On 09/16/2016 01:10 AM, Urs Liska wrote:
Doesn't a conversion to
#`(id . ,(existing-function))
suffice? Otherwise just follow Carl's suggestion.
Hi Urs, Almost, but you have to add a lambda wrapper to pass along the
implicit grob argument, and then there are other more challenging
complications if the user has supplied a lambda expression or a variable
that may be a string or a procedure. So most of the possibilities are
non-trivial to impossible to handle well. See below.
Cheers,
-Paul
\version "2.19.42"
#(define procA (lambda (grob) (display "a ") "myid"))
#(define (procB grob) (display "b ") "myid")
procC = #(lambda (grob) (display "c ") "myid")
procE = "myid"
{
% ORIGINALS
\override NoteHead.id = #procA
c1
\override NoteHead.id = #procB
c1
\override NoteHead.id = \procC
c1
\override NoteHead.id = #(lambda (grob) (display "d ") "myid")
c1
\override NoteHead.id = \procE
c1
% RE-WRITES
% these are fine (as long as the variable is a procedure):
\override NoteHead.id = #(lambda (grob) `(id . ,(procA grob)))
c1
\override NoteHead.id = #(lambda (grob) `(id . ,(procB grob)))
c1
\override NoteHead.id = #(lambda (grob) `(id . ,(procC grob)))
c1
% to regex a lambda expression, I think you'd have to count matching
% parens to arbitrary depth. Not sure that is possible with regex...
\override NoteHead.id =
#(lambda (grob) `(id . ,((lambda (grob) (display "d ") "myid") grob)))
c1
% is \procE a string or a procedure? No way to tell in convert-ly
% and calling a string as if it were a procedure doesn't work
% \override NoteHead.id = #(lambda (grob `(id . ,(procE grob))))
c1
}
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