4 ms·

You can like lambdas without wanting to go fully functional... just like you can like objects without wanting to go fully object-oriented.

gaius 16y ago
Those are called structs ;-)
- bruceboughton 16y ago
  Not everyone accepts that the object systems in Java and .NET are fully object-oriented.
  - loup-vaillant 16y ago
    Considering that no definition of "object-oriented" is accepted by everyone, I'm not sure your criticism is valid. My suggestion: drop the term "object-oriented" altogether, and refer to more specific features.
    - bruceboughton 16y ago
      Which brings me back round to my initial assertion: >> You can like lambdas without wanting to go fully functional
      - loup-vaillant 16y ago
        Well, F# and Ocaml aren't purely functional… so you're right.
loup-vaillant 16y ago
Well, I'm not sure. First, assignments are evil[1], which means you should avoid setters. Second, inheritance is evil, for similar reasons (thick interface). Third, every time I saw mixins or class polymorphism, lambdas or sum types, would have been simpler, respectively. Once you like lambdas, functional programming becomes more attractive than a black hole. [1]: http://www.loup-vaillant.fr/articles/assignment http://www.loup-vaillant.fr/articles/assignment
- barrkel 16y ago
  Sum types are not as dynamically extensible at runtime, or by third party libraries, as class polymorphism.
  - loup-vaillant 16y ago
    For the particular cases I saw, runtime extensibility never mattered. (Do you have one where it does?) And extending a third party sum type is not very hard: data LibType = Zero | One Int | Two Int Int data MyType = ZeroOneTwo LibType | Three Int Int Int (It of course implies that you use MyType instead of LibType in your code.) Finally, if you really want to extend a sum type, no work around allowed, you might want to look at Ocaml's variant types.
    - vetinari 16y ago
      The keywords were "extensible dynamically at runtime", not just "extensible, period". Runtime extensibility matters at systems that you cannot shut down, where have to upgrade live systems, for example. If you are doing just "run it once again, no big deal" application, then it does not matter, you are right.
    - barrkel 16y ago
      The code using LibType is code you don't control; you can't change it to use MyType instead. Indeed, you don't even have the source code to it. That's also why the extensibility happens at runtime.
      - loup-vaillant 16y ago
        So What? Just do what you would have done in Java without inheritance: aggregate. For each function that matters, you can write a new one that handle the extra case: new_function ZeroOneTwo x = old_function x new_function Three a b c = -- handling new case
        16y ago
jamii 16y ago
Note that both F# and Ocaml have object systems and have excellent support for imperative style programming. http://caml.inria.fr/pub/docs/u3-ocaml/ocaml-objects.html#advanced http://caml.inria.fr/pub/docs/u3-ocaml/ocaml-objects.html#ad...
- jules 16y ago
  Note that OO programming in F# requires a lot of type annotations (even more than in C#, you need to explicitly upcast).

gaius 16y ago

Those are called structs ;-)

bruceboughton 16y ago
Not everyone accepts that the object systems in Java and .NET are fully object-oriented.
- loup-vaillant 16y ago
  Considering that no definition of "object-oriented" is accepted by everyone, I'm not sure your criticism is valid. My suggestion: drop the term "object-oriented" altogether, and refer to more specific features.
  - bruceboughton 16y ago
    Which brings me back round to my initial assertion: >> You can like lambdas without wanting to go fully functional
    - loup-vaillant 16y ago
      Well, F# and Ocaml aren't purely functional… so you're right.

loup-vaillant 16y ago

Well, I'm not sure. First, assignments are evil[1], which means you should avoid setters. Second, inheritance is evil, for similar reasons (thick interface). Third, every time I saw mixins or class polymorphism, lambdas or sum types, would have been simpler, respectively. Once you like lambdas, functional programming becomes more attractive than a black hole. [1]: http://www.loup-vaillant.fr/articles/assignment http://www.loup-vaillant.fr/articles/assignment

barrkel 16y ago
Sum types are not as dynamically extensible at runtime, or by third party libraries, as class polymorphism.
- loup-vaillant 16y ago
  For the particular cases I saw, runtime extensibility never mattered. (Do you have one where it does?) And extending a third party sum type is not very hard: data LibType = Zero | One Int | Two Int Int data MyType = ZeroOneTwo LibType | Three Int Int Int (It of course implies that you use MyType instead of LibType in your code.) Finally, if you really want to extend a sum type, no work around allowed, you might want to look at Ocaml's variant types.
  - vetinari 16y ago
    The keywords were "extensible dynamically at runtime", not just "extensible, period". Runtime extensibility matters at systems that you cannot shut down, where have to upgrade live systems, for example. If you are doing just "run it once again, no big deal" application, then it does not matter, you are right.
  - barrkel 16y ago
    The code using LibType is code you don't control; you can't change it to use MyType instead. Indeed, you don't even have the source code to it. That's also why the extensibility happens at runtime.
    - loup-vaillant 16y ago
      So What? Just do what you would have done in Java without inheritance: aggregate. For each function that matters, you can write a new one that handle the extra case: new_function ZeroOneTwo x = old_function x new_function Three a b c = -- handling new case
      - 16y ago

jamii 16y ago

Note that both F# and Ocaml have object systems and have excellent support for imperative style programming. http://caml.inria.fr/pub/docs/u3-ocaml/ocaml-objects.html#advanced http://caml.inria.fr/pub/docs/u3-ocaml/ocaml-objects.html#ad...

jules 16y ago
Note that OO programming in F# requires a lot of type annotations (even more than in C#, you need to explicitly upcast).