memoize

[Jonathan M Davis]

On Monday 03 January 2011 21:27:22 Andrei Alexandrescu wrote:
> On 1/3/11 11:01 PM, Guilherme Vieira wrote:
> > On Tue, Jan 4, 2011 at 2:50 AM, Nick Sabalausky <a at a.a> wrote:
> >     "Andrei Alexandrescu" <SeeWebsiteForEmail at erdani.org
> >     <mailto:SeeWebsiteForEmail at erdani.org>> wrote in message
> >     news:ifu70u$2dvs$1 at digitalmars.com...
> >     
> >      >I just added a higher-order function memoize to std.functional
> >      >which I
> >     
> >      >think is pretty cool. See the docs here:
> >     http://d-programming-language.org/cutting-edge/phobos/std_functional.
> >     html#memoize
> >     
> >      > I'm also thinking of adding that cutting-edge directory as a
> >     
> >     place for
> >     
> >      > storing documentation for commits that are in flux but not
> >      > officially released yet.
> >      > 
> >      > 
> >      > Andrei
> >     
> >     Neat! This is a great example of why D kicks so much ass :)
> > 
> > Uh, yes. It looks like the kind of thing I would do, show to others and
> > hear they say "Meh.. Whatever". I'm really exponentially developing a
> > liking to the D community, even though I didn't event get to code
> > anything serious yet.
> > 
> > This simply rocks. Keep it up, Andrei!
> > 
> > --
> > Atenciosamente / Sincerely,
> > Guilherme ("n2liquid") Vieira
> 
> Glad you folks like it. There's a little story behind this. I first read
> Dominus' book chapter years ago, around the time I'd decided to write
> TDPL. Back then I was thinking - it would just be so cool to be able to
> define generic memoization in D. I tried my hand at an implementation.
> But D had no tuples, no aliasing for functions, no good variadics, and
> even if you could find a way to pack parameters, associative arrays had
> plenty of related issues.
> 
> I'd given up on that and forgot most about it, until today. It was nice
> to reckon that getting it done took about a dozen lines and about as
> many minutes. We really have come a very long way.
> 
> Nevertheless, I found two issues: one, ParameterTypeTuple doesn't work
> for overloaded functions, and associative arrays don't work for ubyte[4]
> keys... still a ways to go.

Well, it's definitely cool.

- Jonathan M Davis