Class IntControl

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defined

• get defined(): Cell<boolean>

  Create a cell the value of which is true if this cell's value is not null or undefined, false otherwise.

  Returns Cell<boolean>

  A cell.

not

• get not(): Cell<boolean>

  Create a cell that negates the value of this cell using the ! operator.

  Returns Cell<boolean>

  A negating cell.

props

• get props(): CellProxyObject<T>

  Returns CellProxyObject<T>

undefined

• get undefined(): Cell<boolean>

  Create a cell the value of which is true if this cell's value is null or undefined, false otherwise.

  Returns Cell<boolean>

  A cell.

value

• get value(): T

  Set the cell's value. This emits the new value to all observers.

  Returns T
• set value(value: T): void

  Set the cell's value. This emits the new value to all observers.

  Parameters

  • value: T

    The new value.

  Returns void

addNode

• addNode(element: Node, context: Context): void

  Parameters

  • element: Node
  • context: Context

  Returns void

and

• and<T2>(other: Cell<T2>): Cell<false | T2>

  Type Parameters

  • T2

  Parameters

  • other: Cell<T2>

  Returns Cell<false | T2>

asCell

• asCell(): Cell<number>

  Convert this cell to an immutable cell. The resulting will no longer be an instance of MutCell but will still update its value whenever this cell is updated.

  Returns Cell<number>

await

• await(onrejected?: (reason: unknown) => void): Cell<undefined | number>

  Parameters

  • Optionalonrejected: (reason: unknown) => void

  Returns Cell<undefined | number>

bimap

• bimap<T2>(
      encode: (value: number) => T2,
      decode: (value: T2) => number,
  ): MutCell<T2>

  Create a two-way binding that modified values in both directions. The resulting cell is mutable and any modification of it will also result in an update of this cell.

  Type Parameters

  • T2

  Parameters

  • encode: (value: number) => T2

    Applied to the value of this cell to get the value of the resulting cell.
  • decode: (value: T2) => number

    Applied to the value of the resulting cell to update the value of this cell.

  Returns MutCell<T2>

  Example

  const a = bind(1);
  const b = a.bimap(x => x + 1, y => y - 1);
  
  expect(b.value).toBe(2);
  
  a.value = 5;
  expect(b.value).toBe(6);
  
  b.value = 3;
  expect(a.value).toBe(2);
  Copy

blur

• blur(): void

  Returns void

cached

• cached(): Cell<number>

  Returns Cell<number>

eq

• eq<T2 extends undefined | number>(other: T2 | Cell<T2>): Cell<boolean>

  Create a cell tthe value of which is true if this cell's value is equal to the given value or the value of the given cell, false otherwise.

  Type Parameters

  • T2 extends undefined | number

  Parameters

  • other: T2 | Cell<T2>

    A value or cell to compare the value of this cell to.

  Returns Cell<boolean>

  A cell.

flatMap

• flatMap<T2>(f: (value: number) => Cell<T2>): Cell<T2>

  Create a cell that applies a function to the value of this cell. The function must return a cell.

  Type Parameters

  • T2

  Parameters

  • f: (value: number) => Cell<T2>

    The function apply to the cell value.

  Returns Cell<T2>

  A flat mapping cell.

focus

• focus(): void

  Returns void

getAndObserve

• getAndObserve(observer: CellObserver<number>): () => void

  Get the cells current value and attach an observer. The observer function is called once with the current value immediately upon calling this method.

  The observer is attached before it's called with the current value of the cell.

  Parameters

  • observer: CellObserver<number>

    The observer function to attach.

  Returns () => void

  A function that can be called to detach the observer. Alternatively unobserve can be called.

map

• map<T2>(f: (value: number) => T2): Cell<T2>

  Create a cell that applies a function to the value of this cell.

  The function will be called whenever the value property of the resulting cell is accessed. If the resulting cell is being observed, the function will also be called once each time the value of this cell changes.

  Type Parameters

  • T2

  Parameters

  • f: (value: number) => T2

    The function to apply to the cell value.

  Returns Cell<T2>

  A cell.

mapDefined

• mapDefined<T2>(f: (value: number) => T2): Cell<undefined | T2>

  Create a cell that applies a function to the value of this cell, but only when the value is not null or undefined.

  The function will be called whenever the value property of the resulting cell is accessed. If the resulting cell is being observed, the function will also be called once each time the value of this cell changes.

  Type Parameters

  • T2

  Parameters

  • f: (value: number) => T2

    The function apply to the cell value.

  Returns Cell<undefined | T2>

  A mapping cell.

observe

• observe(observer: CellObserver<number>): () => void

  Attach an observer.

  Parameters

  • observer: CellObserver<number>

    The observer function to attach.

  Returns () => void

  A function that can be called to detach the observer. Alternatively unobserve can be called.

or

• or<T2>(other: Cell<T2>): Cell<number | T2>

  Type Parameters

  • T2

  Parameters

  • other: Cell<T2>

  Returns Cell<number | T2>

orElse

• orElse(alternative: number): Cell<number>

  Parameters

  • alternative: number

  Returns Cell<number>

toPromise

• toPromise(): Promise<number>

  Create a promise that resolves with the first non-null, non-undefined value of this cell. If the value of this cell is not null or undefined the method returns a resolved Promise with the value.

  Returns Promise<number>

  A promise that resolves when the value of this cell is not null or undefined.

unobserve

• unobserve(observer: CellObserver<number>): void

  Detach an observer.

  Parameters

  • observer: CellObserver<number>

    The observer function to detach.

  Returns void

update

• update<T2>(mutator: (value: number) => T2): T2

  Update the cell's value via a function.

  Type Parameters

  • T2

  Parameters

  • mutator: (value: number) => T2

    A function that modifies the value of this cell.

  Returns T2

  If the mutator function returns a value, that value is returned by update as well.

  Example

  const a = cell({b: 5});
  a.update(a => a.b = 10);
  expect(a.value.b).toBe(10);
  Copy

updateDefined

• updateDefined<T2>(mutator: (value: number) => T2): undefined | T2

  Same as update but the function is only applied if the value of the cell is not null or undefined.

  Type Parameters

  • T2

  Parameters

  • mutator: (value: number) => T2

  Returns undefined | T2

Staticfrom

• from<T>(observable: Observable<T>, initialValue: T): Cell<T>

  Create a cell from an existing observable (e.g. an Emitter) and an initial value.

  N.B. Unless observed, the value of the resulting cell will not update when the observable emits events.

  Type Parameters

  • T

  Parameters

  • observable: Observable<T>

    An observable.
  • initialValue: T

    The initial value of the cell.

  Returns Cell<T>

  A cell.