Re: Ada202X : Adding functors

[Martin <martin@thedowies.com>]

On Thursday, November 15, 2012 12:31:42 PM UTC, Georg Bauhaus wrote:
> On 15.11.12 08:12, Martin wrote:
> 
> > Yup...I think I listed lambdas in another post...possibly even my 'No 1'! No chance of me using them in my C++ work, our compilers aren't up to C++11.
> 
> >
> 
> 
> 
> If lambda-expressions should help with not naming small
> 
> expressions that don't deserve a name (that'll be fun!),
> 
> and if lambda-expressions need not be passed upwards,
> 
> then maybe more along the lines of if-expressions, and
> 
> expression functions,
> 
> 
> 
> with Ada.Containers.Vectors;
> 
> 
> 
> procedure Foo is
> 
>     
> 
>     package Nats is new Ada.Containers.Vectors
> 
>       (Index_Type => Positive,
> 
>        Element_Type => Natural);
> 
> 
> 
>     V : Nats.Vector;
> 
>     Sum : Natural := 0;
> 
> 
> 
> begin  -- not Ada
> 
> 
> 
>     V.Iterate (Process => (with (Position : Cursor) do
> 
>                              Sum := Sum + Element (Position)));
> 
> 
> 
>     declare
> 
>        Copy2 : Nats.Vector;
> 
>     begin
> 
>        for E of V loop
> 
>           Copy2.Append
> 
>             (New_Item =>
> 
>                (with (X : Natural => E) return Natural is
> 
>                   2 * X));
> 
>        end loop;
> 
>     end;
> 
> 
> 
> end Foo;

+1