[m-users.] How do you go about logging?

Left Right olegsivokon at gmail.com
Mon Apr 7 02:54:32 AEST 2014


Oh, alright, thanks for all your help!
Seems like I've to do more reading :)

Best,

Oleg

On Sun, Apr 6, 2014 at 2:00 PM, Julien Fischer <jfischer at opturion.com> wrote:
>
> Hi,
>
> On Sun, 6 Apr 2014, Left Right wrote:
>
>> Thanks for reply!
>>
>> Would you be so kind as to point me to the docs where I should read on
>> what "trailed" means?
>
>
> It's described in the ``Trailing'' section of the reference manual.
> <http://www.mercurylang.org/information/doc-latest/mercury_ref/Trailing.html#Trailing>
>
> Trailing is not relevant here other than the fact mutables are trailed
> by default.
>
>
>> Other then that: do I understand it correctly that "ground" in this
>> context means something roughly equivalent to C++ constexpr? I.e.
>> something that doesn't require calling functions to be computed.
>
>
> No, ground here just means that a term has a definite value and doesn't
> contain any variables.  In the example being discussed that means that
> Factor must have a definite value by the time the call to io.write/3
> is made -- that differs from C++ style constexprs where the value would
> be required to be known at compile time.
>
>
>> If so, is there a way for the programmer to promise to the compiler that
>> this is the kind of variable it is? And if this is not the way it
>> works, then where could I read about this mechanism?
>
>
> The mode system is discussed in chapter 4 of the reference manual.
>
>
>> I've so far only red the book.pdf downloadable from the documentation
>> section of the site, but I see that it's far from being enough for
>> even simple stuff :)
>
>
> This is covered in chapter 3 of that book.  I think your experience
> here may have been a bit misleading, probably due to the fact that
> trace goals and mutables are _not_ "simple stuff".  The compiler could
> also be a bit clearer about exactly what's wrong here.  (Incidentally,
> if you remove the trace goal from the predicate, then the compiler is
> quite clear about what's wrong.)
>
> Cheers,
> Julien.



More information about the users mailing list