adt_matching.py

from enum import Enum
class ADTValue:
	__slots__=('adt','value')
	def __init__(self, adt, value):
		self.adt=adt
		self.value=value
	def __repr__(self):
		return f'{self.adt!r} of {self.value!r}'
class ADT(Enum):
	def __call__(self, other):
		if not isinstance(other, ADTValue):
			print(f"fill values {self}, {other}")
			return ADTValue(self, other)
		
		if other.adt == self:
			return other.value
		return False

class Result(ADT):
	Ok = ('T',)
	Err = ('E',)
	Quasi = {'r', 'err'}

r = Result.Quasi([1, "hi"])

if v := Result.Ok(r):
	print("Ok.T=",v)
elif e := Result.Err(r):
	print("Err.e=",e)
elif q := Result.Quasi(r):
	[qr, qerr]=q
	print(f"Quasi.r={qr}, Quasi.err={qerr}")