具有可变数量/参数类型的函数的TypeScript声明文件 [英] TypeScript declaration file for function with variable number/type of arguments

问题描述

headjs在其API上做了一些非常疯狂的JavaScript类型的事情。例如，它为函数接受任意数量的字符串（不是字符串数组）。有时它会结束相同的函数调用，例如，你可以选择以函数结束它。

headjs does some very crazy JavaScript type things to its API. For instance it takes an arbitrary number of strings (not a string array) for a function. Sometimes it ends that same function call, you can optionally end it with a function, for example.

head.js("scripturl1", "scripturl2",...,callback);

您也可以（同样容易）执行以下操作

You can also (just as easily) do the following

head.js({scriptlabel:"scripturl1"},{scriptlabel2:"scripturl2"},...., callback);

我的问题是我们如何在声明文件中描述HECK？由于我当前的传递似乎完全错误，所以我全都听到了。

My question is how the HECK do we describe that in a declaration file? I am all ears here as my current pass seems completely wrong.

推荐答案

TS语言规范将变量数/传播参数称为休息参数。具有接受休息参数的函数签名的示例接口：

The TS language spec refers to variable number/spread parameters as "Rest Parameters". An example interface with a function signature that accepts rest params:

interface IExample {
    fn : (...args : any[]) => any;
}

var x : IExample = {
    fn: function(...args : any[]) {
        for (var i = 0, arg; arg = args[i]; i++) {
            console.log(arg);
        }
    }
}

x.fn(1);
x.fn(1, 2);
x.fn("cat", "dog", "mouse");

不幸的是，存在一些限制。 Rest Parameter必须是函数签名中的最后一个 - 因此您将无法捕获回调参数的类型，因为它位于重复参数之后。

Unfortunately, there are some limitations. The "Rest Parameter" has to be the last one in a function's signature -- so you won't be able to capture the type of the callback parameter since it is after the repeating parameter.

如果不是，你可以这样做：

If it wasn't, you would have been able to do something like this:

var fn = function(cb: Function, ...args : string[]) {
    ...
}

这篇关于具有可变数量/参数类型的函数的TypeScript声明文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！