How do I do ADT in hy?

[glyh]

Here's a link of how do you do ADT in python.

I'm aware of we have match, but how would you implement a recursive tree with it?

[Kodiologist]

We've supported Python 3.11 for a while, so you can translate any of those examples to Hy in a literal fashion and the effect should be the same.

[glyh]

How do you translate this, then?

Shape = Point | Circle | Rectangle

EDIT:

Nvm I found out:

(setv Shape (| Point Circle Rectangle))

[glyh]

How do you annotate with @dataclass then?

[Kodiologist]

It sounds like you're figuring this out while you type. Try working on this yourself for a while and then come back if you're stuck.

[glyh]

I figured it out, something is not well-documented, but here's the final code for ADT example on SO:

(import dataclasses [dataclass])

(defclass [dataclass] Point []
  (annotate x float)
  (annotate y float))

(defclass [dataclass] Circle []
  (annotate x float)
  (annotate y float)
  (annotate r float))

(defclass [dataclass] Rectangle []
  (annotate x float)
  (annotate y float)
  (annotate w float)
  (annotate h float))

(setv Shape (| Point Circle Rectangle))

(defn print-shape [#^Shape shape]
  (match shape
    (Point x y)    (print f"Point {x} {y}")
    (Circle x y r) (print f"Circle {x} {y} {r}")
    (Rectangle x y w h) (print f"Circle {x} {y} {w} {h}")))

(print-shape (Point 1 2))
(print-shape (Circle 3 5 7))
(print-shape (Rectangle 11 13 17 19))
(print-shape 4)

I would say, though, it's kinda ugly. so I may write a macro for this.