I want to imitate golang's interface in D, to study D's
template. I wrote
some code: https://gist.github.com/3123593
Now we can write code like golang:
--
interface IFoo {
void foo(int a, string b, float c);
}
struct Foo {
void foo(int a, string b, float c) {
writeln("Foo.foo: ", a, ", ", b, ", ", c);
}
}
struct FooFoo {
void foo(int a, string b, float c) {
writeln("FooFoo.foo: ", a, ", ", b, ", ", c);
}
}
GoInterface!(IFoo) f = new Foo;
f.foo(3, "abc", 2.2);
f = new FooFoo;
f.foo(5, "def", 7.7);
--
It is also very naive, does not support some features, like
out/ref
parameters, free functions *[1]* and so on. The biggest
problem is downcast
not supported. In golang, we can write code like*[2]*:
--
var p IWriter = NewB(10)
p2, ok := p.(IReadWriter)
--
Seems [p.(IReadWriter)] dynamically build a virtual table
*[3]*，because the
type of "p" is IWriter, it is *smaller* than IReadWriter, the
cast
operation must search methods and build vtbl at run time.
In D, GoInterface(T).opAssign!(V)(V v) can build a rich
runtime information
to *V* if we need. But if *V* is interface or base class, the
type
information not complete. So, seems like I need runtime
reflection? and how
can I do this in D? I did not find any useful information in
the TypeInfo*.
------
[1] free functions support, e.g.
--
interface IFoo {
void foo(int a, string b, float c);
}
void foo(int self, int a, string b, float c) {
writefln("...");
}
GoInterface!(int) p = 1;
p.foo(4, "ccc", 6.6);
--
In theory no problem.
