@typeof Proposal

[eladb]

As I was reviewing the introduction of @type and std.Type, I was wondering what would be the best way to support the use case of exploring the type of an object.

Here's a quick sketch of my thoughts:

class Bar {}
class Foo extends Bar {}

let bar = new Bar();
let foo = new Foo();

assert(@typeof(bar) == @type(Bar));
assert(@typeof(foo).asClass().extends(@type(Bar));

struct Bang {
  x: str;
  y: str;
}

struct Bing {
  x: str;
}

assert(@typeof(Bang) == @type(Bang));
assert(@typeof(Bang).asStruct().assingableTo(@typeof(@Bing))); // << structural typing

Basically the idea is that @typeof(x) will return an std.Type that's the same as the one returned by @type(<the type of x>) :-).