Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.javascript > #35344

Re: Recording changes to an object

Show key headers only | View raw

Michael Haufe (TNO) wrote:

> Thomas 'PointedEars' Lahn wrote:
>> There should be a *built-in* Object.clone() or Object.prototype.clone()
>> method that does this, but unfortunately there is not yet.  So user
>> libraries have to come to the rescue.
> 
> The issue here though is that an object is not simple a set of properties
> and methods. There is potentially, and probably, an associated state which
> is unobservable from outside the object (due to encapsulation).

Possible.  But that would not be a major problem: an object with special 
requirements could implement a clone() method method that is called by 
Object.clone() when it the object is about to be cloned:

  Object.clone = ((orig) => {
    if (orig.clone instanceof Function) return orig.clone();
 
    /* standard cloning */
  });

Compare JSON.stringify() which calls the toJSON() method of an object to be 
stringified if it has one.

> As such, Object.prototype.clone() is required instead of Object.clone(),
> otherwise you're simply making an "observable clone".

How did you get that idea?  Object.prototype.clone() would just be syntactic 
sugar:

  const CLONE = obj.clone();

instead of

  const CLONE = Object.clone(obj);

There is at least one other language that has a “clone” operator.  In ES it 
could be:

  const CLONE = clone obj;

For backwards compatibility it appears to be the best idea to have a native 
Object.clone().  Then name-safe polyfills can be provided, and the user has 
the freedom to override Object.prototype.clone() or override/define the 
clone() method of the target object or its other prototype.

Once/if backwards compatibility is not a concern (e.g. if it is Babel’d 
away), the “clone” operator could be used instead.
 
> Even so, the semantics of JavaScript would have to change as well in my
> estimation to support this more naturally. Specifically in regards to
> equality, the "new" operator, generators, and probably more.

I do not think so.
 
> Non trivial, but somewhat related is the recent research paper you might
> have seen:
> 
> <http://web.cecs.pdx.edu/~black/publications/egal.pdf>

Thanks, I will read it later.

-- 
PointedEars
FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
<https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.

Back to comp.lang.javascript | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Recording changes to an object Andrew Poulos <ap_prog@hotmail.com> - 2018-06-21 15:54 +1000
  Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 01:47 -0700
  Re: Recording changes to an object Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-06-21 17:01 +0100
    Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 09:48 -0700
      Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-06-22 09:58 +0100
  Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-06-21 21:03 +0200
    Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 16:25 -0700
    Re: Recording changes to an object Andrew Poulos <ap_prog@hotmail.com> - 2018-06-22 09:34 +1000
      Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 17:02 -0700
        Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 18:03 -0700
        Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-06-22 10:06 +0100
          Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-22 02:21 -0700
            Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-06-22 18:31 +0100
              Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-22 20:16 -0700
      Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-06-22 02:23 +0200
        Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 17:31 -0700
      Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-06-22 02:55 +0200
        Re: Recording changes to an object Andrew Poulos <ap_prog@hotmail.com> - 2018-06-22 12:37 +1000
          Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-22 02:23 -0700
            Re: Recording changes to an object Jake Jarvis <pig_in_shoes@yahoo.com> - 2018-06-22 14:35 +0200
              Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-22 05:57 -0700
                Re: Recording changes to an object Mickey Finn <mfinn@gmail.com> - 2018-06-22 15:43 -0300
              Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-06-22 13:51 +0200
                Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-22 06:04 -0700
                Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-06-22 18:33 +0100
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-06-24 14:36 +0200
                Re: Recording changes to an object "Mark-" <nospam@mapson.xyz> - 2018-06-24 13:56 +0000
                Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-06-25 10:06 +0100
                Re: Recording changes to an object Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-06-25 02:40 -0700
                Re: Recording changes to an object Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-06-25 02:47 -0700
                Re: Recording changes to an object Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-06-25 02:51 -0700
                Re: Recording changes to an object Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-06-25 02:54 -0700
                Re: Recording changes to an object Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-06-25 02:58 -0700
                Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-06-25 19:26 +0100
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-06-30 19:47 +0200
                Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-07-01 10:56 +0100
            Re: Recording changes to an object Andrew Poulos <ap_prog@hotmail.com> - 2018-06-23 17:19 +1000
              Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-23 00:51 -0700
                Re: Recording changes to an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-06-23 11:27 +0100
                Re: Recording changes to an object Andrew Poulos <ap_prog@hotmail.com> - 2018-06-23 20:59 +1000
                Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-23 05:51 -0700
    Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-06-30 19:43 +0200
      Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-01 15:22 +0200
        Re: Recording changes to an object Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2018-07-02 16:29 +0200
          Cloning an object (was: Recording changes to an object) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-04 23:25 +0200
            Re: Cloning an object Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2018-07-05 10:00 +0200
              Re: Cloning an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-05 19:49 +0200
                Re: Cloning an object Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2018-07-05 20:37 +0200
                Re: Cloning an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-05 23:35 +0200
                Re: Cloning an object Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2018-07-05 23:54 +0200
                Re: Cloning an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-06 00:32 +0200
                Re: Cloning an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-06 00:24 +0200
                Re: Cloning an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-07-06 18:48 +0100
                Re: Cloning an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-06 23:51 +0200
                Re: Cloning an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-07-07 15:51 +0100
                Re: Cloning an object Julio Di Egidio <julio@diegidio.name> - 2018-07-07 08:39 -0700
                Re: Cloning an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-07-09 10:20 +0100
                Re: Cloning an object Julio Di Egidio <julio@diegidio.name> - 2018-07-09 02:35 -0700
                Re: Cloning an object Julio Di Egidio <julio@diegidio.name> - 2018-07-09 02:41 -0700
                Re: Cloning an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-08 12:20 +0200
                Re: Cloning an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-07-08 14:38 +0100
                Re: Cloning an object Julio Di Egidio <julio@diegidio.name> - 2018-07-08 13:10 -0700
                Re: Cloning an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-07-09 09:48 +0100
                Re: Cloning an object Julio Di Egidio <julio@diegidio.name> - 2018-07-09 02:28 -0700
                Re: Cloning an object Julio Di Egidio <julio@diegidio.name> - 2018-07-09 02:38 -0700
                Re: Cloning an object John G Harris <niam@jghnorth.org.uk.invalid> - 2018-07-09 19:11 +0100
      Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-02 21:01 -0700
        Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-05 00:32 +0200
          Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-04 19:23 -0700
            Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-05 06:38 +0200
              Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-04 23:21 -0700
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-05 09:25 +0200
                Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-05 07:44 -0700
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-05 19:35 +0200
                Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-06 12:59 -0700
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-06 23:22 +0200
                Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-07 12:45 -0700
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-08 11:13 +0200
                Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-07-08 05:03 -0700
                Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-08 13:42 -0700
                Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-07-08 13:46 -0700
                Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-08 13:41 -0700
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-09 00:35 +0200
                Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-10 01:03 -0700
                Re: Recording changes to an object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-07-10 20:50 +0200
                Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-07-10 16:09 -0700
  Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-06-21 15:09 -0700
    Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 16:30 -0700
      Re: Recording changes to an object "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-06-21 16:57 -0700
        Re: Recording changes to an object Julio Di Egidio <julio@diegidio.name> - 2018-06-21 17:01 -0700

csiph-web