On Tuesday, 16 June 2020 at 11:31:14 UTC, Atila Neves wrote:
On Tuesday, 16 June 2020 at 11:24:05 UTC, jmh530 wrote:
On Tuesday, 16 June 2020 at 09:15:10 UTC, Atila Neves wrote:
[snip]
In the more longer-term, is the goal of the project to
implement a Typescript / Go interfaces like structural type
system in user space?
Yes. Other than allowing multiple interfaces, I think it's
already implemented.
I'm not familiar with what Typescript does, but doesn't Go
allow interfaces to be implemented by free-standing functions?
So does tardy.
Sorry, I had not realized that. I took Go's interface example and
converted it to D. Would this work with tardy?
```
import tardy;
interface IGeometry
{
double area() @safe pure const;
double perim() @safe pure const;
}
alias Geometry = Polymorphic!IGeometry;
struct Rect {
double width, height;
}
struct Circle {
double radius;
}
double area(Rect r) {
return r.width * r.height
}
double perim(Rect r) {
return 2 * r.width + 2 * r.height
}
double area(Circle c) {
import std.math: PI;
return PI * c.radius * c.radius
}
double perim(Circle c) {
import std.math: PI;
return 2 * PI * c.radius
}
void measure(IGeometry g) {
import std.stdio: writeln;
writeln(g);
writeln(g.area);
writeln(g.perim);
}
void main() {
auto r = Rect(3.0, 4.0);
auto c = Circle(5.0);
r.Geometry.measure;
c.Geometry.measure;
}
```
That is a little bit more similar to open methods. This
requires the type inherit from the interface and implement
member functions.
There is no inheritance anywhere, otherwise that'd defeat the
point of the library in the first place. I used interfaces
because they exist and intuively make sense, and support
classes because why not. Otherwise it could be just structs and
other values with candidate UFCS functions.
Sorry, that was me being hasty. I was just concerned about the
member functions part of it, which you said above is not a
concern.
