instance-callable

Create classes whose instances are callable.

Install

pnpm add instance-callable

Usage

Extend Callable and override [call].

import { call, Callable } from 'instance-callable'

class Counter extends Callable<[amount: number], number> {
  value = 0

  override [call](amount: number) {
    this.value += amount
    return this.value
  }
}

const counter = new Counter()

counter(2) // 2
counter(3) // 5
counter.value // 5

Function properties

Callable instances are functions. They retain the standard function members:

• name
• length
• prototype
• call
• apply
• bind
• arguments
• caller

Do not reuse these names for unrelated subclass fields or methods. Own function properties such as name, length, and prototype can block field assignment. Inherited methods such as call, apply, and bind can be shadowed and stop behaving like standard function methods. arguments and caller also have restricted legacy behavior.