Project Lambda: Java Language Specification draft

[Neal Gafter]

I like the dot version, and it need not be specific to closures.  That
is, define the syntax

primary . ( expressions )

for SAM types to have the same meaning as

primary . invoke ( expressions )

where "invoke" is the name of the SAM's abstract method.  For example

Runnable r = ...;
r.(); // calls r.run()

-Neal

On Sat, Jan 23, 2010 at 3:00 PM, Stefan Schulz <schulz at the-loom.de> wrote:
> On 23.01.2010 17:43 Stephen Colebourne wrote:
>>>   #int(int) doubler = #(int x)(x + x);
>>>   assert doubler!(fortyTwo!()) == 84;
>>
>> I find the ! invocation pretty darn ugly I'm afraid. I can't help
>> reading "not". The symbol also blends into the brackets visually.
>
> I had the same association with "not".
>
>>   assert doubler.invoke(fortyTwo.invoke()) == 84;
>>
>> The simple approach is more verbose and explanatory, which is quite in
>> the style of Java.
>
> While I, as others, prefer the method-like invocation style, as it seems
> to be quite complex to solve issues with namespaces and such (at least
> in the time frame for JDK7), why not use a Java-like way to invoke a
> lambda? Maybe a shorter name than "invoke" would help:
>
>   assert doubler.with(fourtyTwo.with()) == 84;
>   assert doubler.on(fourtyTwo.on()) == 84;
>
> Or use ^ with a (maybe far-fetched) resemblance of a lambda character:
>
>   assert doubler.^(fourtyTwo.^()) == 84;
>   assert doubler^(fourtyTwo^()) == 84;
>
> (where the latter may be tricky to spot and distinct from exclusive or
> by a human reader).
>
> Cheers,
> Stefan
>
>