Make alias parameter optional?

[Ali Çehreli]

On 02/26/2012 03:45 AM, Jacob Carlborg wrote:
 > On 2012-02-26 11:03, Ali Çehreli wrote:
 >> On 02/25/2012 05:04 PM, Robert Rouse wrote:
 >> > On Saturday, 25 February 2012 at 23:10:51 UTC, Ary Manzana wrote:
 >> >> On 2/25/12 7:31 PM, Robert Rouse wrote:
 >>
 >> ...
 >>
 >> >>> This means that D can simulate Ruby blocks more than I thought.
 >> That's
 >> >>> pretty awesome. I'm loving D more every day.
 >> >>
 >> >> How's that like a Ruby block?
 >> >
 >> > The D code simulates the following Ruby if you were to make bar print
 >> > "something" with writeln.
 >> >
 >> > def foo(a, b, &block)
 >> > puts "a is #{a}")
 >> > b.call
 >> > yield
 >> > end
 >> >
 >> > f = lambda { puts "good bye" }
 >> >
 >> > foo(1, f) { puts "something" }
 >> >
 >> >
 >> > That's what I'm talking about.
 >> >
 >>
 >> I don't know Ruby but from what I've read so far about Ruby blocks,
 >> their D equivalents may also be D ranges.
 >>
 >> Ali
 >
 > A Ruby block is basically like a delegate in D and has nothing to do
 > with ranges.
 >
 > Ruby:
 >
 > def foo (&block)
 > block.call
 > end
 >
 > foo do
 > p "asd"
 > end
 >
 > D:
 >
 > void foo (void delegate () block)
 > {
 > block();
 > }
 >
 > void main ()
 > {
 > foo({
 > writeln("asd");
 > });
 >
 > foo(() => writeln("asd")); // new lambda syntax
 > }
 >
 > Both examples print "asd". If you want to have a more Ruby looking
 > syntax in D you do some operator overload abuse:
 >
 > struct Block
 > {
 > void delegate (void delegate ()) impl;
 >
 > void opIn (void delegate () block)
 > {
 > impl(block);
 > }
 > }
 >
 > Block foo ()
 > {
 > return Block((x) => x());
 > }
 >
 > void main ()
 > {
 > foo in {
 > writeln("asd");
 > };
 > }
 >

I see, thanks. The reason I thought about ranges is that the yield 
statement in the Ruby code above reminded me of Python's generators, and 
that D's ranges can also take the role of generators.

Ali