Folks,
consider the following example: I want to keep a book in a variable and
use it as a function argument. But a variable containing a \book seems
to fail to match the ly:book? predicate in function argument checking.
How can this be explained?
As a workaround, I can use a no-parameter function that returns a book.
But I'd still like to understand what's happening here.
Lukas
\version "2.25.25"
myScore = \score { a4 }
bookVariable =
\book {
\myScore
}
bookFunction =
#(define-scheme-function () ()
#{
\book {
\myScore
}
#})
useBook =
#(define-void-function (book) (ly:book?)
(ly:message "I'm doing something with this book now."))
% \useBook \bookVariable % <<<<<<<< This fails. Why?
\useBook \bookFunction
