Local functions

[Rémi Forax]

Le 10/02/2010 14:52, Mark Mahieu a écrit :
> On 10 Feb 2010, at 13:09, Rémi Forax wrote:
>    
>> There is a simple solution, if you want to write recursive function,
>> create a static method
>> and reference it as a lambda:
>>
>> class A {
>>    static int factorial(int x) {
>>      return (x<= 1) ? 1 : x*factorial.(x-1);
>>    }
>>
>>       public static void main(String[] args) {
>>           #int(int) lambda = A#factorial;
>>       }
>> }
>>
>>      
> I don't think that approach is quite so simple if your recursive function needs to use locals in the method which 'creates' it (eg. it references 'args' in 'main', in your example).
>
> Regards,
>
> Mark
>    

In that case, the anonymous class syntax is your friend.

Or if lambdas are translated to method handles, you can write:

class A {
   static int foo(String[] args, int x) {
     return (x<= 1) ? args.length : x*foo.(x-1);
   }

   public static void main(String[] args) {
     #int(int) lambda = A#foo.bindTo(args);
   }
}

cheers,
Rémi