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Re: Bind custom function to the all Function objects

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Stefan Ram wrote:

> ram@zedat.fu-berlin.de (Stefan Ram) writes:
>>"use strict";
> 
>   The next version instruments more different functions.
> 
>   It does not try to instrument the console object. As this
>   is used for debugging purposes within the instrumented
>   functions, instrumenting it might cause infinite recursion.

But is is augmenting the object referred to by “console.log”, a callable 
property of a host object.  That is a Really Bad Idea.  (And for what?)
 
> "use strict";
> 
> const global = this;
> 
> function main()
> { "use strict";

If the global code is strict code, the function code is automatically strict 
code (strict mode cannot be undone for security reasons).  So this 
declaration is unnecessary.
 
> […]
>   const enumerate = function( path, object )
>   { "use strict";
>     if( typeof global.Object.getOwnPropertyNames === "function" )
                 ^^^^^^
This *closure* is unnecessary if you do not amok-code and start declaring 
“Object” locally (or expect this from others; but the way you write code,
I can see how that expectation might easily come to your mind).

There is also no performance advantage in this because the scope chain needs 
to be consulted either way.  There is a clear performance disadvantage 
because an extra property lookup for “global” needs to take place.  An 
explicit reference to the global object should only be used if absolutely 
necessary.  Also it makes sense to cache references locally, because the 
scope chain is shorter then, which increases runtime efficiency.

>     { const key = global.Object.getOwnPropertyNames( object );
>       const keyLength = key.length;
>       for( let i = 0; i < keyLength; ++i )

The “let” keyword is not specified in the current standard, ECMAScript 5.1 
Edition.  (Neither is the “const” keyword.)  AFAIK, it is supported by 
Mozilla JavaScript only; earlier versions only supported it if your declared 
version 1.7 by “type” attribute of the “script” element.

Code posted here should be written according to the standard (Ed. 3 and 
later), for a reasonable level of compatibility.  Implementation-specific or 
experimental features should be either avoided or clearly documented as 
such.

> […]
>   global.Object.getOwnPropertyNames.wasInstrumented20140618032449 =
>   global.Object.wasInstrumented20140618032449 =
>   global.Date.wasInstrumented20140618032449 =
>   global.Number.wasInstrumented20140618032449 =
>   global.String.wasInstrumented20140618032449 =
>   global.Boolean.wasInstrumented20140618032449 =
>   global.Function.wasInstrumented20140618032449 =
>   global.console.log.wasInstrumented20140618032449 =

I do not think it is a good idea to refer to “console” as property of the 
global object of one particular global execution context.

Instead of copy-pasting the ID, one should reuse a constant-like value like 
this:

  Object.getOwnPropertyNames[INSTRUMENTAL_PROPERTY] = true;

I find it curious that you appear to be using the not backwards-compatible 
“const” keyword for anything but true constants.

Finally, your code style is still hard to read, to say the least.
For example, using a loop is indicated here instead of multiple nested 
assignments:

  for (var a = [["Object", "getOwnPropertyName"], "Object", "Date",
                "Number", "String", "Boolean", "Function"],
           i = a.length;
       i--;)
  {
    var p = a[i];

    if (Array.isArray(p))
    {
      global[p[0]][p[1]][INSTRUMENTED_PROPERTY] = true;
    }
    else
    {
      global[p][INSTRUMENTED_PROPERTY] = true;
    }
  }

The very least you should do is to indent nested assignments.

-- 
PointedEars
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Thread

Bind custom function to the all Function objects Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-06-13 16:32 +0200
  Re: Bind custom function to the all Function objects Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-13 16:56 +0200
    Re: Bind custom function to the all Function objects Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-06-13 17:21 +0200
      Re: Bind custom function to the all Function objects "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-06-13 08:39 -0700
      Re: Bind custom function to the all Function objects Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-13 19:01 +0200
        Re: Bind custom function to the all Function objects Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-06-13 22:41 +0200
          Re: Bind custom function to the all Function objects Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-14 01:57 +0200
            Re: Bind custom function to the all Function objects Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-14 15:55 +0200
            Re: Bind custom function to the all Function objects Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-06-16 21:55 +0200
              Re: Bind custom function to the all Function objects Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-16 23:26 +0200
  Re: Bind custom function to the all Function objects Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-18 21:04 +0200

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