Class Flags<K>

derive

• derive(this: Cell<number>, fn: (v: number) => number): this

  Read-only same-type view: the RO dual of the endo .lens. For a cross-type view use the typed static Target.derive(src, fn).

  Parameters

  • this: Cell<number>
  • fn: (v: number) => number

  Returns this

lens

• lens(
      this: Cell<number>,
      fwd: (v: number) => number,
      bwd: (target: number, current: number) => number,
  ): this

  Endomorphic lens from a fwd/bwd pair (2-arg bwd reads the source, 1-arg reconstructs it), or apply optic value(s), chaining left-to-right. A chain whose every hop is T → T stays same-type (returns this); a chain that changes the value type yields a plain Cell of the final view.

  Parameters

  • this: Cell<number>
  • fwd: (v: number) => number
  • bwd: (target: number, current: number) => number

  Returns this

• lens(
      this: Cell<number>,
      ...optics: readonly AppliedOptic<number, number>[],
  ): this

  Endomorphic lens from a fwd/bwd pair (2-arg bwd reads the source, 1-arg reconstructs it), or apply optic value(s), chaining left-to-right. A chain whose every hop is T → T stays same-type (returns this); a chain that changes the value type yields a plain Cell of the final view.

  Parameters

  • this: Cell<number>
  • ...optics: readonly AppliedOptic<number, number>[]

  Returns this

• lens<V1>(
      this: Cell<number>,
      optic: AppliedOptic<number, V1>,
  ): Writable<Cell<V1>>

  Endomorphic lens from a fwd/bwd pair (2-arg bwd reads the source, 1-arg reconstructs it), or apply optic value(s), chaining left-to-right. A chain whose every hop is T → T stays same-type (returns this); a chain that changes the value type yields a plain Cell of the final view.

  Type Parameters

  • V1

  Parameters

  • this: Cell<number>
  • optic: AppliedOptic<number, V1>

  Returns Writable<Cell<V1>>

• lens<Os extends AnyOptics>(
      this: Cell<number>,
      ...optics: Os,
  ): Writable<Cell<ChainResult<number, Os>>>

  Endomorphic lens from a fwd/bwd pair (2-arg bwd reads the source, 1-arg reconstructs it), or apply optic value(s), chaining left-to-right. A chain whose every hop is T → T stays same-type (returns this); a chain that changes the value type yields a plain Cell of the final view.

  Type Parameters

  • Os extends AnyOptics

  Parameters

  • this: Cell<number>
  • ...optics: Os

  Returns Writable<Cell<ChainResult<number, Os>>>

merge

• merge(this: Cell<number>, fold?: MergeFold<number>): Cell<number>

  Backward fan-in: forwards its parent's value unchanged; on write, folds N contributors into one value. fold defaults to last-writer-wins.

  Parameters

  • this: Cell<number>
  • Optionalfold: MergeFold<number>

  Returns Cell<number>

peek

• peek(): number

  Returns number

Staticcoerce

• coerce<C extends AnyCellCtor>(
      this: C,
      v: Val<Inner<InstanceType<C>>>,
  ): InstanceType<C>

  Coerce Val<Inner<Cls>> → Cls: instance → identity, RO cell → tracked derive, literal → fresh seed.

  Type Parameters

  • C extends AnyCellCtor

  Parameters

  • this: C
  • v: Val<Inner<InstanceType<C>>>

  Returns InstanceType<C>

Staticderive

• derive<C extends AnyCellCtor, P>(
      this: C,
      parent: Read<P>,
      fn: (v: P) => Inner<InstanceType<C>>,
  ): InstanceType<C>

  Read-only typed view. Cls.derive(parent, fn) (1-input), Cls.derive(parents, fn) (N-input), or Cls.derive(fn) (closure). Polymorphic-this: Vec.derive(...) → Vec.

  Type Parameters

  • C extends AnyCellCtor
  • P

  Parameters

  • this: C
  • parent: Read<P>
  • fn: (v: P) => Inner<InstanceType<C>>

  Returns InstanceType<C>

• derive<C extends AnyCellCtor, P extends readonly Read<unknown>[]>(
      this: C,
      parents: P,
      fn: (vals: ReadValues<P>) => Inner<InstanceType<C>>,
  ): InstanceType<C>

  Read-only typed view. Cls.derive(parent, fn) (1-input), Cls.derive(parents, fn) (N-input), or Cls.derive(fn) (closure). Polymorphic-this: Vec.derive(...) → Vec.

  Type Parameters

  • C extends AnyCellCtor
  • P extends readonly Read<unknown>[]

  Parameters

  • this: C
  • parents: P
  • fn: (vals: ReadValues<P>) => Inner<InstanceType<C>>

  Returns InstanceType<C>

• derive<C extends AnyCellCtor>(
      this: C,
      fn: () => Inner<InstanceType<C>>,
  ): InstanceType<C>

  Read-only typed view. Cls.derive(parent, fn) (1-input), Cls.derive(parents, fn) (N-input), or Cls.derive(fn) (closure). Polymorphic-this: Vec.derive(...) → Vec.

  Type Parameters

  • C extends AnyCellCtor

  Parameters

  • this: C
  • fn: () => Inner<InstanceType<C>>

  Returns InstanceType<C>

Staticis

• is<C extends AnyCellCtor>(this: C, v: unknown): v is InstanceType<C>

  Type predicate against this class: Vec.is(x) narrows x to Vec. Inherited static; works for any subclass via polymorphic this.

  Type Parameters

  • C extends AnyCellCtor

  Parameters

  • this: C
  • v: unknown

  Returns v is InstanceType<C>

Staticlens

• lens<C extends AnyCellCtor, P>(
      this: C,
      parent: Read<P>,
      fwd: (v: P) => Inner<InstanceType<C>>,
      bwd: (target: Inner<InstanceType<C>>, v: P) => P,
  ): Writable<InstanceType<C>>

  Writable lens, typed to this class. Cls.lens(parent, fwd, bwd) for one input, Cls.lens(parents, fwd, bwd) for N (a 2-arg bwd reads the source, a 1-arg bwd reconstructs it); Cls.lens(parent(s), optic, …) applies an optic value (pure or complement-carrying), chaining left-to-right onto this class.

  Type Parameters

  • C extends AnyCellCtor
  • P

  Parameters

  • this: C
  • parent: Read<P>
  • fwd: (v: P) => Inner<InstanceType<C>>
  • bwd: (target: Inner<InstanceType<C>>, v: P) => P

  Returns Writable<InstanceType<C>>

• lens<C extends AnyCellCtor, P extends readonly Read<unknown>[]>(
      this: C,
      parents: P,
      fwd: (vals: ReadValues<P>) => Inner<InstanceType<C>>,
      bwd: (
          target: Inner<InstanceType<C>>,
          vals: ReadValues<P>,
      ) => BackUpdates<ReadValuesOrSkip<P>>,
  ): Writable<InstanceType<C>>

  Writable lens, typed to this class. Cls.lens(parent, fwd, bwd) for one input, Cls.lens(parents, fwd, bwd) for N (a 2-arg bwd reads the source, a 1-arg bwd reconstructs it); Cls.lens(parent(s), optic, …) applies an optic value (pure or complement-carrying), chaining left-to-right onto this class.

  Type Parameters

  • C extends AnyCellCtor
  • P extends readonly Read<unknown>[]

  Parameters

  • this: C
  • parents: P
  • fwd: (vals: ReadValues<P>) => Inner<InstanceType<C>>
  • bwd: (
        target: Inner<InstanceType<C>>,
        vals: ReadValues<P>,
    ) => BackUpdates<ReadValuesOrSkip<P>>

  Returns Writable<InstanceType<C>>

• lens<C extends AnyCellCtor, P>(
      this: C,
      parent: Read<P>,
      optic: AppliedOptic<P, Inner<InstanceType<C>>>,
  ): Writable<InstanceType<C>>

  Writable lens, typed to this class. Cls.lens(parent, fwd, bwd) for one input, Cls.lens(parents, fwd, bwd) for N (a 2-arg bwd reads the source, a 1-arg bwd reconstructs it); Cls.lens(parent(s), optic, …) applies an optic value (pure or complement-carrying), chaining left-to-right onto this class.

  Type Parameters

  • C extends AnyCellCtor
  • P

  Parameters

  • this: C
  • parent: Read<P>
  • optic: AppliedOptic<P, Inner<InstanceType<C>>>

  Returns Writable<InstanceType<C>>

• lens<C extends AnyCellCtor, P extends readonly Read<unknown>[]>(
      this: C,
      parents: P,
      optic: AppliedOptic<ReadValues<P>, Inner<InstanceType<C>>>,
  ): Writable<InstanceType<C>>

  Writable lens, typed to this class. Cls.lens(parent, fwd, bwd) for one input, Cls.lens(parents, fwd, bwd) for N (a 2-arg bwd reads the source, a 1-arg bwd reconstructs it); Cls.lens(parent(s), optic, …) applies an optic value (pure or complement-carrying), chaining left-to-right onto this class.

  Type Parameters

  • C extends AnyCellCtor
  • P extends readonly Read<unknown>[]

  Parameters

  • this: C
  • parents: P
  • optic: AppliedOptic<ReadValues<P>, Inner<InstanceType<C>>>

  Returns Writable<InstanceType<C>>

• lens<C extends AnyCellCtor, P, Os extends AnyOptics>(
      this: C,
      parent: Read<P>,
      ...optics: Os,
  ): ChainResult<P, Os> extends Inner<InstanceType<C>>
      ? Writable<InstanceType<C>>
      : never

  Writable lens, typed to this class. Cls.lens(parent, fwd, bwd) for one input, Cls.lens(parents, fwd, bwd) for N (a 2-arg bwd reads the source, a 1-arg bwd reconstructs it); Cls.lens(parent(s), optic, …) applies an optic value (pure or complement-carrying), chaining left-to-right onto this class.

  Type Parameters

  • C extends AnyCellCtor
  • P
  • Os extends AnyOptics

  Parameters

  • this: C
  • parent: Read<P>
  • ...optics: Os

  Returns ChainResult<P, Os> extends Inner<InstanceType<C>>
      ? Writable<InstanceType<C>>
      : never

• lens<
      C extends AnyCellCtor,
      P extends readonly Read<unknown>[],
      Os extends AnyOptics,
  >(
      this: C,
      parents: P,
      ...optics: Os,
  ): ChainResult<ReadValues<P>, Os> extends Inner<InstanceType<C>>
      ? Writable<InstanceType<C>>
      : never

  Writable lens, typed to this class. Cls.lens(parent, fwd, bwd) for one input, Cls.lens(parents, fwd, bwd) for N (a 2-arg bwd reads the source, a 1-arg bwd reconstructs it); Cls.lens(parent(s), optic, …) applies an optic value (pure or complement-carrying), chaining left-to-right onto this class.

  Type Parameters

  • C extends AnyCellCtor
  • P extends readonly Read<unknown>[]
  • Os extends AnyOptics

  Parameters

  • this: C
  • parents: P
  • ...optics: Os

  Returns ChainResult<ReadValues<P>, Os> extends Inner<InstanceType<C>>
      ? Writable<InstanceType<C>>
      : never

Staticpin

• pin<C extends AnyCellCtor>(
      this: C,
      v: Inner<InstanceType<C>>,
  ): Writable<InstanceType<C>>

  Writable-shaped constant: always reads v, absorbs writes (parentless sink lens), for APIs demanding bidirectionality.

  Type Parameters

  • C extends AnyCellCtor

  Parameters

  • this: C
  • v: Inner<InstanceType<C>>

  Returns Writable<InstanceType<C>>

name

Readonlyvalue