I have notes about `=` too, I just focus on `<-` more because it seems a bigger difference in usage to me. ^.^
On Thursday, August 25, 2016 at 6:34:39 PM UTC-6, Ben Wilson wrote: > > "/me really dislikes operators that do different things in different areas" > > But that's exactly what happy makes the `=` operator do, and of all the > operators in use `=` is by far the most used! `<-` effectively means "this > is going to be bound according to the logic of the monad we're in". It > isn't in common use outside of `for`, and `with` merely generalizes on that. > > On Thursday, August 25, 2016 at 1:22:15 PM UTC-4, José Valim wrote: >> >> >> Testing, indeed it is not valid there. :-) >>> >>> I wonder if it would be worth supporting such a case, I could report it >>> in any case, done. :-) >>> >> >> My point is that changing the AST is a slippery slope. I will likely >> always find an example that fails because of precedence and mangling. >> >> Hmm, soft-matching operator, makes sense. Any chance on updating the >>> docs at >>> http://elixir-lang.org/docs/stable/elixir/Kernel.SpecialForms.html#for/1 >>> where it states "Enumerable generators are defined using <-:" to >>> something of that form, maybe like "`<-` matches on each given element and >>> skips non-matches", although that still does not match how `with` does it. >>> Hmm, it seems that `for` and `with` are using an identical operator in >>> incompatible ways. >>> >> >> Improving the docs is a great idea. And again, the skipping or not is >> defined by the enclosing with or for. All <- does is to check if something >> matches. All you need to know is that the left side is a pattern. >> >> >>> Hmm, having `when` be directly adjacent to `=` in precedence, what side >>> effects would that have? I do not think that `=` is allowed adjacent to a >>> `when` that I can think of in function heads (which are the only other case >>> where `when` is used that comes to immediate mind) so no issue there. >>> >> >> As mentioned in the previous email, it is related to the precedence of = >> and when on the left side of ->. Play with the grammar and let us know if >> you can make both "x when y = z" and "x = y when z -> w" work. Maybe if >> both operators have the same precedence and are left associative? >> >> >> >> -- >> >> >> *José Valim* >> www.plataformatec.com.br >> Skype: jv.ptec >> Founder and Director of R&D >> >> -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/5ae1060d-fb71-4e87-9039-7812e08240cb%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
