Syntax to get same object that method was called on (Easy method chaining)

[Caitlin Potter]

I think, if you were going to have this, it would be best if bound `this` were ignored, and if it were a syntax error for non-property references.

Reason being, you'd actually be able to tell what was going on, mostly, by reading the source code. Otherwise it's really hard to tell what's going on.

A more interesting question could be super properties, since the appropriate receiver isn't the same as the object the method is looked up on

```js
super
  .foo()
  .bar(); // overridden bar or superclass bar?
```

Dart has something like this, do they have weird rules about `this` to work around too?

> On Oct 26, 2015, at 12:46 AM, Edwin Reynoso <eorroe at gmail.com> wrote:
> 
> `foo()#` this one it depends, how `foo` is defined
> 
> if `foo` is defined in the `window` scope, it'll return the `window`:
> 
> if not and just like this in another scope, it should most likely throw:
> 
> ```
> (function() {
>  function foo() {};
>  foo()# // throws
> })();
> ```
> 
> `foo.bar.call(baz)#` would return `baz` because
> 
> > (basically the `this` value of the method call)
> 
> `baz.quux = foo.bind(bar)`, that's something that I'm not sure what's best, so not sure, but because of what I said above I think the right answer would be to return `bar` (the `this` value)
> 
> `[].length#` will return the array
> 
> `{ foo: 3 }.foo#` same thing as above, it'll return the object
> 
>> On Mon, Oct 26, 2015 at 12:34 AM, Jordan Harband <ljharb at gmail.com> wrote:
>> This immediately raises some questions for me: 
>>  - what would `foo()#` return? (a bare function call - the question applies to strict mode, and sloppy mode)
>>  - what would `foo.bar.call(baz)#` return? (foo? or baz?)
>>  - what would `baz.quux = foo.bind(bar); baz.quux()#` return? (baz? or bar?)
>>  - what would `[].length#` return? (an accessor property) (throw? the array? undefined?)
>>  - what would `{ foo: 3 }.foo#` return? (a data property) (throw? the object? undefined?)
>> 
>>> On Sun, Oct 25, 2015 at 9:25 PM, Edwin Reynoso <eorroe at gmail.com> wrote:
>>> Could we get a way to basically to get the object back from after a method was called, so that instead of this:
>>> 
>>> ```JS
>>> let obj = {
>>>  doSomething() {
>>>    // some side effect
>>>    return 5;
>>>  },
>>>  doSomething2() {
>>>    // some other side effect
>>>    return {x: 5}; 
>>>  }
>>> }
>>> 
>>> obj.doSomething();
>>> obj.doSomething2();
>>> ```
>>> 
>>> We could do this:
>>> ```
>>> obj.doSomething()#doSomething2();
>>> ```
>>> 
>>> Where `#` gets the object that the method was called on (basically the `this` value of the method call)
>>> 
>>> Why?
>>> 
>>> There are lots of methods that don't return anything (they return `undefined` by default) and instead of retyping the same object we could have `#` give us the object back. There's also methods that do return something but I may not want that value:
>>> 
>>> ```
>>> let arr = [1,2,3];
>>> arr.push(4).forEach(function() {...}); // throws because the push method returns the length of the array
>>> ```
>>> With `#` I could do:
>>> 
>>> ```
>>> arr.push(4)#forEach(function() {...});
>>> ```
>>> 
>>> Ayy even `forEach` itself doesn't return, there's a [discussion](https://esdiscuss.org/topic/return-value-of-foreach) on changing that instead of breaking APIs which we can't we can have this:
>>> 
>>> ```
>>> arr.push(4)#forEach(function() {...});
>>> ```
>>> 
>>> which won't require any API changes, and could be used on any function.
>>> 
>>> Now I have no idea about implementation details, so not sure if this is possible
>>> 
>>> thoughts?
>>> 
>>> _______________________________________________
>>> es-discuss mailing list
>>> es-discuss at mozilla.org
>>> https://mail.mozilla.org/listinfo/es-discuss
> 
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