[erlang-questions] Is it a compiler bug?

Robert Virding <>
Fri Apr 14 02:14:23 CEST 2017


IIRC originally parentheses were required around the first was required
which would have caught this case. The requirement was then removed, but I
don't know why. Perhaps to save the extra 2 chars. :-)


On 13 April 2017 at 16:43, Dmytro Lytovchenko <>
wrote:

> I can see how enforcing parentheses in map()map() syntax can be useful.
> A compiler warning would be awesome here. Also this is a nice thing for
> Elvis style checker to do, but when it comes to running Elvis, your program
> should already be correct — so that is too late.
>
> In variable()map() syntax there is no confusion so that is fine.
>
> 2017-04-13 16:14 GMT+02:00 Jesper Louis Andersen <
> >:
>
>> No, it is not stupidity in any way.
>>
>> People hit this now and again. It makes sense to solve the problem this
>> way. I remember we considered the alternative, which is to reject the
>> notion, but this requires some special-handling in the compiler and isn't
>> clear-cut either.
>>
>> In short, regarding this as an invalid expression is to a certain extent
>> possible, and certainly desirable. But we run into subtle problems when we
>> want to reject it too, which is what complicates matters.
>>
>> I think it is healthy to challenge certain design decisions in Erlang,
>> especially because dynamically typed languages tend to have corner cases in
>> their semantics which are hard to handle in general.
>>
>> On Thu, Apr 13, 2017 at 4:04 PM Minin Maxim <>
>> wrote:
>>
>>> I'm so stupid today J
>>>
>>> Thanks guys (Robert & Stanislaw)
>>>
>>> Cheers
>>>
>>> Maxim
>>>
>>>
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>>
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>
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