6 ms·

I mean adding setters/getters to existing data types. It's solved in any language in which mutable data structures don't require a Rube Goldberg machine like l

• the_af 7y ago
  Oh. Ruby. In any case, adding getters/setters doesn't imply extensibility and doesn't apply to FP languages (or rather: in FP languages you can add more functions). Getters/setters are often an anti-pattern anyway. Maybe you have a better example? In any case it's very easy to "extend" types in Haskell, it just looks different to what you'd do in Ruby. As for expressive power, are you familiar with the "expression problem"? [0] There's almost always a trade-off your language is making. I don't understand what you mean by law of non-contradiction in this context. [0] the expression problem: https://en.m.wikipedia.org/wiki/Expression_problem https://en.m.wikipedia.org/wiki/Expression_problem
  • ukj 7y ago
    Getters/setters may be seen as anti-patterns in the functional paradigm. They are seen as pattern in the imperative paradigm. Of course I am making trade-offs, but so are you. It's just another word for making choices. What I mean is literally being able to evaluate P ∧ ¬P as True, as an empirical test for a language's expressivity. You can't do that in Haskell - it won't let you. The language is in control, not you. In my problem-space not being in control is an anti-pattern.
    • the_af 7y ago
      I meant getters/setters are an antipattern in OOP languages. In FP there are no getters or setters, so the question is meaningless. Ruby is not more expressive than Haskell. In fact, I'm pretty sure it's less expressive, because it cannot say everything Haskell can, but Haskell can say everything Ruby can. You say you understand everything is a trade-off but then you make claims about lack of expressivity ;) Do you know the expression problem? Still don't understand your non-contradiction example.
      • ukj 7y ago
        >Still don't understand your non-contradiction example. >Haskell can say everything Ruby can Go ahead and say P ∧ ¬P ⇔ True in Haskell. Here is me saying it in Ruby: https://repl.it/repls/AccurateJauntyDimension https://repl.it/repls/AccurateJauntyDimension
        • the_af 7y ago
          Neat. How did you do that? (Seems like something a language ought to forbid, anyway). edit: ok, from what I've deciphered from your Ruby code, it's nothing special. You've declared a global boolean and every invocation of function "p" flips the value, so it's only a parlor trick and nothing to do with the expressivity of the language. Any language with side-effects and mutable globals will achieve this trick in the same manner. It's a trick because your first "p" and your second "p" aren't the same "p", so there's no real violation of the "law of non-contradiction". What about the rest of my comment? The expression problem? That getters/setters are an anti-pattern in OOP languages (just ask Alan Kay...)?
          • ukj 7y ago
            > Seems like something a language ought to forbid, anyway > What about the rest of my comment? The expression problem? Navigating around the expression problem is precisely what I am demonstrating. A language ought not [1] decide for me what I am allowed to express or not. I have a healthy disregard for linguistic purism [2]. Expressive power is the ability to say whatever I want to, whenever I want to. That is precisely what a para-consistent logic buys me - expressivity [3]. This is counter-intuitive to most people who have been taught to value consistency above all else (mathematicians, logicians). Non-contradiction is an axiom, not a law - it's a false authority. A man-made deity. > it's nothing special I didn't claim it's anything special - I merely claimed that I can say it. I did say it. If "Haskell can say everything Ruby can" then go ahead and say it in Haskell. I am not saying it's impossible - but I a curious how you might navigate the Turing tarpit [4]. >It's a trick because your first "p" and your second "p" aren't the same "p" First p and second p? You mean p@time(1) and p@time(2)? Are 'you' not the same 'you' as the 'you' from 1 second ago, despite the ongoing changes in your body? Ironically, that is the disconnect between pure functions and reality. Side-effects are the norm, not the exception. >That getters/setters are an anti-pattern in OOP languages (just ask Alan Kay...) That's an appeal to authority. Alan Kay doesn't get to make decisions for me. He gets to voice his opinion - I get to evaluate the pros and cons. The choice is always mine. Like I said - In my problem-space lack of choice/control is an anti-pattern. Humans get the final say - not algorithms. [1] https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem [2] https://en.wikipedia.org/wiki/Linguistic_prescription https://en.wikipedia.org/wiki/Linguistic_prescription [3] https://en.wikipedia.org/wiki/Paraconsistent_logic#Paraconsistent_logics_and_classical_logic https://en.wikipedia.org/wiki/Paraconsistent_logic#Paraconsi... [4] https://en.wikipedia.org/wiki/Turing_tarpit https://en.wikipedia.org/wiki/Turing_tarpit