Re: A question on "##t"

[Kieren MacMillan]

Hi Damian (et al.),

> actually, this confuses me too

There may be a better (and, likely, more accurate) explanation than  
the one I'm about to give... but this works for me, so I hope it  
helps you.  =)

> if the # puts lilypond into scheme mode, does that mean that
> the equals-sign in #'merge-differently-headed = ##t  is not scheme?

Yes! You are coding a key-value setting, i.e.,

    #'property-to-set = [??]

The question (and confusion) comes in how to present [??]. If  
property-to-set requires [??] to be a Scheme expression -- which most  
(if not all) Lilypond properties do -- then you need to tell the  
parser that [??] should be interpreted as a Scheme expression:

    #'property-to-set = #[??]

Now, the question remains whether [??] a "simple" number as  
represented in Scheme, e.g.,

    #'property-to-set = #1

or a Scheme pair, e.g.,

    #'property-to-set = #'(1 . 2)

or a "reserved Scheme value", e.g.

    #'property-to-set = ##t

and so on.

If property-to-set requires [??] to *not* be a Scheme expression, then

    #'property-to-set = 1\mm

(or whatever) would be sufficient.

> if it is, then why not #'merge-differently-headed = #t?

Because then the Scheme value of [??] would be t, which doesn't mean  
anything in Scheme.  ;-)

I realise this response has a roughly equal chance of making you MORE  
confused as it does LESS... but I hope it's the latter!

Best wishes,
Kieren.