Jarrett Billingsley skrev:
On Wed, Apr 15, 2009 at 12:13 PM, Arild Boes <abo...@gmail.com> wrote:
Take a look at the 'this' of D2, it allows to create wrapper structs, so
you can just add methods to the built-in arrays.
Bye,
bearophile
Please elaborate on this. How does one do that?
With the new, delicious "alias this."
struct Array(T)
{
T[] blah;
alias blah this; // woo!
void print()
{
writefln(blah);
}
}
void main()
{
Array!(int) x;
// anything not defined in Array will instead be looked up in the
'alias this' member
x.length = 5;
x[2] = 3;
x.print();
}
Though actually I'm not sure why bearophile suggested this, since even
in D1, you can define 'extension' methods for arrays and AAs by simply
declaring a function that takes an array or AA as its first parameter.
It's syntactic sugar for a normal function call. By taking advantage
of templates and IFTI you can make these methods work for all kinds of
arrays.
void print(T)(T[] arr)
{
writefln(arr);
}
void main()
{
int[] x;
x.length = 5;
x[2] = 3;
x.print(); // same as print(x);
}
This will work in D1 or D2.
I see. Thank you very much for that answer.
Actually the f-call syntactic sugar seems like a good way to keep core
classes of any library very lean and mean, whilst maintaining the
ability to expand the module without re-compiling the original library!
(just import this guy, and the new functions will be available to you as
if declared in the original type).
