I have created two interesting D entries for this Rosettacode Task, is someone willing to create a Reddit entry for this? They show very different kinds of code in D.

http://rosettacode.org/wiki/Look-and-say_sequence#D

Bye,
bearophile

On Friday, 15 November 2013 at 01:09:53 UTC, bearophile wrote:
> I have created two interesting D entries for this Rosettacode Task, is someone willing to create a Reddit entry for this? They show very different kinds of code in D.
>
> http://rosettacode.org/wiki/Look-and-say_sequence#D
>
> Bye,
> bearophile

>> Using the LDC2 compiler with n=70 the run-time is about 3.74 seconds.

Timings for short functional version vs fast would be nice.

--rt

On 11/15/2013 02:09 AM, bearophile wrote:
> I have created two interesting D entries for this Rosettacode Task

len.uninitializedArray ? Isn't this too much UFCS?

Rob T:

> Timings for short functional version vs fast would be nice.

OK. On the other hand regarding speed the fast version is in another world. So the speed comparison will become a little silly.

--------------

Martin Nowak:

> len.uninitializedArray ? Isn't this too much UFCS?

I think it's just enough of UFCS.

Bye,
bearophile

> OK. On the other hand regarding speed the fast version is in another world. So the speed comparison will become a little silly.

The first program doesn't even compile with ldc2 v.2.063.2, and the two programs are quite different in scope...

Bye,
bearophile

Rob T:

> Timings for short functional version vs fast would be nice.

Below the two I have added a note to compare the run-times.

Bye,
bearophile

On Friday, 15 November 2013 at 01:09:53 UTC, bearophile wrote:
> I have created two interesting D entries for this Rosettacode Task, is someone willing to create a Reddit entry for this? They show very different kinds of code in D.
>
> http://rosettacode.org/wiki/Look-and-say_sequence#D
>
> Bye,
> bearophile

I didn't look that closely at the imperative code, but it seems to be quite a bit longer than most of the other imperative examples. Is this because it's super-optimized?

Meta:

> I didn't look that closely at the imperative code, but it seems to be quite a bit longer than most of the other imperative examples. Is this because it's super-optimized?

Yes, it's longer because it's optimized.

Bye,
bearophile

On Friday, 15 November 2013 at 01:09:53 UTC, bearophile wrote:
> I have created two interesting D entries for this Rosettacode Task, is someone willing to create a Reddit entry for this? They show very different kinds of code in D.
>
> http://rosettacode.org/wiki/Look-and-say_sequence#D

The fast version is nearly functional, too. Since memory management is not considered a side effect there is only the printfs. If the printfs are wrapped into "debug", the function is pure.

On 2013-11-15 02:09, bearophile wrote:
> I have created two interesting D entries for this Rosettacode Task, is
> someone willing to create a Reddit entry for this? They show very
> different kinds of code in D.
>
> http://rosettacode.org/wiki/Look-and-say_sequence#D

What does this show, that ranges is slow in D?

-- 
/Jacob Carlborg