-\version "2.15.17"
+\version "2.19.22"
\header{
texidoc= "Test backup of predicate-based optional music function arguments.
Unit expressions like @code{3\cm} can't be parsed as optional
-arguments since they would require lookahead after @code{3}. However,
-if @code{3} gets rejected as an optional argument based on evaluating
-its predicate, it should still be able to participate as part of a unit
-expression in a following mandatory argument."
+arguments in one go since they would require lookahead after @code{3}.
+The predicate is checked after @code{3}, and if it is suitable,
+Lilypond commits to parsing as a unit number, and checks the result
+again. For the predicate @code{integer?} and @code{3\cm}, you would
+actually get a syntax error (since the combination is no longer an
+integer) rather than Lilypond trying to see @code{3\cm} as two
+separate arguments."
+
}
\layout { ragged-right = ##t }
-test=#(define-void-function (parser location expect . rest)
- (list? (string? "def1") (integer? "def2") (number-pair? "def3") integer?)
+test=#(define-void-function (expect . rest)
+ (list? (string? "def1") (integer? "def2") (fraction? "def3") integer?)
(if (not (equal? expect rest))
- (ly:parser-error parser
- (format #f "Expected ~a, got ~a.\n" expect rest)
- location)))
+ (ly:parser-error
+ (format #f "Expected ~s, got ~s.\n" expect rest)
+ (*location*))))
twice=2
-\test #'("a" 3 (3 . 4) 8) "a" 3 3/4 4\twice
-\test #'("a" 3 "def3" 8) "a" 3 4\twice
-\test #'("a" 4 "def3" 2) "a" 4\twice
+\test #'("x" 3 (3 . 4) 8) x 3 3/4 4\twice
+\test #'("x" 3 "def3" 8) x 3 4\twice
+\test #'("x" 8 "def3" 10) x 4\twice 5\twice
\test #'("def1" "def2" "def3" 8) 4\twice