Rhino JavaScript 和动态作用域变量创建

发布于 2024-08-20 04:00:28 字数 616 浏览 9 评论 0原文

我试图在 Rhino JavaScript 的函数中定义动态变量（特别是 Java 6 中嵌入的变量），但我不想诉诸 eval，也不想通过 this 引用它。基本上，我想获取一个对象，并将每个属性都转换为函数范围内的 var...类似：

var abc = "value";
var context = { abc: 123, xyz: "def" };

function test(cx) {
  for (var p in cx) {
    this_scope[p] = cx[p];
  }

  println(abc);
  // DON'T WANT TO HAVE TO DO THIS:
  // pritnln(this.abc);
}

test(context); // prints: 123
println(abc); // prints: value

不管你相信与否，如果我必须使用“this”，那就很重要了。（它是一个动态生成的函数，我想用不同的上下文对象一遍又一遍地调用它，并且对每个变量使用“this”将非常有害）。

我还想避免必须获取新的引擎上下文或类似的东西...如果我可以直接在 JavaScript 中执行此操作，那就太好了（我认为结果会明显更快）。

原文

I am trying to define a dynamic variable within a function in Rhino JavaScript (specifically what is embedded in Java 6), but I don't want to resort to eval, and I don't want to have to reference it via this. Basically, I want to take an object, and turn every property into a var within the scope of a function... something like:

var abc = "value";
var context = { abc: 123, xyz: "def" };

function test(cx) {
  for (var p in cx) {
    this_scope[p] = cx[p];
  }

  println(abc);
  // DON'T WANT TO HAVE TO DO THIS:
  // pritnln(this.abc);
}

test(context); // prints: 123
println(abc); // prints: value

Believe it or not, it is significant if I have to use "this." (it is a dynamically generated function that I want to invoke over and over with different context objects and using "this" for every variable would be very detrimental).

I also want to avoid having to grab a new engine context or something like that... it would be superb if I can do this straight in JavaScript (I think the result would be significantly faster).

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望笑 2024-08-27 04:00:28

那么，基本上你想要像 JS 的 with 一样工作的东西吗？ *咧嘴笑，躲开，然后跑*

var abc = "value";
var context = {abc: 123, xyz: "def"};

function test(cx) {
    with (cx) {
        println(abc);
    }
}

test(context);
println(abc);

请注意，一些著名的 JS 从业者，例如 Doug Crockford，强烈反对使用 with。

So, basically you want something that works like JS's with? *grins, ducks, and runs*

var abc = "value";
var context = {abc: 123, xyz: "def"};

function test(cx) {
    with (cx) {
        println(abc);
    }
}

test(context);
println(abc);

Mind you, some well-known JS practitioners, like Doug Crockford, strongly deprecate the use of with.

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