Re: spacer rest *

[David Wright]

On Tue 01 May 2018 at 09:15:31 (+0200), David Kastrup wrote:
> David Wright <address@hidden> writes:
> 
> > On Tue 01 May 2018 at 00:15:24 (+0200), David Kastrup wrote:
> >> David Wright <address@hidden> writes:
> >> 
> >> > AFAICT the important exception that was introduced with naked
> >> > durations was that c 4 notates a single note whereas c4 4 notates two.
> >> 
> >> There was no "exception" introduced.  c 4 always indicated a single note
> >> and c4 4 previously was invalid input.
> >
> > There's no guarantee that a new user, or a user who has only set eyes
> > on notation like c4, will make the correct interpretation of, say,
> > c 4 4 4 when they first encounter it. Without looking it up, there's
> > no way of knowing whether LP would treat it as three notes or four.
> 
> Without looking anything up, you cannot know the interpretation of anything.

LOL. I'm sorry, I have this vision of a child checking through the
meanings of the dozen words they learned this week.

>  At any rate, I objected to an "exception" being "introduced"
> since LilyPond continued behaving absolutely the same for any previously
> valid input.

Well, it helps to look at the sentence's context which you removed
when you originally quoted it, viz:

    > The disadvantage is that introduce one exception and the exception has to
    > be specified in the manual. But when you start learning something new, you
    > concentrate on essentials things not on details/exceptions. Don't know if
    > other people work the same but this is how does it works for me.

    AFAICT the important exception that was introduced with naked
    durations was that c 4 notates a single note whereas c4 4 notates two.
    BTW although this point is explained in LM (page 23), I don't think it
    has made it into NR yet.

So the context was "start learning something new": the learner's
experience rather than the power user's.

With this change in LP semantics, LM introduced this warning:

"… but remember that a bare pitch followed by a space and a bare duration will 
be interpreted
 as a single note. In other words, c4 a 8 8 would be interpreted as c4 a8 a8, 
not as c4 a4 a8 a8.
 Write instead c4 a4 8 8 ."

People learning LP 2.19.81 have to learn that every " 8 " is not the
same. If the " 8 " follows a naked pitch, it is treated differently.
People who learned with LP 2.18.2 did not have to learn that. I'm
perfectly happy if you prefer not to see that a new learner might view
it as an exception. After all, you're immersed in the language.

> Spaces never ever were relevant.  And we did not even
> start putting spaces into the documentation where they hadn't been
> before except in very particular circumstances (like drum notation using
> always the same drum).
> 
> > So if a new user thinks that a naked duration always specifies a note
> > they're likely to see the first duration in c 4 4 4 as an exception.
> 
> The first duration in c 4 4 4 is not a naked duration.  It's not the
> space which makes it "naked" but the lack of pitch to attach to.

Where does it actually say that?

> Let me quote the documentation on this:
> 
>        Isolated durations – durations without a pitch – that occur within a
>     music sequence will take their pitch from the preceding note or chord.
> 
>          \relative {
>            \time 8/1
>            c'' \longa \breve 1 2
>            4 8 16 32 64 128 128
>          }
> 
>          [music image]
> 
>        Isolated pitches – pitches without a duration – that occur within a
>     music sequence will take their duration from the preceding note or
>     chord.  If there is no preceding duration, then default for the note is
>     always ‘4’, a quarter note.
> 
> Nowhere does this talk about spaces.

… which of course it should, if only to say that such whitespace
 is optional and not preferred. That would make it is clearer that
    c4 d e f
    8 8 8 8 8 8 8 8
defines only 11 notes. The NR should be a reference for definitions
like this, should it not.

Similarly AFAICT, nowhere is it defined that you can write naked
durations in lyrics, but that
    \skip 4 Hm!4 hm!4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
won't work for Papageno because it only generates blanks.

Cheers,
David.