Class WritableArraySignal<T>

A writable signal for arrays. Provides pretty much all common array functions while automatically tracking changes.

Type Parameters

Hierarchy (View Summary)

BaseSignal<readonly T[]>
- WritableArraySignal

Implements

RelativeIndexable<T>

WritableArraySignal(...args: []): readonly T[]
Parameters
- ...args: []
Returns readonly T[]
- Defined in WritableArraySignal.ts:16

Constructors

constructor

new WritableArraySignal<T>(
elements?: T[],
options?: BaseSignalOptions<T>,
): WritableArraySignal<T>
Creates new writable array signal initialized to the given elements.
Type Parameters
- T
Parameters
- Optionalelements: T[]
  The initial elements to copy into the array signal. Defaults to empty array.
- options: BaseSignalOptions<T> = {}
  Optional signal options.
Returns WritableArraySignal<T>
Overrides BaseSignal.constructor
- Defined in WritableArraySignal.ts:29

Methods

[iterator]

"[iterator]"(): ArrayIterator<T>
Returns ArrayIterator<T>
An iterable of values in the array.
- Defined in WritableArraySignal.ts:453

[observable]

"[observable]"(): InteropSubscribable<readonly T[]>
Returns InteropSubscribable<readonly T[]>
Inherit Doc
Inherited from BaseSignal.[observable]
- Defined in BaseSignal.ts:142

asReadonly

asReadonly(): ReadonlyArraySignal<T>
Returns ReadonlyArraySignal<T>
A readonly signal wrapping this signal.
- Defined in WritableArraySignal.ts:460

at

at(index: number): undefined | T
Returns the element at the given index.
Parameters
- index: number
  The array index. A negative index will count back from the last item.
Returns undefined | T
The element at the given index, or undefined if none.
Implementation of RelativeIndexable.at
- Defined in WritableArraySignal.ts:446

concat

concat(...items: ConcatArray<T>[]): T[]
Parameters
- ...items: ConcatArray<T>[]
Returns T[]
- Defined in WritableArraySignal.ts:119
concat(...items: (T | ConcatArray<T>)[]): T[]
Parameters
- ...items: (T | ConcatArray<T>)[]
Returns T[]
- Defined in WritableArraySignal.ts:120

copyWithin

copyWithin(target: number, start: number, end?: number): this
Copies a section of the array identified by start and end to the same array starting at position target.
Parameters
- target: number
  The target index to copy the section to. If negative then it is treated as length+target where length is the length of the array.
- start: number
  The start index of the section to copy. If negative then it is treated as length+start.
- Optionalend: number
  Optional end index (exclusive) of the section to copy. If not specified, length of the array is used as end. If end is negative, it is treated as length+end.
Returns this
- Defined in WritableArraySignal.ts:390

entries

entries(): ArrayIterator<[number, T]>
Returns ArrayIterator<[number, T]>
An iterable of key/value pairs for every entry in the array.
- Defined in WritableArraySignal.ts:398

every

every<S>(
predicate: (value: T, index: number, array: readonly T[]) => value is S,
thisArg?: unknown,
): this is readonly S[]
Type Parameters
- S
Parameters
- predicate: (value: T, index: number, array: readonly T[]) => value is S
- OptionalthisArg: unknown
Returns this is readonly S[]
- Defined in WritableArraySignal.ts:244
every(
predicate: (value: T, index: number, array: readonly T[]) => unknown,
thisArg?: unknown,
): boolean
Parameters
- predicate: (value: T, index: number, array: readonly T[]) => unknown
- OptionalthisArg: unknown
Returns boolean
- Defined in WritableArraySignal.ts:245

fill

fill(value: T, start?: number, end?: number): this
Changes all array elements from start to end index to a static value.
Parameters
- value: T
  The value to fill array section with.
- Optionalstart: number
  Optional index to start filling the array at. Defaults to 0. If start is negative, it is treated as length+start.
- Optionalend: number
  Optional index to stop filling the array at. Defaults to length. If end is negative, it is treated as length+end.
Returns this
- Defined in WritableArraySignal.ts:377

filter

filter<S>(
predicate: (value: T, index: number, array: readonly T[]) => value is S,
thisArg?: unknown,
): S[]
Type Parameters
- S
Parameters
- predicate: (value: T, index: number, array: readonly T[]) => value is S
- OptionalthisArg: unknown
Returns S[]
- Defined in WritableArraySignal.ts:294
filter(
predicate: (value: T, index: number, array: readonly T[]) => unknown,
thisArg?: unknown,
): T[]
Parameters
- predicate: (value: T, index: number, array: readonly T[]) => unknown
- OptionalthisArg: unknown
Returns T[]
- Defined in WritableArraySignal.ts:295

find

find<S>(
predicate: (value: T, index: number, obj: readonly T[]) => value is S,
thisArg?: unknown,
): undefined | S
Type Parameters
- S
Parameters
- predicate: (value: T, index: number, obj: readonly T[]) => value is S
- OptionalthisArg: unknown
Returns undefined | S
- Defined in WritableArraySignal.ts:343
find(
predicate: (value: T, index: number, obj: readonly T[]) => boolean,
thisArg?: unknown,
): undefined | T
Parameters
- predicate: (value: T, index: number, obj: readonly T[]) => boolean
- OptionalthisArg: unknown
Returns undefined | T
- Defined in WritableArraySignal.ts:344

findIndex

findIndex(
predicate: (value: T, index: number, obj: readonly T[]) => boolean,
thisArg?: unknown,
): number
Returns the index of the first element in the array where predicate is true, and -1 otherwise.
Parameters
- predicate: (value: T, index: number, obj: readonly T[]) => boolean
  Called once for each element of the array, in ascending order, until it finds one where predicate returns true. If such an element is found, findIndex immediately returns that element index. Otherwise, findIndex returns -1.
- OptionalthisArg: unknown
  Optional object to which the this keyword can refer in the predicate function. Defaults to undefined.
Returns number
The index of the first found element or -1 if none.
- Defined in WritableArraySignal.ts:366

flatMap

flatMap<U, This = undefined>(
    callback: (
        this: This,
        value: T,
        index: number,
        array: T[],
    ) => U | readonly U[],
    thisArg?: This,
): U[]
Calls the given callback function on each element of the array to map the array element to something different. Then flattens the result into a new array. This is identical to a map followed by flat with depth 1.
Type Parameters
- U
- This = undefined
Parameters
- callback: (this: This, value: T, index: number, array: T[]) => U | readonly U[]
  A function that accepts up to three arguments (value, index, array). Called one time for each element in the array. Must return the mapped value.
- OptionalthisArg: This
  Optional object to which the this keyword can refer in the callback function. Defaults to undefined.
Returns U[]
New array with mapped and flattened valued.
- Defined in WritableArraySignal.ts:436

forEach

forEach(
callback: (value: T, index: number, array: readonly T[]) => void,
thisArg?: unknown,
): void
Performs the specified action for each element in the array.
Parameters
- callback: (value: T, index: number, array: readonly T[]) => void
  A function that accepts up to three arguments (value, index and the array itself). Called one time for each element in the array.
- OptionalthisArg: unknown
  Optional object to which the this keyword can refer in the callback function. Defaults to undefined.
Returns void
- Defined in WritableArraySignal.ts:278

get

get(): readonly T[]
Returns readonly T[]
The current signal value.
Inherited from BaseSignal.get
- Defined in BaseSignal.ts:69

getVersion

getVersion(): number
Returns the current signal value version. This version is incremented every time the signal value has really changed. The version starts by 0 and wraps to Number.MIN_SAFE_INTEGER when Number.MAX_SAFE_INTEGER is reached, allowing unique versions for eighteen quadrillion signal updates.

Returns number
The current signal version.
Inherited from BaseSignal.getVersion
- Defined in BaseSignal.ts:163

includes

includes(searchElement: T, fromIndex?: number): boolean
Determines whether an array includes a certain element, returning true or false as appropriate.
Parameters
- searchElement: T
  The element to search for.
- OptionalfromIndex: number
  Optional position in this array at which to begin searching. Defaults to 0.
Returns boolean
True if array includes the element, false if not.
- Defined in WritableArraySignal.ts:423

indexOf

indexOf(searchElement: T, fromIndex?: number): number
Returns the index of the first occurrence of an element in the array.
Parameters
- searchElement: T
  The element to locate in the array.
- fromIndex: number = 0
  The array index at which to begin the search. If omitted, the search starts at index 0.
Returns number
The index of the first occurrence of the given element, or -1 if not found.
- Defined in WritableArraySignal.ts:229

isValid

isValid(): boolean
Checks if signal value is still valid. When signal has no dependencies then this method can always return true. If signal has dependencies then it must check if any dependency has changed or became invalid. If yes, then this method must return false and the signal will be re-validated by calling (). If all dependency are valid/unchanged then this method must return true to indicate that the signal value is still valid.

Returns boolean
True if signal value is valid, false if it must be re-validated.
Inherited from BaseSignal.isValid
- Defined in BaseSignal.ts:168

isWatched

isWatched(): boolean
Returns boolean
True if signal is watched (has subscribed observers) or false if not.
Inherited from BaseSignal.isWatched
- Defined in BaseSignal.ts:147

join

join(separator?: string): string
Adds all the elements of the array separated by the specified separator string.
Parameters
- Optionalseparator: string
  A string used to separate one element of an array from the next in the resulting string. If omitted, the array elements are separated with a comma.
Returns string
The joined string.
- Defined in WritableArraySignal.ts:139

keys

keys(): ArrayIterator<number>
Returns ArrayIterator<number>
An iterable of keys in the array.
- Defined in WritableArraySignal.ts:405

lastIndexOf

lastIndexOf(searchElement: T, fromIndex?: number): number
Returns the index of the last occurrence of an element in the array.
Parameters
- searchElement: T
  The element to locate in the array.
- fromIndex: number = -1
  The array index at which to begin the search. If omitted, the search starts at the last index in the array.
Returns number
The index of the last occurrence of the given element, or -1 if not found.
- Defined in WritableArraySignal.ts:240

map

map<U>(
callback: (value: T, index: number, array: readonly T[]) => U,
thisArg?: unknown,
): U[]
Calls a defined callback function on each element of the array and returns an array that contains the results.
Type Parameters
- U
Parameters
- callback: (value: T, index: number, array: readonly T[]) => U
  A function that accepts up to three arguments (value, index and the array itself) and returns the mapped value for the array element. Called one time for each element in the array.
- OptionalthisArg: unknown
  Optional object to which the this keyword can refer in the callback function. Defaults to undefined.
Returns U[]
A new array with the mapped elements.
- Defined in WritableArraySignal.ts:290

pop

pop(): undefined | T
Removes the last element from the array and returns it. If the array is empty, undefined is returned and the array is not modified.

Returns undefined | T
The popped element or undefined if array is empty.
- Defined in WritableArraySignal.ts:97

push

push(...newElements: T[]): number
Appends new elements to the end of the array and returns the new length of the array.
Parameters
- ...newElements: T[]
  New elements to add to the array.
Returns number
The new length of the array.
- Defined in WritableArraySignal.ts:111

reduce

reduce<U>(
    callback: (
        previousValue: U,
        currentValue: T,
        currentIndex: number,
        array: readonly T[],
    ) => U,
    initialValue: U,
): U
Type Parameters
- U
Parameters
- callback: (
      previousValue: U,
      currentValue: T,
      currentIndex: number,
      array: readonly T[],
  ) => U
- initialValue: U
Returns U
- Defined in WritableArraySignal.ts:309
reduce(
    callback: (
        previousValue: T,
        currentValue: T,
        currentIndex: number,
        array: readonly T[],
    ) => T,
    initialValue?: T,
): T
Parameters
- callback: (
      previousValue: T,
      currentValue: T,
      currentIndex: number,
      array: readonly T[],
  ) => T
- OptionalinitialValue: T
Returns T
- Defined in WritableArraySignal.ts:310

reduceRight

reduceRight<U>(
    callback: (
        previousValue: U,
        currentValue: T,
        currentIndex: number,
        array: readonly T[],
    ) => U,
    initialValue: U,
): U
Type Parameters
- U
Parameters
- callback: (
      previousValue: U,
      currentValue: T,
      currentIndex: number,
      array: readonly T[],
  ) => U
- initialValue: U
Returns U
- Defined in WritableArraySignal.ts:326
reduceRight(
    callback: (
        previousValue: T,
        currentValue: T,
        currentIndex: number,
        array: readonly T[],
    ) => T,
    initialValue?: T,
): T
Parameters
- callback: (
      previousValue: T,
      currentValue: T,
      currentIndex: number,
      array: readonly T[],
  ) => T
- OptionalinitialValue: T
Returns T
- Defined in WritableArraySignal.ts:327

reverse

reverse(): this
Reverses the elements in the array in place. Does nothing when array has fewer than 2 elements.

Returns this
- Defined in WritableArraySignal.ts:146

set

set(elements: T[]): this
Sets new array elements. This copies the given elements into the array, so modification of the input array does not accidentally modify the signal.
Parameters
- elements: T[]
  The new array elements to set.
Returns this
Overrides BaseSignal.set
- Defined in WritableArraySignal.ts:57

setAt

setAt(index: number, element: T): this
Sets an array element.
Parameters
- index: number
  The array index.
- element: T
  The element to set.
Returns this
- Defined in WritableArraySignal.ts:67

shift

shift(): undefined | T
Removes the first element from the array and returns it. If the array is empty, undefined is returned and the array is not modified.

Returns undefined | T
The shifted element or undefined if array is empty.
- Defined in WritableArraySignal.ts:158

slice

slice(start?: number, end?: number): T[]
Returns a section of the array.
Parameters
- Optionalstart: number
  The beginning of the specified portion of the array.
- Optionalend: number
  Optional end of the specified portion of the array. This is exclusive of the element at the index 'end'. Defaults to the array length if not specified.
Returns T[]
The sliced section of the array.
- Defined in WritableArraySignal.ts:174

some

some(
predicate: (value: T, index: number, array: readonly T[]) => boolean,
thisArg?: unknown,
): boolean
Determines whether the specified callback function returns true for any element of the array.
Parameters
- predicate: (value: T, index: number, array: readonly T[]) => boolean
  A function that accepts up to three arguments (value, index and the array itself). Called for each element in the array until the predicate returns a value which is coercible to the Boolean value true, or until the end of the array.
- OptionalthisArg: unknown
  Optional object to which the this keyword can refer in the predicate function. Defaults to undefined.
Returns boolean
True if at least one element satisfies the specified test, false if none does.
- Defined in WritableArraySignal.ts:267

sort

sort(compareFn?: (a: T, b: T) => number): this
Sorts an array in place. This method mutates the array and returns a reference to the same array. Does nothing if element has less than two elements.
Parameters
- OptionalcompareFn: (a: T, b: T) => number
  Function used to determine the order of the elements. It is expected to return a negative value if the first argument is less than the second argument, zero if they are equal, and a positive value otherwise. If omitted, the elements are sorted in ascending, ASCII character order.
Returns this
- Defined in WritableArraySignal.ts:185

splice

splice(start: number, deleteCount?: number, ...newElements: T[]): T[]
Removes elements from the array and, if necessary, inserts new elements in their place, returning the deleted elements.
Parameters
- start: number
  The zero-based location in the array from which to start removing elements.
- deleteCount: number = 0
  Optional number of elements to remove. Defaults to 0.
- ...newElements: T[]
  Elements to insert into the array in place of the deleted elements.
Returns T[]
An array containing the elements that were deleted.
- Defined in WritableArraySignal.ts:200

subscribe(
observer: Observer<readonly T[]> | (next: readonly T[]) => void,
): Subscription
Subscribes the given observer to this object.
Parameters
- observer: Observer<readonly T[]> | (next: readonly T[]) => void
  The observer to subscribe.
Returns Subscription
Object which can be used to unsubscribe the observer.
Inherited from BaseSignal.subscribe
- Defined in BaseSignal.ts:127

unshift

unshift(...newElements: T[]): number
Inserts new elements at the start of the array and returns the new length of the array.
Parameters
- ...newElements: T[]
  The elements to insert at the start of the array.
Returns number
The new length of the array.
- Defined in WritableArraySignal.ts:214

`Protected`unwatch

unwatch(): void
Called when last observer unsubscribes.

Returns void
Inherited from BaseSignal.unwatch
- Defined in BaseSignal.ts:155

validate

validate(): void
Called when () returned false and the current value of this signal is needed. Must compute/fetch and cache the new value so the next call to () returns a valid value. When signal has no dependencies and () is implemented to always return true then this method can stay empty as it has nothing to validate/update.

Returns void
Inherited from BaseSignal.validate
- Defined in BaseSignal.ts:173

values

values(): ArrayIterator<T>
Returns ArrayIterator<T>
An iterable of values in the array.
- Defined in WritableArraySignal.ts:412

`Protected`watch

watch(): void
Called when first observer subscribes.

Returns void
Inherited from BaseSignal.watch
- Defined in BaseSignal.ts:152

`Static`from

from<T>(
arrayLike: ArrayLike<T>,
options?: BaseSignalOptions<T>,
): WritableArraySignal<T>
Creates a writable array signal from an array-like object.
Type Parameters
- T
Parameters
- arrayLike: ArrayLike<T>
  An array-like object to convert to an array signal.
- Optionaloptions: BaseSignalOptions<T>
Returns WritableArraySignal<T>
The created writable array signal.
- Defined in WritableArraySignal.ts:48

Class WritableArraySignal<T>

Type Parameters

Hierarchy (View Summary)

Implements

Parameters

Returns readonly T[]

Index

Constructors

Methods

Constructors

constructor

Type Parameters

Parameters

Returns WritableArraySignal<T>

Methods

[iterator]

Returns ArrayIterator<T>

[observable]

Returns InteropSubscribable<readonly T[]>

Inherit Doc

asReadonly

Returns ReadonlyArraySignal<T>

at

Parameters

Returns undefined | T

concat

Parameters

Returns T[]

Parameters

Returns T[]

copyWithin

Parameters

Returns this

entries

Returns ArrayIterator<[number, T]>

every

Type Parameters

Parameters

Returns this is readonly S[]

Parameters

Returns boolean

fill

Parameters

Returns this

filter

Type Parameters

Parameters

Returns S[]

Parameters

Returns T[]

find

Type Parameters

Parameters

Returns undefined | S

Parameters

Returns undefined | T

findIndex

Parameters

Returns number

flatMap

Type Parameters

Parameters

Returns U[]

forEach

Parameters

Returns void

get

Returns readonly T[]

getVersion

Returns number

includes

Parameters

Returns boolean

indexOf

Parameters

Returns number

isValid

Returns boolean

isWatched

Returns boolean

`Protected`unwatch

`Protected`watch

`Static`from