please add orEqual operator

[Andrea Giammarchi]

On Mon, Aug 10, 2015 at 5:42 PM, joe <joeedh at gmail.com> wrote:

> Isn't this what switch statements are for?  Perhaps a condensed operator
> version of a switch would be useful?
>
>     if (a == 0 : 1 : 2) {
>     }
>

switch does eqeqeq comparison so is not exactly the same
`switch(1) { case true: console.log('never'); }`



>
> Or perhaps something similar to the set version, but without the set:
>
>     if (a of 1, 2, 3, 4, 5, 6) {
>     }
>


an `if/of` doesn't feel that right to me ... weird semantic

`[1, 2, 3, 4, 5, 6].contains(a)` looks better ?




>
> One could do this as a standard lib variadic function, I suppose:
>
>     if (select(a, 1, 2, 3, 4, 5, 6)) {
>     }
>
>
No, the main  point of having operators is that the engine could just skip
the fallback part.


`var a = 1 || doSomethingComplex(123)`

as example, will never execute doSomethingComplex whilc passing any value
as argument should be already resolved as value.



In any case, FWIW, I think this is a classic "nostalgia operator" asked
from someone that uses from another PL or just started using JS ... I
wouldn't mind some well integrated and well thought shortcut, but I feel
like this should be the least priority for ES.next

Best Regards





>
> Cheers,
> Joe
>
> On Mon, Aug 10, 2015 at 6:09 AM, <myemailum14 at gmail.com> wrote:
>
>> Thanks I'll be searching through archive, and yea i think this is
>> something very simple and yet innovative.
>>
>> On Mon, Aug 10, 2015 at 3:55 AM, Peter van der Zee <ecma at qfox.nl> wrote:
>>
>>> On Mon, Aug 10, 2015 at 3:50 AM,  <myemailum14 at gmail.com> wrote:
>>> > Isn't
>>> > prop ||= 0;
>>> > better than
>>> > prop = prop || 0;
>>> > and it can be even defined like this.
>>> > prop ||= var1 ||= var2 ||= 0;
>>> > but then i dont know how we can use it ike this
>>> > if (num == 3 ||=4 ||=6)
>>>
>>> Sounds like you want two operators; `||=` for the compound assignment
>>> case and `||==` and `||===` for the "compare the RHS to the LHS of the
>>> last `===` or `==` op", or something like that. Defining a single op
>>> for both of these cases is likely to lead to ambiguity.
>>>
>>> The `||=` (and `&&=`) case has been discussed a couple of times, look
>>> in the esdiscuss archives.
>>> I'm sure something like `||==` has been discussed too though I don't
>>> recall it myself. I tend to use switches myself for this in case perf
>>> is an issue.
>>>
>>> - peter
>>>
>>
>>
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>
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