Re: Problem with scaled durations

[Trevor Daniels]

David Kastrup wrote Friday, January 04, 2013 9:15 AM

> "Trevor Daniels" <address@hidden> writes:
> 
>> David Kastrup wrote Friday, January 04, 2013 8:21 AM
>>
>>> Oscar Dub <address@hidden> writes:
>>>>
>>>> From a user perspective, I thought it might be nice for the compiler
>>>> to send out some kind of error or warning message. Currently there's
>>>> no sign of anything wrong except the final output. Is this valid
>>>> enough an issue to be worth a quick bug report?
>>> 
>>> Overflow in C++ Rational arithmetic would take effort to reliably and
>>> would complicate the code base considerably.  At some point of time, the
>>> Rational class will likely get replaced with Scheme rationals (which
>>> have "arbitrary precision") and the problem will go away.
>>
>> Until then we ought to document this as a "Known issue" in NR 1.2.1
>> under Scaling durations.
>>
>> Copying to Bug list so bug squad can raise a Doc issue if they agree.
> 
> I disagree.  LilyPond uses "Rational" in a number of places, like for
> alterations/accidentals/tunings, time management in general, and... uh.
> 
[snip long list]
>
> Uh, possibly something in relation to beaming.  That would seem to be
> about it.  But at any rate, there are oodles of places in LilyPond where
> you can trigger silent overflow in non-Guile types.  Totally not
> restricted to duration scales.

True, but which of these have a simple documented user command
like *m/n which could provoke the problem, and how many have a
demonstrated example of a user encountering it?  Those criteria are the
important ones, together with the knowledge that the issue is unlikely to
be fixed, in deciding what should be documented as a Known issue.

Trevor