Re: Can you get typeof(this) in a mixin template - trying to mimic a Kotlin feature here.
On Tuesday, 28 August 2018 at 20:58:23 UTC, Alex wrote:
Isn't the problem, that inside a template a declaration is
expected, and not a foreach?
Boh, you're right. I guess I misunderstood mixin templates. Found
a way with a normap function though :p
void mapSelf(alias self, alias aa)() { ... }
this(map) {
mapSelf!(this, map);
}
https://run.dlang.io/is/EhDpOM
Re: Can you get typeof(this) in a mixin template - trying to mimic a Kotlin feature here.
On Tuesday, 28 August 2018 at 20:39:16 UTC, aliak wrote:
Hi,
I'm trying to do something similar to what Kotlin allows with
assigning to member variables from a map. The syntax is very
readable and looks like:
class User(val map: Map) {
val name: String by map
val age: Int by map
}
So I'm trying to do something similar in D:
mixin template MapMembers(alias aa) {
foreach (name; typeof(this).tupleof) {
// if name is in aa, then mixin(m = aa[" ~ m ~ "]) ... ish
}
}
struct User {
this(Variant[string] aa) {
mixin MapMembers!aa;
}
}
Seems I can't do typeof(this) inside the mixin.
One workaround is to explicitly pass the type "User" to the
template mixin, but it feels like this is something that should
work and I'm just unfamiliar with template mixins and their
usage.
Cheers,
- Ali
[0]
https://kotlinlang.org/docs/reference/delegated-properties.html#storing-properties-in-a-map
Isn't the problem, that inside a template a declaration is
expected, and not a foreach?
This works as expected:
´´´
import std.experimental.all;
void main()
{
writeln("Edit source/app.d to start your project.");
}
mixin template MapMembers(alias aa) {
typeof(this) var;
/*
foreach (name; typeof(this).tupleof) {
// if name is in aa, then mixin(m = aa[" ~ m ~ "]) ... ish
}
*/
}
struct User {
this(Variant[string] aa) {
mixin MapMembers!aa;
}
}
//mixin MapMembers!(Variant[string].init);
´´´
Can you get typeof(this) in a mixin template - trying to mimic a Kotlin feature here.
Hi,
I'm trying to do something similar to what Kotlin allows with
assigning to member variables from a map. The syntax is very
readable and looks like:
class User(val map: Map) {
val name: String by map
val age: Int by map
}
So I'm trying to do something similar in D:
mixin template MapMembers(alias aa) {
foreach (name; typeof(this).tupleof) {
// if name is in aa, then mixin(m = aa[" ~ m ~ "]) ... ish
}
}
struct User {
this(Variant[string] aa) {
mixin MapMembers!aa;
}
}
Seems I can't do typeof(this) inside the mixin.
One workaround is to explicitly pass the type "User" to the
template mixin, but it feels like this is something that should
work and I'm just unfamiliar with template mixins and their usage.
Cheers,
- Ali
[0]
https://kotlinlang.org/docs/reference/delegated-properties.html#storing-properties-in-a-map
