OMN processing function creation example

Posted March 19, 20178 yr

Hi,

Here is a short example of OMN deconstruction/reconstruction technique useful when you want to do functions for working directly with omn.

;; Example of function application based on binary-list.              
(flatten (do-section '(0 1 0) '(chord-interval-add '(4)  x) (mclist '(c4 d4 e4))))

;;; Function example to search for '1/4 length and process the corresponding
;;; pitch for add Major 3rd interval when '1/4 is found.
;;; It is also a good example of deconstruction/reconstruction of OMN 
;;; inside a function

(defun add-3rd-quarter (omn)
  (let ((plist (disassemble-omn omn)))
    (setf (getf plist :pitch)
          (flatten 
           (do-section
            (binary-invert (gen-binary-remove '1/4 (getf plist :length)))
            '(chord-interval-add '(4) x)
            (mclist (getf plist :pitch)))))
    (apply 'make-omn plist)))

(add-3rd-quarter '(e c4 p d4 q e4 f stacc e f4 p a4 q g4 f stacc))
=> (e c4 p d4 q e4gs4 f stacc e f4 p a4 q g4b4 f stacc)

SB.

March 19, 20178 yr

an other solution... same result...

greetings

andré

;;; by using SINGLE-EVENTS ->  my preferred tool

(defun alt-add-3rd-quarter (omn-list)
  (loop for i in (single-events omn-list)
    when (equal (first i) 'q)
    append (omn-replace :pitch (chord-interval-add '(4) (list (second i))) i)
    else append i))
  

(alt-add-3rd-quarter '(e c4 p d4 q e4 f stacc e f4 p a4 q g4 f stacc))
=> (e c4 p e d4 p q e4gs4 f stacc e f4 p e a4 p q g4b4 f stacc)