RFR 8037106: Optimize Arrays.asList(...).forEach

[Sergey Bylokhov]

On 3/17/14 7:41 PM, Paul Sandoz wrote:
> On Mar 15, 2014, at 12:17 AM, Ulf Zibis <Ulf.Zibis at CoSoCo.de> wrote:
>
>> Am 14.03.2014 17:10, schrieb Paul Sandoz:
>>>> I'm willing to believe for-loop over array is as efficient as fortran-style loop
>>>>
>>>> +            for (E e : a) {
>>>> +                action.accept(e);
>>>> +            }
>>>>
>>> Yeah, i previously went through a whole bunch of code replacing such fortran-style loops with 'foreach' style based on automated code analysis.
>> But wouldn't this help a little more? :
>> +            final E[] a = this.a;
>> +            for (E e : a) {
>> +                action.accept(e);
>> +            }
>>
> Thanks, i changed it to that.
? Why this line is needed:

final E[] a = this.a;

Since according to specification foreach over array should be 
transformed to:
JLS 14.14.2:
*T[] #a = Expression; *
L1: L2: ... Lm:
for (int #i = 0; #i < #a.length; #i++) {
     VariableModifiersopt TargetType Identifier = #a[#i];
     Statement
}

So your code will be transformed to:

+            final E[] a = this.a;
+            E[] #a = a;
+            for (E e : #a) {
+                action.accept(e);
+            }
Or I miss something?

>> I more like the given style with less spaces:
>> 3854                 for (int i=0; i<a.length; i++)
>> It better visualizes the 3 parts of the for statement.
>>
> Subjectively that irritates my eyes :-) non-subjectively it is inconsistently applied.
>
> Paul.


-- 
Best regards, Sergey.