Re: Optional arguments for scheme functions

[Lukas-Fabian Moser]

Am 26.04.20 um 10:30 schrieb Thomas Morley:
> > However, when I swap integer? for positive? (to reflect the fact that only a 
> > positive integer should be acceptable) it breaks, telling me the argument at 
> > position 1 is of the wrong type (it’s music, not a positive number).  Why 
> > doesn’t scheme’s handling of optional arguments work when using the positive? 
> > predicate?
> I've no clue why positive? fails here.
> Though, for integers >= 0 we have the index? predicate, which works in
> your function.

Well, positive? does not seem to like being called with anything else 
than a number:

(positive? "I'm a string")

fails as well.

I'm not sure as to why that is the case; but anyway, this shows that the 
problem does not come from LilyPond.

Best
Lukas