chocolatedonut
Will, or should, Elixir 1.20 types warn when a struct is in a list and a struct’s key is mistyped? Only the uncommented Enum.reject line produces a warning (and already pre-1.20, at least in 1.18). Is there a plan that the shorthand (Enum.reject(& &1.c == 1)) will also warn?
defmodule A do
defstruct [:b]
end
def test do
[%A{b: 1}]
|> Enum.reject(fn %A{} = a -> a.c == 1 end) # warns
# |> Enum.reject(fn a -> a.c == 1 end) # doesn't warn
# |> Enum.reject(& &1.c == 1) # doesn't warn
end
Apologies for a potentially ignorant question, as I haven’t been following the compiler development closely.
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josevalim
It will eventually warn on shorthand. The code looks simple but getting this particular example to warn via the type system requires parametric types (and a lot of work behind the scenes!).