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0 pointslmm8y ago0 comments

The point is that if you forget to write one of the ReactSpecialization methods nothing detects it. Perhaps more importantly, if you add a new type of Animal there's nothing to tell you you need to write a bunch of new ReactSpecializations.

0 comments

lacampbell8y ago

Aha! There's the crux of an argument. It's a valid point actually, that ties into the expression problem.

As an OO apologist I do feel compelled to point out that

    type Animal = Cat | Dog | Mouse

    let react = function (a, b)
    | Cat, Dog -> ...

    ...

    | x, y -> $"{x} is not interested in {y}."

Would suffer from the exact same issue though.

lmmOP8y ago

Only if you deliberately add the catch-all case. If you don't and just handle all the cases explicitly, many languages will give you a warning or error when you add a new unhandled variant.

lacampbell8y ago

Yeah, it's a valid point.

j / k navigate · click thread line to collapse

0 pointslmm8y ago0 comments

0 comments

lacampbell8y ago

Aha! There's the crux of an argument. It's a valid point actually, that ties into the expression problem.

As an OO apologist I do feel compelled to point out that

    type Animal = Cat | Dog | Mouse

    let react = function (a, b)
    | Cat, Dog -> ...

    ...

    | x, y -> $"{x} is not interested in {y}."

Would suffer from the exact same issue though.

lmmOP8y ago

Only if you deliberately add the catch-all case. If you don't and just handle all the cases explicitly, many languages will give you a warning or error when you add a new unhandled variant.

lacampbell8y ago

Yeah, it's a valid point.

j / k navigate · click thread line to collapse