> And there are certain classes of typed problems that are impossible without this feature, so it is highly useful!
Can you expand on this? I imagine it's expressions all the way down and type inference is still possible... so imagine it's a nice-to-have rather than must-have. Would like to understand more basically! On Tue, 15 Nov 2016 at 17:40, OvermindDL1 <overmind...@gmail.com> wrote: > On Tuesday, November 15, 2016 at 9:30:23 AM UTC-7, Max Goldstein wrote: > > My impression is that it's a Haskell extension that's very commonly used. > In the process of upgrading, I uncommented some signatures only for the > compiler to tell me that they are incorrect, so this feature has been > useful already. > > > Oh it is very useful! And there are certain classes of typed problems > that are impossible without this feature, so it is highly useful! > > An example of usage in OCaml anyway (since I have a shell of it up right > now): > ```ocaml > let f (x : 'x) = > let a (y : 'x) = () > in a > > let b = f 42 3 > ``` > That compiles right, changing b to this though: let b = f 42 3.14 > Causes this error: > ``` > Line 6, 14: Error: This expression has type float but an expression was > expected of type > int > ``` > Where this compiles fine (and may not only be entirely unexpected but > could hide major bugs later in the program!): > ```ocaml > let f x = > let a y = () > in a > > let b = f 42 3.14 > ``` > > -- > You received this message because you are subscribed to the Google Groups > "Elm Discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elm-discuss+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
