JEP325: Switch expressions spec
forax at univ-mlv.fr
forax at univ-mlv.fr
Mon Apr 23 19:07:13 UTC 2018
'->' being a two characters symbol (at least if you do not enable font ligature of your IDE/editor) is a more strong separator than comma ',',
so i think it's easy to visually parse
case pat1, pat2 -> s
as
case [pat1, pat2] -> s
than
case pat1, [pat2 -> s]
Rémi
----- Mail original -----
> De: "Guy Steele" <guy.steele at oracle.com>
> À: "Remi Forax" <forax at univ-mlv.fr>
> Cc: "amber-spec-experts" <amber-spec-experts at openjdk.java.net>
> Envoyé: Lundi 23 Avril 2018 20:32:26
> Objet: Re: JEP325: Switch expressions spec
>> On Apr 23, 2018, at 2:27 PM, Guy Steele <guy.steele at oracle.com> wrote:
>>
>> Good point, Rémi. However, note that
>>
>> case pat1, pat2 -> s
>>
>> is equally too close to
>>
>> case pat1 -> pat2 -> s
>>
>> and again they have very different meanings.
>>
>> We have to admit that there is room to blunder with this syntax.
>>
>> One way out would be to use a different arrow for `switch` statements:
>>
>> switch (x) {
>> case pat1 => case pat2 => s1;
>> case pat3 => pat4 -> s2;
>> case pat5, pat6 => s2;
>> case pat7, pat8 => pat9 -> s4;
>> }
>
> As a careful coder, if I did not have a separate arrow `=>` (and probably even
> if I did), I would use formatting and parentheses to convey my intent:
>
> switch (x) {
> case pat1 ->
> case pat2 -> s1;
> case pat3 -> (pat4 -> s2);
> case pat5, pat6 -> s2;
> case pat7, pat8 -> (pat9 -> s4);
> }
>
> —Guy
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