[erlang-patches] EEP37: Funs with names

Henrik Nord <>
Thu Nov 15 15:22:33 CET 2012


I will add this patch to 'master-pu'.

Thank you for your contribution!


On 2012-11-14 17:42, Anthony Ramine wrote:
> This patch implements EEP37: Funs with names
>
> This adds optional names to fun expressions. A named fun expression
> is parsed as a tuple `{named_fun,Loc,Name,Clauses}` in erl_parse.
>
> If a fun expression has a name, it must be present and be the same in
> every of its clauses. The function name shadows the environment of the
> expression shadowing the environment and it is shadowed by the
> environment of the clauses' arguments. An unused function name triggers
> a warning unless it is prefixed by _, just as every variable.
> Variable _ is allowed as a function name.
>
> It is not an error to put a named function in a record field default
> value.
>
> When transforming to Core Erlang, the named fun Fun is changed into
> the following expression:
>
>      letrec 'Fun'/Arity =
>                 fun (Args) ->
>                         let <Fun> = 'Fun'/Arity
>                         in Case
>      in 'Fun'/Arity
>
> where Args is the list of arguments of 'Fun'/Arity and Case the
> Core Erlang expression corresponding to the clauses of Fun.
>
> This transformation allows us to entirely skip any k_var to k_local
> transformation in the fun's clauses bodies.
>
> 	https://github.com/nox/otp/compare/erlang:master...eep37
> 	https://github.com/nox/otp/compare/erlang:master...eep37.patch
>
> 	git fetch https://github.com/nox/otp eep37
>
> Regards,
>

-- 
/Henrik Nord Erlang/OTP



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