Feature request: Register new operators

[Tiago-Lira]

Flipper's latest version supports these kind of operators:

• __gt Greater than
• __gte Greater than or equal to
• __lt Less than
• __lte Less than or equal to
• __ne Not equals
• __in Set membership
• __not_in Set non-membership

However, a complex program may require extra or custom operators. The only way to add new operators are opening a pull-request or doing a hack:

from typing import Iterable

from flipper.conditions.operators.interface import AbstractOperator
from flipper.conditions.operators import Operator


class OverlapOperator(AbstractOperator):
    SYMBOL = "overlap"

    def compare(
        self,
        expected: Iterable,
        actual: Iterable,
    ) -> bool:
        return bool(set(expected) - set(actual)) is False


Operator.OPERATOR_MAP[OverlapOperator.SYMBOL] = OverlapOperator

I'll open a pull-request adding OverlapOperator. But I'd love to hear thoughts about being able to add custom operators for specific projects.

[adambom]

I don't think we'll add OverlapOperator to the main repo. I don't totally understand the use case and I don't think it will be used all that often.

My preference would be to add a register method to the operator factory: flipper.conditions.operators.Operator. Then you could have a public interface for registering any new operators you want. I'll review that PR if you want to put it together.

class Operator:
    @classmethod
    def register(cls, operator: AbstractOperator):
        cls.OPERATOR_MAP[operator.SYMBOL] = operator