原型如何在打字稿上扩展？ [英] How does prototype extend on typescript?

问题描述

我扩展了函数原型但是typescript无法识别它。

i extended function prototype but typescript doesn't recognize it.

Function.prototype.proc = function() {
  var args, target, v;
  var __slice = [].slice;
  args = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
  target = this;
  while (v = args.shift()) {
    target = target(v);
  }
  return target;
};
// generated by coffee-script

var foo: (number) => (string) => number
  = (a) => (b) => a * b.length;
console.log(foo.proc("first", "second"))

结果：tsc -e

The property 'proc' does not exist on value of type 'Function'

如何扩展此对象？

推荐答案

标准typescript lib中有一个Function接口，用于声明Function对象的成员。您将需要将proc作为该接口的成员与您自己的add一起声明如下：

There is a Function interface in the standard typescript lib which declares the members of Function objects. You will need to declare proc as a member of that interface with your own add on like the following:

interface Function {
    proc(...args: any[]): any;
}

此界面需要在您打算使用'proc'的任何地方引用。

This interface will need to be referenced from anywhere you intend to use 'proc'.

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