Removal of function types

Jesse Kuhnert jkuhnert at gmail.com
Wed Jul 7 17:58:01 PDT 2010


Well that clenches it, if reineir likes it there must be something
wrong. =p (just kidding, mostly..)

On Wednesday, July 7, 2010, Reinier Zwitserloot <reinier at zwitserloot.com> wrote:
> How timely, I was just about to post with the same thing.
>
> This latest round of lambda proposals obviously has my stamp of approval, as
> it's a virtual carbon copy of a proposal I put out on the lombok mailing
> list about a year ago, though I admit the inference of parameter types part
> of it is nifty and in retrospect perhaps an obvious next move once one has
> already accepted the burden of mandatory immediate conversion to an existing
> SAM type.
>
> The obvious solution to address situations such as the ParallelArrays.Ops
> explosion is to allow primitives in generics.
>
> This isn't _that_ difficult; I posted a proposal to this very list a while
> ago with a relatively simple scheme, that would nevertheless fit both
> primary requirements for PA.Ops:
>
>  - It allows you to eliminate the vast majority of PA.Ops's SAM types,
> leaving only the basic set (Reducer, Filter, etc, no more specializations
> such as LongReducer).
>
>  - Using a primitive PA with e.g. a Reducer<long> instead of LongReducer
> will achieve roughly the same performance, both CPU and memory wise.
>
> NB: And as I'm writing this, Brian chimes in that it would be way out of
> scope for JDK7. Well, specialization might be, but specialization isn't
> necessary. I'll reread my own proposal, update it where necessary, and
> repost it.
>
> --Reinier Zwitserloot
>
>
>
> On Thu, Jul 8, 2010 at 1:17 AM, Nathan Bryant
> <nathan.bryant at linkshare.com>wrote:
>
>> Perhaps there is an alternative middle ground, that would provide
>> function types but make them look like SAM's: variadic generics.
>>
>> Wink wink, nudge nudge.
>>
>>
>> -----Original Message-----
>> From: lambda-dev-bounces at openjdk.java.net
>> [mailto:lambda-dev-bounces at openjdk.java.net] On Behalf Of Doug Lea
>> Sent: Wednesday, July 07, 2010 7:06 PM
>> To: lambda-dev at openjdk.java.net
>> Subject: Re: Removal of function types
>>
>> On 07/07/10 13:18, Stephen Colebourne wrote:
>> > I suggest using this thread to comment on the removal of function
>> types :-)
>> >
>>
>> As one of the instigators-by-counter-example of function types,
>> I do wonder what the plan is for providing dozens if not
>> hundreds of SAM types for (parallel) aggregate operations.
>> As in my infamous workarounds at:
>> http://gee.cs.oswego.edu/dl/jsr166/dist/extra166ydocs/extra166y/Ops.html
>>
>> -Doug
>>
>>
>>
>>
>
>


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