Re: Scheme: Syntax for storing a variable in an alist

[David Kastrup]

Jean Abou Samra <jean@abou-samra.fr> writes:

> Le 18/10/2020 à 22:10, Matthew Fong a écrit :
>
>> Hello Aaron and Jean,
>>
>> Many thanks for pointing out the finer points of syntax of Scheme
>> vs. LilyPond.
>>
>> I appreciate the Scheme quoting reference, and the syntactic
>> sugar. Still so much more to learn here!
>
> You live and learn; I learnt about the synctactic sugar just today.

Lots of syntactic sugar came into being in the last few versions.  This
particular bit has been around a while.

commit 59d1c295b6c6ebe9410362cc365349bd458b0bcf
Author: Joe Neeman <joeneeman@gmail.com>
Date:   Tue Dec 22 21:44:56 2009 -0800

    Add nested properties setting to \paper blocks.

Though this would have needed writing

var #'prop #'prep = ...

instead of

var.prop.prep = ...

at that time.  The availability of the latter syntax was probably an
unintended side effect of

commit 864ce06c432a62191773b0d59401348c9b51568c
Author: David Kastrup <dak@gnu.org>
Date:   Mon Oct 8 17:52:36 2012 +0200

    Allow property and grob paths to be constructed from strings
    
    This allows use of either
    \override Accidental color = #red
    or
    \override Accidental.color = #red
    (in addition to existing forms), both for context modifications or for
    property overrides in music, the latter with optional leading context
    spec defaulting to Bottom. .  The same holds for reverts.

which would peg this as 2.17.6 (quite later than I would have thought).
I think that this assignment-level syntax only got formalised later on.

-- 
David Kastrup