[erlang-bugs] fun_info(F, env) always empty?

Ulf Wiger <>
Sun Feb 19 11:18:21 CET 2012


Ah, of course. Didn't consider that it could be the effect of constant propagation. :)

Thanks.

BR,
Ulf W

On 19 Feb 2012, at 08:46, Björn Gustavsson wrote:

> On Fri, Feb 17, 2012 at 6:23 PM, Ulf Wiger <> wrote:
>> 
>> According to the documentation, fun_info(F, env) will always be empty for external funs. It *doesn't* say, of course, that it will *not* be empty for other types of fun, but it would seem a reasonable conclusion.
>> 
>> What gives?
> 
> You will see a non-empty empty environment if
> the fun has a non-empty environment.
> 
> In your case, you will see it if you use the 'no_copt'
> option to disable constant propagation (among other
> optimizations) or if you rewrite f/0 like this:
> 
> f() ->
>    f(1, 2).
> 
> f(X, Y) ->
>    fun() ->
> 	    X-Y
>    end.
> 
> /Björn
> 
> -- 
> Björn Gustavsson, Erlang/OTP, Ericsson AB



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