(and (pair? x)
(ly:moment? (car x)) (ly:moment? (cdr x))))
+(define-public (boolean-or-number? x)
+ (or (boolean? x) (number? x)))
+
(define-public (boolean-or-symbol? x)
(or (boolean? x) (symbol? x)))
+(define-public (key? x)
+ (or (symbol? x) (index? x)))
+
+(define-public (key-list? x)
+ (and (list? x) (every key? x)))
+
+(define-public (key-list-or-music? x)
+ (if (list? x)
+ (every key? x)
+ (ly:music? x)))
+
+(define-public (key-list-or-symbol? x)
+ (if (list? x)
+ (every key? x)
+ (symbol? x)))
+
(define-public (symbol-list? x)
(and (list? x) (every symbol? x)))