• pineapple (4/4) Oct 23 2015 Is it possible to have default method implementations in
• Alex Parrill (20/24) Oct 23 2015 Use template mixins: http://dlang.org/template-mixin.html
• pineapple (5/7) Oct 23 2015 Awesome, thanks!
• Adam D. Ruppe (8/12) Oct 23 2015 Use a mixin template together with your interface. Here's an
• Steven Schveighoffer (7/10) Oct 23 2015 If the idea is to have an implementation that *doesn't* get overridden,

pineapple <meapineapple gmail.com> writes:

Is it possible to have default method implementations in 
interfaces à la Java in D? Or some equivalent that allows 
multiple inheritance without a bunch of identical copypasted 
method bodies?

Alex Parrill <initrd.gz gmail.com> writes:

On Friday, 23 October 2015 at 14:58:43 UTC, pineapple wrote:
 Is it possible to have default method implementations in 
 interfaces à la Java in D? Or some equivalent that allows 
 multiple inheritance without a bunch of identical copypasted 
 method bodies?

Use template mixins: http://dlang.org/template-mixin.html

interface MyInterface {
     void foo();
     int bar();
}

mixin template MyInterfaceDefaultImpl() {
     void foo() {
         // put code here
     }
     int bar() {
         // put code here
     }
}

class MyClass : MyInterface {
     mixin MyInterfaceDefaultImpl!(); // Similar to inserting the 
body of `MyInterfaceDefaultImpl` at this point.
     mixin MyOtherInterfaceDefaultImpl!(); // Can put any amount 
of them here.
}

pineapple <meapineapple gmail.com> writes:

On Friday, 23 October 2015 at 15:07:05 UTC, Alex Parrill wrote:
 Use template mixins: http://dlang.org/template-mixin.html

On Friday, 23 October 2015 at 15:08:30 UTC, Adam D. Ruppe wrote:
 Use a mixin template together with your interface.

Awesome, thanks!

No way, though, to unite declaration and implementation? Feels a 
little too much like endless header files to me.

Adam D. Ruppe <destructionator gmail.com> writes:

On Friday, 23 October 2015 at 14:58:43 UTC, pineapple wrote:
 Is it possible to have default method implementations in 
 interfaces à la Java in D? Or some equivalent that allows 
 multiple inheritance without a bunch of identical copypasted 
 method bodies?

Use a mixin template together with your interface. Here's an 
example from my book:

http://arsdnet.net/dcode/book/chapter_06/09/multiple_inheritance.d

https://www.packtpub.com/application-development/d-cookbook

Notice that there's default implementations for each interface, 
you mix them in to get it all and can override individual names 
in the class too.

Steven Schveighoffer <schveiguy yahoo.com> writes:

On 10/23/15 10:58 AM, pineapple wrote:
 Is it possible to have default method implementations in interfaces à la
 Java in D? Or some equivalent that allows multiple inheritance without a
 bunch of identical copypasted method bodies?

If the idea is to have an implementation that *doesn't* get overridden, 
you can have final methods in an interface.

I know it's not what you asked for, but sometimes people may ask for 
something they know not realizing that something else may satisfy their 
needs :)

-Steve