Re: Issue 3720: Built-in templates for SATB vocal scores (issue 41990043)

[dak]

On 2014/01/12 08:05:30, Devon Schudy wrote:
> David Kastrup wrote:
> > At any rate, I'm not really happy with the macro usage at top level
> > here: I think it would be better if the basic assembly was rather
done
> > by music or Scheme functions

> I'm not really happy with it either, because users have no hope of
> modifying it or learning from it. The macro-generated version is much
> shorter, but that's not worth the inability to copy and modify. I
> rewrote it using functions, but that's not much easier for users, and
> is almost as long as the original version with no attempt to factor
> out the repetition.

> The reason for the macros is so the definedness of variables can be
> checked at macroexpand time, to avoid compiling references to
> undefined names — that works in Guile 1.8 but not in Guile 2, and it's
> bad style anyway.

Checking for the definedness of variables at macroexpand time?  Ugh.

How about
define-variables =
#(define-void-function (parser location syms) (symbol-list?)
   (for-each
      (lambda (sym)
        (if (null? (ly:parser-lookup parser sym))
            (ly:parser-define parser sym *unspecified*)))))

If you write \name for a variable with value *unspecified*, it simply
disappears in the lexer.


https://codereview.appspot.com/41990043/