RFR 8144903: JShell: determine incorrectly the type of the expression which is array type of captured type

[ShinyaYoshida]

Oh... Certainly.
I've updated:
http://cr.openjdk.java.net/~shinyafox/kulla/8144903/webrev.05/

Thank you,
shinyafox(Shinya Yoshida)

2015-12-11 16:52 GMT+09:00 Robert Field <robert.field at oracle.com>:

>   91     public String visitClassType(ClassType ct, Locale locale) {  92         try {  93             useWildCard = true;  94             return super.visitClassType(ct, locale);  95         } finally {  96             useWildCard = false;  97         }  98     }
>
> I believe this could give wrong results because with nested class types you will be coming back to a case where useWildCard should still be true.
> The thing to do here is save the incoming value of the state you want to change (useWildCard) in a local variable, and restore it in the finally.
>
> -Robert
>
>
> On 12/10/15 14:13, ShinyaYoshida wrote:
>
> Hi Maurizio, Thank you.
>
> 2015-12-11 6:58 GMT+09:00 Maurizio Cimadamore <
> maurizio.cimadamore at oracle.com>:
>
>> Looks good, some comments:
>>
>> * watch out for the 'useWildcards' variable - you set it to true on the
>> first class you see, and you never reset it to false - that could lead to
>> spurious behavior - at least in principle (probably not in practice given
>> that if a wildcard appears as a toplevel type you never hit visitClassType).
>>
> I've updated:
> http://cr.openjdk.java.net/~shinyafox/kulla/8144903/webrev.04/
>
>
>> * I think you also use the wildcard lower bound, in case of a toplevel ?
>> super T. In that case, T is always better than Object.
>>
> I don't think so, because this printer is to determine a  suitable
> variable type which is assigned the expression of the "type " which is the
> argument of this printer.
> And a expression of "? super T" is not assignable to T:
> F<? super String> f = ...
> String s = f.get() // failed to compile
>
> Regards,
> shinyafox(Shinya Yoshida)
>
>
>
>>
>>
>> Maurizio
>>
>>
>> On 10/12/15 14:15, ShinyaYoshida wrote:
>>
>> Hi Maurizio and Robert,
>> Thank you for a lot of advice and comments!
>>
>> Now I agreed.
>> It is difficult( or impossible) to determine the completely "right" type
>> from bound.
>> And when I work hard around that, the work wouldn't bring benefit what is
>> worth the working to us.
>>
>> I'd like propose the fix based on webrev.02:
>> http://cr.openjdk.java.net/~shinyafox/kulla/8144903/webrev.03/
>>
>> In this patch:
>> 1. Fix 8144903(this issue)
>> 2. Use always wildcard instead of upper bound
>> 3. In visitWildcardType, if it is top-level type and it doesn't have
>> extends bound, return "Object"
>> 4. In TypePrinter, "Object" appears sometimes so I declare 'private
>> static final String OBJECT = "Object"' and use it instead of the literal.
>> 5. Add & modify some tests
>>
>> Could you review this?
>>
>> Best Regards,
>> shinyafox(Shinya Yoshida)
>>
>> 2015-12-10 19:32 GMT+09:00 Maurizio Cimadamore <
>> maurizio.cimadamore at oracle.com>:
>>
>>>
>>>
>>> On 10/12/15 03:07, Robert Field wrote:
>>>
>>>    public static Object $2;
>>>
>>> otherwise the generated code will break.
>>>
>>> What do you mean by this? How is using Object breaking the generated
>>> code? Seems to me you have just widened the type of a variable storing an
>>> expression - that ought to work; the only problem here is user
>>> expectations: if the user is expecting to pass this to a method accepting a
>>> CharSequence he/she will be disappointed. But how big of a problem is this?
>>> And, as I pointed out elsewhere, no general solution exists for this.
>>>
>>> Maurizio
>>>
>>
>>
>>
>
>