(define-public (fraction? x)
(and (pair? x)
- (integer? (car x)) (integer? (cdr x))
- (>= (car x) 0) (>= (cdr x) 0)))
+ (index? (car x)) (index? (cdr x))))
(define-public (number-or-grob? x)
(or (ly:grob? x) (number? x)))
(define-public (number-list? x)
(and (list? x) (every number? x)))
+(define-public (index? x)
+ (and (integer? x) (>= x 0)))
+
(define-public (moment-pair? x)
(and (pair? x)
(ly:moment? (car x)) (ly:moment? (cdr x))))