;;;; This file is part of LilyPond, the GNU music typesetter.
;;;;
;;;; Copyright (C) 1998--2020 Jan Nieuwenhuizen <janneke@gnu.org>
;;;;                 Han-Wen Nienhuys <hanwen@xs4all.nl>
;;;;
;;;; LilyPond is free software: you can redistribute it and/or modify
;;;; it under the terms of the GNU General Public License as published by
;;;; the Free Software Foundation, either version 3 of the License, or
;;;; (at your option) any later version.
;;;;
;;;; LilyPond is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;;; GNU General Public License for more details.
;;;;
;;;; You should have received a copy of the GNU General Public License
;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.

;;; Note: this file can't be used without LilyPond executable


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; type predicates.
(define-public (number-pair? x)
  (and (pair? x)
       (number? (car x)) (number? (cdr x))))

(define-public (number-pair-list? x)
  (and (list? x)
       (every number-pair? x)))

(define-public (fraction? x)
  (and (pair? x)
       (index? (car x)) (index? (cdr x))))

(define-public (rational-or-procedure? x)
  (or
   (and (rational? x) (exact? x))
   (procedure? x)))

(define-public (number-or-grob? x)
  (or (ly:grob? x) (number? x)))

(define-public (grob-list? x)
  (list? 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))))

(define-public (boolean-or-number? x)
  (or (boolean? x) (number? x)))

(define-public (boolean-or-symbol? x)
  (or (boolean? x) (symbol? x)))

(define-public (integer-or-markup? x)
  (or (integer? x) (markup? 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)))

(define-public (symbol-list-or-music? x)
  (if (list? x)
      (every symbol? x)
      (ly:music? x)))

(define-public (string-or-symbol? x)
  (or (string? x) (symbol? x)))

(define-public (number-or-string? x)
  (or (number? x) (string? x)))

(define-public (string-or-pair? x)
  (or (string? x) (pair? x)))

(define-public (string-or-music? x)
  (or (string? x) (ly:music? x)))

(define-public (number-or-pair? x)
  (or (number? x) (pair? x)))

(define-public (cheap-list? x)
  (or (pair? x) (null? x)))

(define-public (symbol-list-or-symbol? x)
  (if (list? x)
      (every symbol? x)
      (symbol? x)))

(define-public (scale? x)
  (or (and (rational? x) (exact? x) (not (negative? x)))
      (fraction? x)
      (and (ly:moment? x) (scale? (ly:moment-main x)))))

(define-public (scale->factor x)
  ;; assumes valid input
  (cond ((pair? x) (/ (car x) (cdr x)))
        ((rational? x) x)
        ((ly:moment? x) (ly:moment-main x))
        (else #f)))

(define-public (scheme? x) #t)


(define-public (void? x)
  (unspecified? x))

;; moved list to end of lily.scm: then all type-predicates are
;; defined.
(define type-p-name-alist '())

(define (match-predicate obj alist)
  (if (null? alist)
      "Unknown type"
      (if (apply (caar alist) obj)
          (cdar alist)
          (match-predicate obj (cdr alist)))))

(define-public (object-type obj)
  (match-predicate obj type-p-name-alist))

(define-public (object-type-name obj)
  (type-name (match-predicate obj type-p-name-alist)))

(define-public (type-name predicate)
  (let ((entry (assoc predicate type-p-name-alist)))
    (if (pair? entry) (cdr entry)
        (string-trim-right
         (symbol->string (procedure-name predicate))
         #\?))))
