While working with the v1.12.0 rc0 release, I wrote the following typespec:
@spec my_fun(1..10//2) :: boolean() which resulted in the following error: == Compilation error in file lib/foobar.ex == ** (CompileError) lib/foobar.ex:6: type ..///3 undefined (no such type in Foobar) My confusion stemmed from my belief that ranges in typespecs were interpreted by Elixir and expanded at compile time (e.g. 1..10 to 1|2|3|4|5|...) since the syntax (first..last) matches the Elixir range syntax and Erlang has no native ranges. Of course, this was wrong because while Erlang doesn't have ranges, *Dialyzer* does. While I can't think of the last time I wanted the contract of my function to be "only accepts odd integers between 1 and 100", it also seems like a curious omission. From the perspective of someone with good knowledge of Elixir but limited knowledge of Erlang and Dialyzer, I had originally believed that this was some kind of mistake or oversight. There also might be a use-case in providing additional information to Dialyzer, such as: @spec odd?(1..10//2) :: true @spec odd?(2..10//2) :: false Would it be worth taking a type such as 1..10//2 and compiling it to 1|3|5|7|9 for Dialyzer? -- 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 elixir-lang-core+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/d9415490-4285-48fe-a863-4d778ccc962an%40googlegroups.com.
