Self function

[BCS]

Reply to Georg,

> bearophile wrote:
> 
>> Sometimes I rename recursive functions, or I duplicate and modify
>> 
> them, and they stop working because inside them there's one or more
> copy of their old name, so for example they recurse to their old name.
> 
>> So inside a function I'd like to have a standard name to call the
>> 
> function itself, useful for recursivity.
> 
>> (If you have two or more recursive functions that call each other
>> this
>> 
> idea can't be used, but I think such situations are uncommon enough to
> not deserve help from the language).
> 
>> I have just discussed this in the Python newsgroup too:
>> http://groups.google.com/group/comp.lang.python/browse_thread/thread/
>> d265da85d4b70eaf#
>> 
>> I use more recursivity in D than in Python, because Python has
>> troubles with it.
>> 
>> In future in D2 you may use:
>> 
>> int ANUGLYNAME(int n) {
>> if (n <= 1)
>> return 1;
>> else
>> mixin(__FUNCTION__ ~ "(n - 1) * n");
>> }
>> But you can't use __FUNCTION__ into a delegate/function
>> pointer/lambdabecause the name isn't available, and it's a bit ugly
>> syntax anyway...
>> 
>> This looks a bit better:
>> 
>> int ANUGLYNAME(int n) {
>> if (n <= 1)
>> return 1;
>> else
>> __self(n - 1) * n;
>> }
>> Other syntaxes are possible.
>> 
>> __self is a way to denote the pointer/delegate of the function
>> currently being run, so I think the compiler is always able to that,
>> for
>> delegate/ function pointers/ lambdas/ methods/ virtual methods/
>> opCalls too.
> Since you need this at compile time, then you don't need a pointer. A
> name would be enough.
> 
> If, as Denis pointed out, Andrei is going to provide that, and if it
> turns out to have a long name (like scope.function.name), then I hope
> it will be implemented so that you can alias that into something
> shorter, like "thisf" or "me".
> 


void main()
{
   int i = 0;
   auto dg = (int j)
   {
       i++;
       return j <= 1 ? 1 : self(j-1) + self(j-2); 

       // self can't be a name as the function dosn't have a name 
       // and it can't be a compile time const at the context is not known.
   };

   dg(5);
}