Re: Object.create(canvas.getContext())

From	Jan Bruns <ebay@abnuto.de>
Newsgroups	comp.lang.javascript
Subject	Re: Object.create(canvas.getContext())
Date	2017-11-20 14:47 +0000
Organization	MB-NET.NET for Open-News-Network e.V.
Message-ID	<ouuptf$59b$1@gwaiyur.mb-net.net> (permalink)
References	(3 earlier) <1754058.usQuhbGJ8B@PointedEars.de> <oungju$hmt$1@gwaiyur.mb-net.net> <10957516.O9o76ZdvQC@PointedEars.de> <oustnb$gbb$1@gwaiyur.mb-net.net> <4026723.LvFx2qVVIh@PointedEars.de>

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Thomas 'PointedEars' Lahn:
> Jan Bruns wrote:
> 

>>> For example, there is a reason why I enclosed the host object property
>>> access in a “try” block.

>> What is that reason? Does "typeof" throw on any enumerated property
>> anywhere?

> If you would have tried, you would have seen that
> 
>   typeof Object.getPrototypeOf(webGLcontext)[name] == "function"
> 
> throws “TypeError: Illegal invocation” for the _enumerable_ properties
> where

Interesting. Saved me from thinking about how to create an object that 
throws on typeof(enumerated property). Maybe the "getters" can do so.

But we're talking about a very popular API, meaning there are thousands 
or maybe even a million programmers out there that tried out or will try 
out working with it.

The prototype object of such an API of course might have very browser 
specific behaviour that isn't spcificly user friendly (and even doesn't 
necessarily have to meet programing language specific functionality), as 
long as the API's specification doesn't explicitly define such behaviour.

But if 

for (var i in API) { typeof API[i] };

would throw, why did they implement and enumerate that fail?

Well, probably for the same reasons, as 

Object.create(API);

might not work as expected: work in progress.

But then, the only clean way to deal with it would be to copy&paste the 
API specification (like C headers) to any project that needs to inherit 
the API instead of just referencing it. I'll probably do that in case I 
see a problem that could be solved that way, but work in progress...

Gruss

Jan Bruns

Thread

Object.create(canvas.getContext()) Jan Bruns <ebay@abnuto.de> - 2017-11-12 10:09 +0000
  Re: Object.create(canvas.getContext()) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-11-12 17:42 +0100
    Re: Object.create(canvas.getContext()) Jan Bruns <ebay@abnuto.de> - 2017-11-14 11:48 +0000
      Re: Object.create(canvas.getContext()) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-11-15 02:32 +0100
        Re: Object.create(canvas.getContext()) Jan Bruns <ebay@abnuto.de> - 2017-11-17 20:25 +0000
          Re: Object.create(canvas.getContext()) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-11-19 05:48 +0100
            Re: Object.create(canvas.getContext()) Jan Bruns <ebay@abnuto.de> - 2017-11-19 21:39 +0000
              Re: Object.create(canvas.getContext()) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-11-19 23:34 +0100
                Re: Object.create(canvas.getContext()) Jan Bruns <ebay@abnuto.de> - 2017-11-20 14:47 +0000
                Re: Object.create(canvas.getContext()) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-11-21 04:07 +0100
                Re: Object.create(canvas.getContext()) Jan Bruns <ebay@abnuto.de> - 2017-11-21 16:23 +0000
                Re: Object.create(canvas.getContext()) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-11-22 04:12 +0100
  Re: Object.create(canvas.getContext()) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-11-12 18:45 +0100

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