Re: Expression for the global object

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From	Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups	comp.lang.javascript
Subject	Re: Expression for the global object
Date	Sun, 31 May 2015 15:57:11 +0100
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Thomas 'PointedEars' Lahn <PointedEars@web.de> writes:

> Ben Bacarisse wrote:
>
>> (function () { return eval; })()("this")
>
> In all respects equivalent to
>
>   eval("this")
>
> which is equivalent to
>
>   this

Given:

  'use strict';
  console.log((function () { return eval; })()("this") === global);
  console.log(eval("this") === global);
  console.log(this === global);

nodejs prints:

  NaN
  undefined
  undefined

(global is nodejs specific, of course, but there are other simple ways
to test the value).

> which is why it does not return a reference to the global object, but the 
> “undefined” value, in strict function code that is not called as the method 
> of an object.
>
> <http://ecma-international.org/ecma-262/5.1/#sec-10.4.2>

Sure, but what does 15.1.2.1.1 (Direct Call to Eval) have to say about
it?  You can interpret the words there much more readily than I can, and
it would seem that at least one implementation has decided that the
evaluation of the thunk above is not a "direct call to eval".

-- 
Ben.

Thread

Re: Expression for the global object Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 11:14 +0100
  Re: Expression for the global object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-05-31 15:08 +0200
    Re: Expression for the global object Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 14:56 +0100
      Re: Expression for the global object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-05-31 16:12 +0200
        Re: Expression for the global object Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 15:57 +0100
          Re: Expression for the global object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-05-31 17:33 +0200
            Re: Expression for the global object Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 16:41 +0100
      Re: Expression for the global object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-05-31 16:21 +0200

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