5 ms·

I appreciate the beauty of the pointfree style but whenever I tried to use it I found that I couldn't read my own code the next day. It seems that my brain is j

I appreciate the beauty of the pointfree style but whenever I tried to use it I found that I couldn't read my own code the next day. It seems that my brain is just hard wired to expect a list of parameters in a function definition. EDIT: That is, all these years at school I was taught to write f(x) = x^2, not f = (^2).

eru 15y ago
They should have told you write f = (x -> x^2) or so.
- JadeNB 15y ago
  I think it's better pedagogically just to acknowledge that, in common mathematical discourse, "the squaring function" doesn't have any symbolic name. Perhaps it's more illustrative to think of, for example, `f(x) = ln(x)` (the value of a function) versus `f = ln` (the function itself); and a good (college) mathematics teacher will make this distinction.
- perfunctory 15y ago
  They could also tell me to write (= f (-> (x) (^ x 2))). Then we would all be using lisp and laughing and those few developers who would using that weird infix notation.
  - eru 15y ago
    While I like S-Expressions for computers, even in that small example the parenthesis are a bit excessive. Keep in mind that mathematics is mostly written by hand on a black board.
    - JadeNB 15y ago
      Ah, so it's postfix you want? fxx2^1+→= :-)
      - eru 15y ago
        On a blackboard I want to (ab)use that I have a nice and flat surface, and don't have to be restricted to linear strings of characters.
jerf 15y ago
I don't think a Haskeller should try to use point-free code. It's just that if you're refactoring your code and you get it down to the point that you've got thing x = th . in . g x you might as well finish the job and take the x out. What's left should make sense to you if you follow this process and just let it happen. But I feel no shame when I can't go pointfree, especially when pointfree requires crazy hacks to simulate a simple pattern match.
- JadeNB 15y ago
  Sorry, but, aside from the obviously unimportant use of `in` (a reserved word), this gives a different type from what I think you meant: x :: a g :: a -> b -> c in :: c -> d th :: d -> e thing :: a -> b -> e and naïve eta-conversion will give you something that isn't well typed. Probably you meant thing x = th . in . g $ x
  - jerf 15y ago
    Yes, thanks.

eru 15y ago

They should have told you write f = (x -> x^2) or so.

JadeNB 15y ago
I think it's better pedagogically just to acknowledge that, in common mathematical discourse, "the squaring function" doesn't have any symbolic name. Perhaps it's more illustrative to think of, for example, `f(x) = ln(x)` (the value of a function) versus `f = ln` (the function itself); and a good (college) mathematics teacher will make this distinction.
perfunctory 15y ago
They could also tell me to write (= f (-> (x) (^ x 2))). Then we would all be using lisp and laughing and those few developers who would using that weird infix notation.
- eru 15y ago
  While I like S-Expressions for computers, even in that small example the parenthesis are a bit excessive. Keep in mind that mathematics is mostly written by hand on a black board.
  - JadeNB 15y ago
    Ah, so it's postfix you want? fxx2^1+→= :-)
    - eru 15y ago
      On a blackboard I want to (ab)use that I have a nice and flat surface, and don't have to be restricted to linear strings of characters.

jerf 15y ago

I don't think a Haskeller should try to use point-free code. It's just that if you're refactoring your code and you get it down to the point that you've got thing x = th . in . g x you might as well finish the job and take the x out. What's left should make sense to you if you follow this process and just let it happen. But I feel no shame when I can't go pointfree, especially when pointfree requires crazy hacks to simulate a simple pattern match.

JadeNB 15y ago
Sorry, but, aside from the obviously unimportant use of `in` (a reserved word), this gives a different type from what I think you meant: x :: a g :: a -> b -> c in :: c -> d th :: d -> e thing :: a -> b -> e and naïve eta-conversion will give you something that isn't well typed. Probably you meant thing x = th . in . g $ x
- jerf 15y ago
  Yes, thanks.