My first email to Walter, ever

[Artur Skawina]

On 07/07/13 14:27, Peter Alexander wrote:
> template allSatisfy(alias F, T...)
> {
>     static if (T.length == 0)
>     {
>         enum allSatisfy = true;
>     }
>     else static if (T.length == 1)
>     {
>         enum allSatisfy = F!(T[0]);
>     }
>     else
>     {
>         enum allSatisfy =
>             allSatisfy!(F, T[ 0  .. $/2]) &&
>             allSatisfy!(F, T[$/2 ..  $ ]);
>     }
> }
> 
> Still looks like half-assed functional programming to me.
> 
> Where's the iteration? Why can't I write this?
> 
> template allSatisfy(alias F, T...) {
>     foreach(t; T)
>         if (!F!(t))
>             return false;
>     return true;
> }
> 
> (Those are rhetorical questions btw, before anyone links me to a D tutorial).

template allSatisfy(alias F, T...) {
   enum allSatisfy = {
      foreach (E; T)
         if (!F!E)
            return false;
      return true;
   }();
}

// And no, it isn't perfect. But not /that/ much is missing.
// It's the more complex cases that would benefit from more meta features.

artur