> On 12 Mar 2021, at 11:02, Remi Forax <[email protected]> wrote:
>
> ----- Mail original -----
>> De: "Gavin Bierman" <[email protected]>
>> À: "John Rose" <[email protected]>
>> Cc: "amber-spec-experts" <[email protected]>
>> Envoyé: Vendredi 12 Mars 2021 11:11:46
>> Objet: Re: Guards redux
>
>> Thanks everyone for the discussion. I have updated the JEP:
>>
>> http://openjdk.java.net/jeps/8213076
>>
>> It proposes *guarded patterns* of the form `p&&e`, as well as parenthesized
>> patterns, written `(p)`.
>
>
> Hi Gavin,
> nice, i find this version more appealing.
Yay!
> In the first example that shows && as a guard, the example uses parenthesis
> which is my opinion should be removed
> case Triangle t && (t.calculateArea() > 100) ->
> System.out.println("Large Triangle");
>
> if i read the grammar correctly, those parenthesis around the boolean
> expression are unnecessary
> case Triangle t && t.calculateArea() > 100 ->
They are unnecessary, but this example comes before the grammar, so I didn’t
want anyone to get confused.
>
> it will be more inline with the example above in the text that is using 'when'
> case Triangle t when t.calculateArea() > 100 ->
>
>
> Otherwise, in the document, the words "->-style" and ":-style" are hard to
> parse, i think array-style and colon-style are better terms.
I’ll take a look.
> In the section "Dominance of pattern label",
> It's not clear to me if there is a dominance in between expressions,
> by example, can we have the following cases in that order ?
>
> case Foo(var a, var b) && a == 3:
> case Foo(var a, var b) && a == 3 && b == 4:
>
> for me the answer is yes, the dominance is computed on patterns only, not on
> expressions.
I agree. I don’t think trying to calculate dominance between expressions is
viable.
Thanks Rémi!
Gavin
