[erlang-questions] Fun type specifications

Loïc Hoguin essen@REDACTED
Mon Sep 17 13:20:12 CEST 2012


I came across this limitation a few times now. Assuming this is a 
limitation because I didn't find a solution.

For function specs you can do something like this:

-spec my_fun(Req) -> Req when Req::req().

You can't do this however.

-type my_fun_type() -> fun((Req) -> Req when Req::req()).

This is a bit annoying as this makes the typing of the funs a little 
less precise than I hoped.

Did I miss something and can you still do something like this? Or if 
not, can this be added eventually?


Loïc Hoguin
Erlang Cowboy
Nine Nines

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