[erlang-questions] How to make this work

[Dmitry Kolesnikov]

Hello,

You can use built-in function
http://erldocs.com/17.0/stdlib/timer.html?i=0&search=timer:tc#tc/1

You can also check from OTP source the implementation of this function and compare it with your's
https://github.com/erlang/otp/blob/maint/lib/stdlib/src/timer.erl#L160

It gives you hints :-)

Best Regards, 
Dmitry

> On 12 Aug 2015, at 18:34, Roelof Wobben <r.wobben@REDACTED> wrote:
> 
> Hello,
> 
> Im trying this exercise from the programming erlang book.
> 
> Look up the definitions of erlang:now/0, erlang:date/0, and erlang:time/0. Write a
> function called my_time_func(F), which evaluates the fun F and times how
> long it takes.
> 
> So I did this :
> 
> -module(my_time).
> 
> -export( [time_spend/1] ).
> 
> time_spend(F) ->
>    Begintime = time:now(),
>    F(3),
>    Endtime = time:now(),
>    Endtime - Begintime.
> 
> 
> but then when I do this in erl :
> 
> 11> my_time:time_spend(fun x -> 2 * X end).
> * 1: syntax error before: '->'
> 11> my_time:time_spend(Double = fun x -> 2 * X end).
> * 1: syntax error before: '->'
> 
> how can I make this work ?
> 
> Roelof
> 
> 
> ---
> Dit e-mailbericht is gecontroleerd op virussen met Avast antivirussoftware.
> https://www.avast.com/antivirus
> 
> _______________________________________________
> erlang-questions mailing list
> erlang-questions@REDACTED
> http://erlang.org/mailman/listinfo/erlang-questions