type Parameters
T

S

R

Parameters
source
S

An Iterable object.

callback
(source: S) => R

A callback function. Subquery

Returns
R

join(outer, inner, outerKeySelector, innerKeySelector, resultSelector, keyEqualer)

Creates an Iterable for the correlated elements of two Iterable objects.

Declaration
export declare function join<O, I, K, R>(outer: Iterable<O>, inner: Iterable<I>, outerKeySelector: (element: O) => K, innerKeySelector: (element: I) => K, resultSelector: (outer: O, inner: I) => R, keyEqualer?: Equaler<K>): Iterable<R>;
Type Parameters
O

I

K

R

Parameters
outer
Iterable<O>

An Iterable object.

inner
Iterable<I>

An Iterable object.

outerKeySelector
(element: O) => K

A callback used to select the key for an element in outer.

innerKeySelector
(element: I) => K

A callback used to select the key for an element in inner.

resultSelector
(outer: O, inner: I) => R

A callback used to select the result for the correlated elements.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Join

Returns

last(source, predicate)

Gets the last element of a Iterable, optionally filtering elements using the supplied callback.

Declaration
export declare function last<T, U extends T>(source: Iterable<T>, predicate: (element: T) => element is U): U | undefined;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => element is U

An optional callback used to match each element. Scalar

Returns
U | undefined

last(source, predicate)

Gets the last element of a Iterable, optionally filtering elements using the supplied callback.

Declaration
export declare function last<T>(source: Iterable<T>, predicate?: (element: T) => boolean): T | undefined;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

An optional callback used to match each element. Scalar

Returns
T | undefined

lastChild(source, predicate)

Selects the last child of each node in the iterable. This is equivalent to the child::*[last()] selector in XPath, or the :last-child pseudo class in CSS. Hierarchy

Declaration
export declare function lastChild<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

lastChild(source, predicate)

Declaration
export declare function lastChild<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

map(source, selector)

Creates an Iterable by applying a callback to each element of a Iterable.

Declaration
export declare function map<T, U>(source: Iterable<T>, selector: (element: T, offset: number) => U): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

selector
(element: T, offset: number) => U

A callback used to map each element. Subquery

Returns

materialize(source)

Eagerly evaluate the Iterable, returning a new Iterable. Subquery

Declaration
export declare function materialize<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

Returns

materialize(source)

Declaration
export declare function materialize<T>(source: Iterable<T>): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

Returns

max(source, comparer)

Gets the maximum element of a Iterable, optionally comparing elements using the supplied callback.

Declaration
export declare function max<T>(source: Iterable<T>, comparer?: Comparison<T> | Comparer<T>): T | undefined;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

comparer
Comparison<T> | Comparer<T>

An optional callback used to compare two elements. Scalar

Returns
T | undefined

maxBy(source, keySelector, keyComparer)

Gets the maximum element of a Iterable, optionally comparing the keys of each element using the supplied callback.

Declaration
export declare function maxBy<T, K>(source: Iterable<T>, keySelector: (value: T) => K, keyComparer?: Comparison<K> | Comparer<K>): T | undefined;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(value: T) => K

A callback used to choose the key to compare.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare the keys. Scalar

Returns
T | undefined

min(source, comparer)

Gets the minimum element of a Iterable, optionally comparing elements using the supplied callback.

Declaration
export declare function min<T>(source: Iterable<T>, comparer?: Comparison<T> | Comparer<T>): T | undefined;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

comparer
Comparison<T> | Comparer<T>

An optional callback used to compare two elements. Scalar

Returns
T | undefined

minBy(source, keySelector, keyComparer)

Gets the minimum element of a Iterable, optionally comparing the keys of each element using the supplied callback.

Declaration
export declare function minBy<T, K>(source: Iterable<T>, keySelector: (value: T) => K, keyComparer?: Comparison<K> | Comparer<K>): T | undefined;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(value: T) => K

A callback used to choose the key to compare.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare the keys. Scalar

Returns
T | undefined

nthChild(source, offset, predicate)

Creates a HierarchyIterable for the child of each element at the specified offset. A negative offset starts from the last child. This is equivalent to the :nth-child() pseudo-class in CSS.

Declaration
export declare function nthChild<TNode, U extends TNode>(source: HierarchyIterable<TNode>, offset: number, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

A HierarchyIterable object.

offset
number

The offset for the child.

predicate
(element: TNode) => element is U

An optional callback used to filter the results. Hierarchy

Returns

nthChild(source, offset, predicate)

Declaration
export declare function nthChild<TNode>(source: HierarchyIterable<TNode>, offset: number, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

offset
number

predicate
(element: TNode) => boolean

Returns

once(value)

Creates an Iterable over a single element.

Declaration
export declare function once<T>(value: T): Iterable<T>;
Type Parameters
T

Parameters
value
T

The only element for the Iterable. Query

Returns

orderBy(source, keySelector, keyComparer)

Creates an OrderedIterable whose elements are sorted in ascending order by the provided key.

Declaration
export declare function orderBy<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedHierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

orderBy(source, keySelector, keyComparer)

Creates an OrderedIterable whose elements are sorted in ascending order by the provided key.

Declaration
export declare function orderBy<T, K>(source: Iterable<T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedIterable<T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

orderByDescending(source, keySelector, keyComparer)

Creates an OrderedIterable whose elements are sorted in descending order by the provided key.

Declaration
export declare function orderByDescending<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedHierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

orderByDescending(source, keySelector, keyComparer)

Creates an OrderedIterable whose elements are sorted in descending order by the provided key.

Declaration
export declare function orderByDescending<T, K>(source: Iterable<T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedIterable<T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

pageBy(source, pageSize)

Creates an Iterable that splits an Iterable into one or more pages. While advancing from page to page is evaluated lazily, the elements of the page are evaluated eagerly.

Declaration
export declare function pageBy<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, pageSize: number): Iterable<HierarchyPage<TNode, T>>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

pageSize
number

The number of elements per page. Subquery

Returns

pageBy(source, pageSize, pageSelector)

Creates an Iterable that splits an Iterable into one or more pages. While advancing from page to page is evaluated lazily, the elements of the page are evaluated eagerly.

Declaration
export declare function pageBy<TNode, T extends TNode, R>(source: HierarchyIterable<TNode, T>, pageSize: number, pageSelector: (page: number, offset: number, values: HierarchyIterable<TNode, T>) => R): Iterable<R>;
Type Parameters
TNode

T

R

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

pageSize
number

The number of elements per page.

pageSelector
(page: number, offset: number, values: HierarchyIterable<TNode, T>) => R

A callback used to create a result for a page. Subquery

Returns

pageBy(source, pageSize)

Creates an Iterable that splits an Iterable into one or more pages. While advancing from page to page is evaluated lazily, the elements of the page are evaluated eagerly.

Declaration
export declare function pageBy<T>(source: Iterable<T>, pageSize: number): Iterable<Page<T>>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

pageSize
number

The number of elements per page. Subquery

Returns

pageBy(source, pageSize, pageSelector)

Creates an Iterable that splits an Iterable into one or more pages. While advancing from page to page is evaluated lazily, the elements of the page are evaluated eagerly.

Declaration
export declare function pageBy<T, R>(source: Iterable<T>, pageSize: number, pageSelector: (page: number, offset: number, values: Iterable<T>) => R): Iterable<R>;
Type Parameters
T

R

Parameters
source
Iterable<T>

An Iterable object.

pageSize
number

The number of elements per page.

pageSelector
(page: number, offset: number, values: Iterable<T>) => R

A callback used to create a result for a page. Subquery

Returns

parents(source, predicate)

Selects the parent of each node in the iterable. This is equivalent to the parent::* or .. selectors in XPath. Hierarchy

Declaration
export declare function parents<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

parents(source, predicate)

Declaration
export declare function parents<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

patch(source, start, skipCount, range)

Creates an Iterable for the elements of source with the provided range patched into the results.

Declaration
export declare function patch<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, start: number, skipCount?: number, range?: Iterable<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

The Iterable to patch.

start
number

The offset at which to patch the range.

skipCount
number

The number of elements to skip from start.

range
Iterable<T>

The range to patch into the result. Subquery

Returns

patch(source, start, skipCount, range)

Creates an Iterable for the elements of source with the provided range patched into the results.

Declaration
export declare function patch<T>(source: Iterable<T>, start: number, skipCount?: number, range?: Iterable<T>): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

The Iterable to patch.

start
number

The offset at which to patch the range.

skipCount
number

The number of elements to skip from start.

range
Iterable<T>

The range to patch into the result. Subquery

Returns

preceding(source, predicate)

Selects the nodes that precede each node in the iterable. This is equivalent to the preceding::** selector in XPath. Hierarchy

Declaration
export declare function preceding<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

preceding(source, predicate)

Declaration
export declare function preceding<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

precedingSiblings(source, predicate)

Selects the siblings that precede each node in the iterable. This is equivalent to the preceding-sibling::** selector in XPath. Hierarchy

Declaration
export declare function precedingSiblings<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

precedingSiblings(source, predicate)

Declaration
export declare function precedingSiblings<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

prepend(source, value)

Creates a subquery for the elements of the source with the provided value prepended to the beginning.

Declaration
export declare function prepend<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, value: T): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

value
T

The value to prepend. Subquery

Returns

prepend(source, value)

Creates a subquery for the elements of the source with the provided value prepended to the beginning.

Declaration
export declare function prepend<T>(source: Iterable<T>, value: T): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

value
T

The value to prepend. Subquery

Returns

range(start, end, increment)

Creates an Iterable over a range of numbers.

Declaration
export declare function range(start: number, end: number, increment?: number): Iterable<number>;
Parameters
start
number

The starting number of the range.

end
number

The ending number of the range.

increment
number

The amount by which to change between each itereated value. Query

Returns
Iterable<number>

reduce(source, accumulator)

Computes a scalar value by applying an accumulator callback over each element.

Declaration
export declare function reduce<T>(source: Iterable<T>, accumulator: (current: T, element: T, offset: number) => T): T;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: T, element: T, offset: number) => T

the callback used to compute the result. Scalar

Returns
T

reduce(source, accumulator, seed, resultSelector)

Computes a scalar value by applying an accumulator callback over each element.

Declaration
export declare function reduce<T, U>(source: Iterable<T>, accumulator: (current: U, element: T, offset: number) => U, seed: U, resultSelector?: (result: U, count: number) => U): U;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: U, element: T, offset: number) => U

the callback used to compute the result.

seed
U

An optional seed value. Scalar

resultSelector
(result: U, count: number) => U

Returns
U

reduce(source, accumulator, seed, resultSelector)

Computes a scalar value by applying an accumulator callback over each element.

Declaration
export declare function reduce<T, U, R>(source: Iterable<T>, accumulator: (current: U, element: T, offset: number) => U, seed: U, resultSelector: (result: U, count: number) => R): R;
Type Parameters
T

U

R

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: U, element: T, offset: number) => U

the callback used to compute the result.

seed
U

An optional seed value.

resultSelector
(result: U, count: number) => R

An optional callback used to compute the final result. Scalar

Returns
R

reduceRight(source, accumulator)

Computes a scalar value by applying an accumulator callback over each element in reverse.

Declaration
export declare function reduceRight<T>(source: Iterable<T>, accumulator: (current: T, element: T, offset: number) => T): T;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: T, element: T, offset: number) => T

the callback used to compute the result. Scalar

Returns
T

reduceRight(source, accumulator, seed, resultSelector)

Computes a scalar value by applying an accumulator callback over each element in reverse.

Declaration
export declare function reduceRight<T, U>(source: Iterable<T>, accumulator: (current: U, element: T, offset: number) => U, seed: U, resultSelector?: (result: U, count: number) => U): U;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: U, element: T, offset: number) => U

the callback used to compute the result.

seed
U

An optional seed value. Scalar

resultSelector
(result: U, count: number) => U

Returns
U

reduceRight(source, accumulator, seed, resultSelector)

Computes a scalar value by applying an accumulator callback over each element in reverse.

Declaration
export declare function reduceRight<T, U, R>(source: Iterable<T>, accumulator: (current: U, element: T, offset: number) => U, seed: U, resultSelector: (result: U, count: number) => R): R;
Type Parameters
T

U

R

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: U, element: T, offset: number) => U

the callback used to compute the result.

seed
U

An optional seed value.

resultSelector
(result: U, count: number) => R

An optional callback used to compute the final result. Scalar

Returns
R

repeat(value, count)

Creates an Iterable for a value repeated a provided number of times.

Declaration
export declare function repeat<T>(value: T, count: number): Iterable<T>;
Type Parameters
T

Parameters
value
T

The value for each element of the Iterable.

count
number

The number of times to repeat the value. Query

Returns

reverse(source)

Creates a subquery whose elements are in the reverse order. Ordering

Declaration
export declare function reverse<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

Returns

reverse(source)

Creates a subquery whose elements are in the reverse order. Ordering

Declaration
export declare function reverse<T>(source: Iterable<T>): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

Returns

root(source, predicate)

Selects the root element of each node in the iterable. This is equivalent to the / selector in XPath, or the :root selector in CSS. Hierarchy

Declaration
export declare function root<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

root(source, predicate)

Declaration
export declare function root<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

scan(source, accumulator)

Creates a subquery containing the cumulative results of applying the provided callback to each element.

Declaration
export declare function scan<T>(source: Iterable<T>, accumulator: (current: T, element: T, offset: number) => T): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: T, element: T, offset: number) => T

The callback used to compute each result. Subquery

Returns

scan(source, accumulator, seed)

Creates a subquery containing the cumulative results of applying the provided callback to each element.

Declaration
export declare function scan<T, U>(source: Iterable<T>, accumulator: (current: U, element: T, offset: number) => U, seed: U): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: U, element: T, offset: number) => U

The callback used to compute each result.

seed
U

An optional seed value. Subquery

Returns

scanRight(source, accumulator)

Creates a subquery containing the cumulative results of applying the provided callback to each element in reverse.

Declaration
export declare function scanRight<T>(source: Iterable<T>, accumulator: (current: T, element: T, offset: number) => T): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: T, element: T, offset: number) => T

The callback used to compute each result. Subquery

Returns

scanRight(source, accumulator, seed)

Creates a subquery containing the cumulative results of applying the provided callback to each element in reverse.

Declaration
export declare function scanRight<T, U>(source: Iterable<T>, accumulator: (current: U, element: T, offset: number) => U, seed: U): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

accumulator
(current: U, element: T, offset: number) => U

The callback used to compute each result.

seed
U

An optional seed value. Subquery

Returns

self(source, predicate)

Selects each node in the iterable. This is equivalent to the self::* or . selectors in XPath. Hierarchy

Declaration
export declare function self<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (element: T) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

predicate
(element: T) => element is U

Returns

self(source, predicate)

Declaration
export declare function self<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate?: (element: T) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

predicate
(element: T) => boolean

Returns

siblings(source, predicate)

Selects the siblings of each node in the iterable, excluding the node itself. Hierarchy

Declaration
export declare function siblings<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

siblings(source, predicate)

Declaration
export declare function siblings<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

siblingsAndSelf(source, predicate)

Selects the siblings of each node in the iterable, including the node itself. This equivalent to the ../* selector in XPath. Hierarchy

Declaration
export declare function siblingsAndSelf<TNode, U extends TNode>(source: HierarchyIterable<TNode>, predicate: (element: TNode) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

U

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => element is U

Returns

siblingsAndSelf(source, predicate)

Declaration
export declare function siblingsAndSelf<TNode>(source: HierarchyIterable<TNode>, predicate?: (element: TNode) => boolean): HierarchyIterable<TNode>;
Type Parameters
TNode

Parameters
source
HierarchyIterable<TNode>

predicate
(element: TNode) => boolean

Returns

single(source, predicate)

Gets the only element, or returns undefined.

Declaration
export declare function single<T, U extends T>(source: Iterable<T>, predicate: (element: T) => element is U): U | undefined;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => element is U

An optional callback used to match each element. Scalar

Returns
U | undefined

single(source, predicate)

Gets the only element, or returns undefined.

Declaration
export declare function single<T>(source: Iterable<T>, predicate?: (element: T) => boolean): T | undefined;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

An optional callback used to match each element. Scalar

Returns
T | undefined

some(source, predicate)

Computes a scalar value indicating whether source contains any elements, optionally filtering the elements using the supplied callback.

Declaration
export declare function some<T>(source: Iterable<T>, predicate?: (element: T) => boolean): boolean;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

An optional callback used to match each element. Scalar

Returns

span(source, predicate)

Creates a tuple whose first element is an Iterable containing the first span of elements that match the supplied predicate, and whose second element is an Iterable containing the remaining elements.

The first Iterable is eagerly evaluated, while the second Iterable is lazily evaluated.

Declaration
export declare function span<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (element: T, offset: number) => element is U): [HierarchyIterable<TNode, U>, HierarchyIterable<TNode, T>];
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T, offset: number) => element is U

The predicate used to match elements. Scalar

Returns
[HierarchyIterable<TNode, U>, HierarchyIterable<TNode, T>]

span(source, predicate)

Creates a tuple whose first element is an Iterable containing the first span of elements that match the supplied predicate, and whose second element is an Iterable containing the remaining elements.

The first Iterable is eagerly evaluated, while the second Iterable is lazily evaluated.

Declaration
export declare function span<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate: (element: T, offset: number) => boolean): [HierarchyIterable<TNode, T>, HierarchyIterable<TNode, T>];
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

The predicate used to match elements. Scalar

Returns
[HierarchyIterable<TNode, T>, HierarchyIterable<TNode, T>]

span(source, predicate)

Creates a tuple whose first element is an Iterable containing the first span of elements that match the supplied predicate, and whose second element is an Iterable containing the remaining elements.

The first Iterable is eagerly evaluated, while the second Iterable is lazily evaluated.

Declaration
export declare function span<T, U extends T>(source: Iterable<T>, predicate: (element: T, offset: number) => element is U): [Iterable<U>, Iterable<T>];
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T, offset: number) => element is U

The predicate used to match elements. Scalar

Returns

span(source, predicate)

Creates a tuple whose first element is an Iterable containing the first span of elements that match the supplied predicate, and whose second element is an Iterable containing the remaining elements.

The first Iterable is eagerly evaluated, while the second Iterable is lazily evaluated.

Declaration
export declare function span<T>(source: Iterable<T>, predicate: (element: T, offset: number) => boolean): [Iterable<T>, Iterable<T>];
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

The predicate used to match elements. Scalar

Returns

spanMap(source, keySelector, keyEqualer)

Creates a subquery whose elements are the contiguous ranges of elements that share the same key.

Declaration
export declare function spanMap<TNode, T extends TNode, K>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<HierarchyGrouping<K, TNode, T>>;
Type Parameters
TNode

T

K

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyEqualer
Equaler<K>

An Equaler used to compare key equality. Grouping

Returns

spanMap(source, keySelector, elementSelector, spanSelector, keyEqualer)

Creates a subquery whose elements are the contiguous ranges of elements that share the same key.

Declaration
export declare function spanMap<TNode, T extends TNode, K, R>(source: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, elementSelector: undefined, spanSelector: (key: K, elements: HierarchyIterable<TNode, T>) => R, keyEqualer?: Equaler<K>): Iterable<R>;
Type Parameters
TNode

T

K

R

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

elementSelector
undefined

A callback used to select a value for an element.

spanSelector
(key: K, elements: HierarchyIterable<TNode, T>) => R

A callback used to select a result from a contiguous range.

keyEqualer
Equaler<K>

An Equaler used to compare key equality. Grouping

Returns

spanMap(source, keySelector, keyEqualer)

Creates a subquery whose elements are the contiguous ranges of elements that share the same key.

Declaration
export declare function spanMap<T, K>(source: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<Grouping<K, T>>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyEqualer
Equaler<K>

An Equaler used to compare key equality. Grouping

Returns

spanMap(source, keySelector, elementSelector, keyEqualer)

Creates a subquery whose values are computed from each element of the contiguous ranges of elements that share the same key.

Declaration
export declare function spanMap<T, K, V>(source: Iterable<T>, keySelector: (element: T) => K, elementSelector: (element: T) => V, keyEqualer?: Equaler<K>): Iterable<Grouping<K, V>>;
Type Parameters
T

K

V

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

elementSelector
(element: T) => V

A callback used to select a value for an element.

keyEqualer
Equaler<K>

An Equaler used to compare key equality. Grouping

Returns

spanMap(source, keySelector, elementSelector, spanSelector, keyEqualer)

Creates a subquery whose values are computed from the contiguous ranges of elements that share the same key.

Declaration
export declare function spanMap<T, K, V, R>(source: Iterable<T>, keySelector: (element: T) => K, elementSelector: (element: T) => V, spanSelector: (key: K, elements: Iterable<V>) => R, keyEqualer?: Equaler<K>): Iterable<R>;
Type Parameters
T

K

V

R

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

elementSelector
(element: T) => V

A callback used to select a value for an element.

spanSelector
(key: K, elements: Iterable<V>) => R

A callback used to select a result from a contiguous range.

keyEqualer
Equaler<K>

An Equaler used to compare key equality. Grouping

Returns

spanUntil(source, predicate)

Creates a tuple whose first element is an Iterable containing the first span of elements that do not match the supplied predicate, and whose second element is an Iterable containing the remaining elements.

The first Iterable is eagerly evaluated, while the second Iterable is lazily evaluated.

Declaration
export declare function spanUntil<T>(source: HierarchyIterable<T>, predicate: (element: T, offset: number) => boolean): [HierarchyIterable<T>, HierarchyIterable<T>];
Type Parameters
T

Parameters
source
HierarchyIterable<T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

The predicate used to match elements. Scalar

Returns

spanUntil(source, predicate)

Creates a tuple whose first element is an Iterable containing the first span of elements that do not match the supplied predicate, and whose second element is an Iterable containing the remaining elements.

The first Iterable is eagerly evaluated, while the second Iterable is lazily evaluated.

Declaration
export declare function spanUntil<T>(source: Iterable<T>, predicate: (element: T, offset: number) => boolean): [Iterable<T>, Iterable<T>];
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T, offset: number) => boolean

The predicate used to match elements. Scalar

Returns

startsWith(left, right, equaler)

Computes a scalar value indicating whether the elements of this Query start with the same sequence of elements in another Iterable.

Declaration
export declare function startsWith<T>(left: Iterable<T>, right: Iterable<T>, equaler?: EqualityComparison<T> | Equaler<T>): boolean;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
EqualityComparison<T> | Equaler<T>

A callback used to compare the equality of two elements. Scalar

Returns

startsWith(left, right, equaler)

Computes a scalar value indicating whether the elements of this Query start with the same sequence of elements in another Iterable.

Declaration
export declare function startsWith<T, U>(left: Iterable<T>, right: Iterable<U>, equaler: (left: T, right: U) => boolean): boolean;
Type Parameters
T

U

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<U>

An Iterable object.

equaler
(left: T, right: U) => boolean

A callback used to compare the equality of two elements. Scalar

Returns

sum(source)

Computes the sum for a series of numbers.

Declaration
export declare function sum(source: Iterable<number>): number;
Parameters
source
Iterable<number>

An Iterable object. Scalar

Returns

sum(source, elementSelector)

Computes the sum for a series of numbers.

Declaration
export declare function sum<T>(source: Iterable<T>, elementSelector: (element: T) => number): number;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

elementSelector
(element: T) => number

A callback used to convert a value in source to a number. Scalar

Returns

symmetricDifference(left, right, equaler)

Creates a subquery for the symmetric difference between two Iterable objects. The result is an Iterable containings the elements that exist in only left or right, but not in both.

Declaration
export declare function symmetricDifference<TNode, T extends TNode>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, equaler?: Equaler<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
HierarchyIterable<TNode, T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

symmetricDifference(left, right, equaler)

Creates a subquery for the symmetric difference between two Iterable objects. The result is an Iterable containings the elements that exist in only left or right, but not in both.

Declaration
export declare function symmetricDifference<TNode, T extends TNode>(left: Iterable<T>, right: HierarchyIterable<TNode, T>, equaler?: Equaler<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
Iterable<T>

An Iterable object.

right
HierarchyIterable<TNode, T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

symmetricDifference(left, right, equaler)

Creates a subquery for the symmetric difference between two Iterable objects. The result is an Iterable containings the elements that exist in only left or right, but not in both.

Declaration
export declare function symmetricDifference<T>(left: Iterable<T>, right: Iterable<T>, equaler?: Equaler<T>): Iterable<T>;
Type Parameters
T

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

symmetricDifferenceBy(left, right, keySelector, keyEqualer)

Creates a subquery for the symmetric difference between two Iterable objects, where set identity is determined by the selected key. The result is an Iterable containings the elements that exist in only left or right, but not in both.

Declaration
export declare function symmetricDifferenceBy<TNode, T extends TNode, K>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
left
HierarchyIterable<TNode, T>

An Iterable object.

right
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

symmetricDifferenceBy(left, right, keySelector, keyEqualer)

Creates a subquery for the symmetric difference between two Iterable objects, where set identity is determined by the selected key. The result is an Iterable containings the elements that exist in only left or right, but not in both.

Declaration
export declare function symmetricDifferenceBy<TNode, T extends TNode, K>(left: Iterable<T>, right: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
left
Iterable<T>

An Iterable object.

right
HierarchyIterable<TNode, T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

symmetricDifferenceBy(left, right, keySelector, keyEqualer)

Creates a subquery for the symmetric difference between two Iterable objects, where set identity is determined by the selected key. The result is an Iterable containings the elements that exist in only left or right, but not in both.

Declaration
export declare function symmetricDifferenceBy<T, K>(left: Iterable<T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<T>;
Type Parameters
T

K

Parameters
left
Iterable<T>

An Iterable object.

right
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

take(source, count)

Creates a subquery containing the first elements up to the supplied count.

Declaration
export declare function take<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, count: number): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

count
number

The number of elements to take. Subquery

Returns

take(source, count)

Creates a subquery containing the first elements up to the supplied count.

Declaration
export declare function take<T>(source: Iterable<T>, count: number): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

count
number

The number of elements to take. Subquery

Returns

takeRight(source, count)

Creates a subquery containing the last elements up to the supplied count.

Declaration
export declare function takeRight<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, count: number): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

count
number

The number of elements to take. Subquery

Returns

takeRight(source, count)

Creates a subquery containing the last elements up to the supplied count.

Declaration
export declare function takeRight<T>(source: Iterable<T>, count: number): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

count
number

The number of elements to take. Subquery

Returns

takeUntil(source, predicate)

Creates a subquery containing the first elements that do not match the supplied predicate.

Declaration
export declare function takeUntil<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (element: T) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T) => element is U

A callback used to match each element. Subquery

Returns

takeUntil(source, predicate)

Creates a subquery containing the first elements that do not match the supplied predicate.

Declaration
export declare function takeUntil<T, U extends T>(source: Iterable<T>, predicate: (element: T) => element is U): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => element is U

A callback used to match each element. Subquery

Returns

takeUntil(source, predicate)

Creates a subquery containing the first elements that do not match the supplied predicate.

Declaration
export declare function takeUntil<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate: (element: T) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

takeUntil(source, predicate)

Creates a subquery containing the first elements that do not match the supplied predicate.

Declaration
export declare function takeUntil<T>(source: Iterable<T>, predicate: (element: T) => boolean): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

takeWhile(source, predicate)

Creates a subquery containing the first elements that match the supplied predicate.

Declaration
export declare function takeWhile<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (element: T) => element is U): HierarchyIterable<TNode, U>;
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T) => element is U

A callback used to match each element. Subquery

Returns

takeWhile(source, predicate)

Creates a subquery containing the first elements that match the supplied predicate.

Declaration
export declare function takeWhile<T, U extends T>(source: Iterable<T>, predicate: (element: T) => element is U): Iterable<U>;
Type Parameters
T

U

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => element is U

A callback used to match each element. Subquery

Returns

takeWhile(source, predicate)

Creates a subquery containing the first elements that match the supplied predicate.

Declaration
export declare function takeWhile<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate: (element: T) => boolean): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

takeWhile(source, predicate)

Creates a subquery containing the first elements that match the supplied predicate.

Declaration
export declare function takeWhile<T>(source: Iterable<T>, predicate: (element: T) => boolean): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

predicate
(element: T) => boolean

A callback used to match each element. Subquery

Returns

tap(source, callback)

Lazily invokes a callback as each element of the iterable is iterated.

Declaration
export declare function tap<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, callback: (element: T, offset: number) => void): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

A Iterable object.

callback
(element: T, offset: number) => void

The callback to invoke. Subquery

Returns

tap(source, callback)

Lazily invokes a callback as each element of the iterable is iterated.

Declaration
export declare function tap<T>(source: Iterable<T>, callback: (element: T, offset: number) => void): Iterable<T>;
Type Parameters
T

Parameters
source
Iterable<T>

A Iterable object.

callback
(element: T, offset: number) => void

The callback to invoke. Subquery

Returns

thenBy(source, keySelector, keyComparer)

Creates a subsequent OrderedIterable whose elements are also sorted in ascending order by the provided key.

Declaration
export declare function thenBy<TNode, T extends TNode, K>(source: OrderedHierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedHierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
OrderedHierarchyIterable<TNode, T>

An OrderedIterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

thenBy(source, keySelector, keyComparer)

Creates a subsequent OrderedIterable whose elements are also sorted in ascending order by the provided key.

Declaration
export declare function thenBy<T, K>(source: OrderedIterable<T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedIterable<T>;
Type Parameters
T

K

Parameters
source
OrderedIterable<T>

An OrderedIterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

thenByDescending(source, keySelector, keyComparer)

Creates a subsequent OrderedIterable whose elements are also sorted in descending order by the provided key.

Declaration
export declare function thenByDescending<TNode, T extends TNode, K>(source: OrderedHierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedHierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
source
OrderedHierarchyIterable<TNode, T>

An OrderedIterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

thenByDescending(source, keySelector, keyComparer)

Creates a subsequent OrderedIterable whose elements are also sorted in descending order by the provided key.

Declaration
export declare function thenByDescending<T, K>(source: OrderedIterable<T>, keySelector: (element: T) => K, keyComparer?: Comparison<K> | Comparer<K>): OrderedIterable<T>;
Type Parameters
T

K

Parameters
source
OrderedIterable<T>

An OrderedIterable object.

keySelector
(element: T) => K

A callback used to select the key for an element.

keyComparer
Comparison<K> | Comparer<K>

An optional callback used to compare two keys. Order

Returns

toArray(source)

Creates an Array for the elements of the Iterable.

Declaration
export declare function toArray<T>(source: Iterable<T>): T[];
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object. Scalar

Returns
T[]

toArray(source, elementSelector)

Creates an Array for the elements of the Iterable.

Declaration
export declare function toArray<T, V>(source: Iterable<T>, elementSelector: (element: T) => V): V[];
Type Parameters
T

V

Parameters
source
Iterable<T>

An Iterable object.

elementSelector
(element: T) => V

A callback that selects a value for each element. Scalar

Returns
V[]

toHashMap(source, keySelector, keyEqualer)

Creates a HashMap for the elements of the Query.

Declaration
export declare function toHashMap<T, K>(source: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HashMap<K, T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select a key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Scalar

Returns
HashMap<K, T>

toHashMap(source, keySelector, elementSelector, keyEqualer)

Creates a Map for the elements of the Query.

Declaration
export declare function toHashMap<T, K, V>(source: Iterable<T>, keySelector: (element: T) => K, elementSelector: (element: T) => V, keyEqualer?: Equaler<K>): HashMap<K, V>;
Type Parameters
T

K

V

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Scalar

Returns
HashMap<K, V>

toHashSet(source, equaler)

Creates a HashSet for the elements of the Iterable.

Declaration
export declare function toHashSet<T>(source: Iterable<T>, equaler?: Equaler<T>): HashSet<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

equaler
Equaler<T>

An Equaler object used to compare equality. Scalar

Returns

toHashSet(source, elementSelector, equaler)

Creates a Set for the elements of the Iterable.

Declaration
export declare function toHashSet<T, V>(source: Iterable<T>, elementSelector: (element: T) => V, equaler?: Equaler<V>): HashSet<V>;
Type Parameters
T

V

Parameters
source
Iterable<T>

An Iterable object.

elementSelector
(element: T) => V

A callback that selects a value for each element.

equaler
Equaler<V>

An Equaler object used to compare equality. Scalar

Returns

toHierarchy(iterable, provider)

Creates a HierarchyIterable using the provided HierarchyProvider.

Declaration
export declare function toHierarchy<TNode, T extends TNode = TNode>(iterable: OrderedIterable<T>, provider: HierarchyProvider<TNode>): OrderedHierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
iterable
OrderedIterable<T>

provider
HierarchyProvider<TNode>

Returns

toHierarchy(iterable, provider)

Declaration
export declare function toHierarchy<TNode, T extends TNode = TNode>(iterable: Iterable<T>, provider: HierarchyProvider<TNode>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
iterable
Iterable<T>

provider
HierarchyProvider<TNode>

Returns

toLookup(source, keySelector, keyEqualer)

Creates a Lookup for the elements of the Query.

Declaration
export declare function toLookup<T, K>(source: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Lookup<K, T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select a key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Scalar

Returns
Lookup<K, T>

toLookup(source, keySelector, elementSelector, keyEqualer)

Creates a Lookup for the elements of the Query.

Declaration
export declare function toLookup<T, K, V>(source: Iterable<T>, keySelector: (element: T) => K, elementSelector: (element: T) => V, keyEqualer?: Equaler<K>): Lookup<K, V>;
Type Parameters
T

K

V

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Scalar

Returns
Lookup<K, V>

toMap(source, keySelector)

Creates a Map for the elements of the Query.

Declaration
export declare function toMap<T, K>(source: Iterable<T>, keySelector: (element: T) => K): Map<K, T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select a key for each element. Scalar

Returns
Map<K, T>

toMap(source, keySelector, elementSelector)

Creates a Map for the elements of the Query.

Declaration
export declare function toMap<T, K, V>(source: Iterable<T>, keySelector: (element: T) => K, elementSelector: (element: T) => V): Map<K, V>;
Type Parameters
T

K

V

Parameters
source
Iterable<T>

An Iterable object.

keySelector
(element: T) => K

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element. Scalar

Returns
Map<K, V>

toObject(source, prototype, keySelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function
obj.toString(); // "x",1:"y",2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, TProto extends object, K extends PropertyKey>(source: Iterable<T>, prototype: TProto, keySelector: (element: T) => K): TProto & Record<K, T>;
Type Parameters
T

TProto

K

Parameters
source
Iterable<T>

An Iterable object.

prototype
TProto

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => K

A callback used to select a key for each element. Scalar

Returns
TProto & Record<K, T>

toObject(source, prototype, keySelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function
obj.toString(); // "x",1:"y",2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, TProto extends object>(source: Iterable<T>, prototype: TProto, keySelector: (element: T) => PropertyKey): TProto & Record<PropertyKey, T>;
Type Parameters
T

TProto

Parameters
source
Iterable<T>

An Iterable object.

prototype
TProto

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => PropertyKey

A callback used to select a key for each element. Scalar

Returns
TProto & Record<PropertyKey, T>

toObject(source, prototype, keySelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function
obj.toString(); // "x",1:"y",2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, K extends PropertyKey>(source: Iterable<T>, prototype: object | null | undefined, keySelector: (element: T) => K): Record<K, T>;
Type Parameters
T

K

Parameters
source
Iterable<T>

An Iterable object.

prototype
object | null | undefined

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => K

A callback used to select a key for each element. Scalar

Returns
Record<K, T>

toObject(source, prototype, keySelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // function
obj.toString(); // "x",1:"y",2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0]);
obj.x; // ["x", 1]
obj.y; // ["y", 2]
typeof obj.toString; // undefined
Declaration
export declare function toObject<T>(source: Iterable<T>, prototype: object | null | undefined, keySelector: (element: T) => PropertyKey): Record<PropertyKey, T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object.

prototype
object | null | undefined

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => PropertyKey

A callback used to select a key for each element. Scalar

Returns
Record<PropertyKey, T>

toObject(source, prototype, keySelector, elementSelector, descriptorSelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function
obj.toString(); // 1:2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, TProto extends object, K extends PropertyKey, V>(source: Iterable<T>, prototype: TProto, keySelector: (element: T) => K, elementSelector: (element: T) => V, descriptorSelector?: (key: K, value: V) => TypedPropertyDescriptor<V>): TProto & Record<K, V>;
Type Parameters
T

TProto

K

V

Parameters
source
Iterable<T>

An Iterable object.

prototype
TProto

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => K

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element.

descriptorSelector
(key: K, value: V) => TypedPropertyDescriptor<V>

A callback that defines the PropertyDescriptor for each property. Scalar

Returns
TProto & Record<K, V>

toObject(source, prototype, keySelector, elementSelector, descriptorSelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function
obj.toString(); // 1:2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, TProto extends object, V>(source: Iterable<T>, prototype: TProto, keySelector: (element: T) => PropertyKey, elementSelector: (element: T) => V, descriptorSelector?: (key: PropertyKey, value: V) => TypedPropertyDescriptor<V>): TProto & Record<PropertyKey, V>;
Type Parameters
T

TProto

V

Parameters
source
Iterable<T>

An Iterable object.

prototype
TProto

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => PropertyKey

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element.

descriptorSelector
(key: PropertyKey, value: V) => TypedPropertyDescriptor<V>

A callback that defines the PropertyDescriptor for each property. Scalar

Returns
TProto & Record<PropertyKey, V>

toObject(source, prototype, keySelector, elementSelector, descriptorSelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function
obj.toString(); // 1:2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, K extends PropertyKey, V>(source: Iterable<T>, prototype: object | null | undefined, keySelector: (element: T) => K, elementSelector: (element: T) => V, descriptorSelector?: (key: K, value: V) => TypedPropertyDescriptor<V>): Record<K, V>;
Type Parameters
T

K

V

Parameters
source
Iterable<T>

An Iterable object.

prototype
object | null | undefined

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => K

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element.

descriptorSelector
(key: K, value: V) => TypedPropertyDescriptor<V>

A callback that defines the PropertyDescriptor for each property. Scalar

Returns
Record<K, V>

toObject(source, prototype, keySelector, elementSelector, descriptorSelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function
obj.toString(); // 1:2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, V>(source: Iterable<T>, prototype: object | null | undefined, keySelector: (element: T) => PropertyKey, elementSelector: (element: T) => V, descriptorSelector?: (key: PropertyKey, value: V) => TypedPropertyDescriptor<V>): Record<PropertyKey, V>;
Type Parameters
T

V

Parameters
source
Iterable<T>

An Iterable object.

prototype
object | null | undefined

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => PropertyKey

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element.

descriptorSelector
(key: PropertyKey, value: V) => TypedPropertyDescriptor<V>

A callback that defines the PropertyDescriptor for each property. Scalar

Returns
Record<PropertyKey, V>

toObject(source, prototype, keySelector, elementSelector, descriptorSelector)

Creates an Object for the elements of source. Properties are added via Object.defineProperty.

// As a regular object
const obj = toObject(`"`, 1], ["y", 2]], undefined, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function

// with a custom prototype
const baseObject = { toString() { return `${this.x}:${this.y}` } };
const obj = toObject(`"`, 1], ["y", 2]], baseObject, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // function
obj.toString(); // 1:2

// with a null prototype
const obj = toObject(`"`, 1], ["y", 2]], null, a => a[0], a => a[1]);
obj.x; // 1
obj.y; // 2
typeof obj.toString; // undefined
Declaration
export declare function toObject<T, V>(source: Iterable<T>, prototype: object | null | undefined, keySelector: (element: T) => PropertyKey, elementSelector: (element: T) => V, descriptorSelector?: (key: PropertyKey, value: V) => PropertyDescriptor): object;
Type Parameters
T

V

Parameters
source
Iterable<T>

An Iterable object.

prototype
object | null | undefined

The prototype for the object. If prototype is null, an object with a null prototype is created. If prototype is undefined, the default Object.prototype is used.

keySelector
(element: T) => PropertyKey

A callback used to select a key for each element.

elementSelector
(element: T) => V

A callback that selects a value for each element.

descriptorSelector
(key: PropertyKey, value: V) => PropertyDescriptor

A callback that defines the PropertyDescriptor for each property. Scalar

Returns

topMost(source, predicate, equaler)

Filters a HierarchyIterable to the top-most elements. Elements that are a descendant of any other element in the iterable are removed.

Declaration
export declare function topMost<TNode, T extends TNode, U extends T>(source: HierarchyIterable<TNode, T>, predicate: (value: T) => value is U, equaler?: Equaler<TNode>): HierarchyIterable<TNode, U>;
Type Parameters
TNode

T

U

Parameters
source
HierarchyIterable<TNode, T>

A HierarchyIterable object.

predicate
(value: T) => value is U

An optional callback used to filter the results.

equaler
Equaler<TNode>

An optional Equaler used to compare equality between nodes. Hierarchy

Returns

topMost(source, predicate, equaler)

Creates a HierarchyIterable for the top-most elements. Elements that are a descendant of any other element are removed.

Declaration
export declare function topMost<TNode, T extends TNode>(source: HierarchyIterable<TNode, T>, predicate?: (value: T) => boolean, equaler?: Equaler<TNode>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
source
HierarchyIterable<TNode, T>

A HierarchyIterable object.

predicate
(value: T) => boolean

An optional callback used to filter the results.

equaler
Equaler<TNode>

An optional Equaler used to compare equality between nodes. Hierarchy

Returns

toSet(source)

Creates a Set for the elements of the Iterable.

Declaration
export declare function toSet<T>(source: Iterable<T>): Set<T>;
Type Parameters
T

Parameters
source
Iterable<T>

An Iterable object. Scalar

Returns
Set<T>

toSet(source, elementSelector)

Creates a Set for the elements of the Iterable.

Declaration
export declare function toSet<T, V>(source: Iterable<T>, elementSelector: (element: T) => V): Set<V>;
Type Parameters
T

V

Parameters
source
Iterable<T>

An Iterable object.

elementSelector
(element: T) => V

A callback that selects a value for each element. Scalar

Returns
Set<V>

union(left, right, equaler)

Creates a subquery for the set union of two Iterable objects.

Declaration
export declare function union<TNode, T extends TNode>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, equaler?: Equaler<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
HierarchyIterable<TNode, T>

A Iterable value.

right
Iterable<T>

A Iterable value.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

union(left, right, equaler)

Creates a subquery for the set union of two Iterable objects.

Declaration
export declare function union<TNode, T extends TNode>(left: Iterable<T>, right: HierarchyIterable<TNode, T>, equaler?: Equaler<T>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

Parameters
left
Iterable<T>

A Iterable value.

right
HierarchyIterable<TNode, T>

A Iterable value.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

union(left, right, equaler)

Creates a subquery for the set union of two Iterable objects.

Declaration
export declare function union<T>(left: Iterable<T>, right: Iterable<T>, equaler?: Equaler<T>): Iterable<T>;
Type Parameters
T

Parameters
left
Iterable<T>

A Iterable value.

right
Iterable<T>

A Iterable value.

equaler
Equaler<T>

An Equaler object used to compare equality. Subquery

Returns

unionBy(left, right, keySelector, keyEqualer)

Creates a subquery for the set union of two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function unionBy<TNode, T extends TNode, K>(left: HierarchyIterable<TNode, T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
left
HierarchyIterable<TNode, T>

A Iterable value.

right
Iterable<T>

A Iterable value.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

unionBy(left, right, keySelector, keyEqualer)

Creates a subquery for the set union of two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function unionBy<TNode, T extends TNode, K>(left: Iterable<T>, right: HierarchyIterable<TNode, T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): HierarchyIterable<TNode, T>;
Type Parameters
TNode

T

K

Parameters
left
Iterable<T>

A Iterable value.

right
HierarchyIterable<TNode, T>

A Iterable value.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

unionBy(left, right, keySelector, keyEqualer)

Creates a subquery for the set union of two Iterable objects, where set identity is determined by the selected key.

Declaration
export declare function unionBy<T, K>(left: Iterable<T>, right: Iterable<T>, keySelector: (element: T) => K, keyEqualer?: Equaler<K>): Iterable<T>;
Type Parameters
T

K

Parameters
left
Iterable<T>

A Iterable value.

right
Iterable<T>

A Iterable value.

keySelector
(element: T) => K

A callback used to select the key for each element.

keyEqualer
Equaler<K>

An Equaler object used to compare key equality. Subquery

Returns

unzip(source)

Unzips a sequence of tuples into a tuple of sequences.

Declaration
export declare function unzip<T extends readonly any[] | []>(source: Iterable<T>): {
    [I in keyof T]: T[I][];
};
Type Parameters
T

Parameters
source
Iterable<T>

A Iterable Scalar

Returns
{ [I in keyof T]: T[I][]; }

unzip(source, partSelector)

Unzips a sequence of tuples into a tuple of sequences.

Declaration
export declare function unzip<T, U extends readonly any[] | []>(source: Iterable<T>, partSelector: (value: T) => U): {
    [I in keyof U]: U[I][];
};
Type Parameters
T

U

Parameters
source
Iterable<T>

A Iterable

partSelector
(value: T) => U

A callback that converts a result into a tuple. Scalar

Returns
{ [I in keyof U]: U[I][]; }

zip(left, right)

Creates a subquery that combines two Iterable objects by combining elements in tuples.

Declaration
export declare function zip<T, U>(left: Iterable<T>, right: Iterable<U>): Iterable<[T, U]>;
Type Parameters
T

U

Parameters
left
Iterable<T>

A Iterable.

right
Iterable<U>

A Iterable. Join

Returns
Iterable<[T, U]>

zip(left, right, selector)

Creates a subquery that combines two Iterable objects by combining elements using the supplied callback.

Declaration
export declare function zip<T, U, R>(left: Iterable<T>, right: Iterable<U>, selector: (left: T, right: U) => R): Iterable<R>;
Type Parameters
T

U

R

Parameters
left
Iterable<T>

A Iterable.

right
Iterable<U>

A Iterable.

selector
(left: T, right: U) => R

A callback used to combine two elements. Join

Returns