Comment on Unison | A friendly, statically-typed, functional programming language from the future · Unison programming language

Solumbran@lemmy.world ⁨11⁩ ⁨months⁩ ago

helloWorld : '{IO, Exception} () 
helloWorld _ = printLine "Hello World"

• EasternLettuce@lemm.ee ⁨11⁩ ⁨months⁩ ago

  [deleted]

  source

  • dneaves@lemmy.world ⁨11⁩ ⁨months⁩ ago

    Although, i would agree with it not necessarily being “friendly”, since its a drastically different syntax than many beginners would be used to, the brackets and parenthesis here are not what you think they are.

    Unison is a language in the style of Haskell, F#, Purescript, Elm, etc. So that first line is actually type annotations.

    In Haskell, this would just be main :: IO () , meaning a function named main with no arguments and produces what is essentally a potentially-unsafe IO action with a Void return (the empty parenthesis () ).

    Here in Unison they call the bracket part “abilities” or something. Its saying the same thing as Haskell, but being more explicit in saying it can raise an exception.

    source

    • abhibeckert@lemmy.world ⁨11⁩ ⁨months⁩ ago

      Yeah sorry - that’s just unnecessarily obtuse. Programming languages just don’t need to be that convoluted. Hello world should look something like this:

      print("Hello, World!")
      

      source

      • dneaves@lemmy.world ⁨11⁩ ⁨months⁩ ago

        Hello world should look something like this: print(“Hello, World”!)

        You don’t need the annotation line in Haskell-esque languages, most of the time. Without the annotation, this is Hello World in Haskell:

        main = print "Hello, World!"
        

        And when you need more complexity, it can still be far simpler than Unison (or Haskell)

        import qualified Data.List as List
        import Data.Function ((&))
        
        processNumbers numbers =
            let
                isEven n = mod n 2 == 0
            in
            numbers
                & List.filter isEven
                & List.map (^2)
        
        main =
            processNumbers [1, 2, 3, 4, 5, 6]
                & print
        

        source
  • hansl@lemmy.world ⁨11⁩ ⁨months⁩ ago

    It’s not parenthesis (in the PEMDAS sense), it’s the unit type and it’s normally expressed like that. If you’re not familiar with type systems, it’s the typing equivalent of void.

    source

    • EasternLettuce@lemm.ee ⁨11⁩ ⁨months⁩ ago

      [deleted]

      source

      • hansl@lemmy.world ⁨11⁩ ⁨months⁩ ago

        I’m not sure what you’re asking. Plenty of modern languages use the unit type; typescript, Rust, not sure you consider Haskell a modern language.

        From the look of it, this language seems to use it in a function signature declaration, which would make sense.

        source