Split utils, scales, and fretboard.

3 files changed, 122 insertions, 99 deletions

diff --git a/scales/fretboard.scm b/scales/fretboard.scm
new file mode 100644
index 0000000..97bb1f5
--- /dev/null
+++ b/scales/fretboard.scm
@@ -0,0 +1,83 @@
+(define-module (scales fretboard)
+  #:use-module (ice-9 match)
+  #:use-module (ice-9 format)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-9)
+  #:use-module (srfi srfi-26)
+  #:use-module (scales utils)
+  #:export (tuning-guitar
+            tuning-grand-stick-matched-reciprocal-6+6
+
+            string-frets
+            fretboard
+
+            print-fretboard
+            print-stick))
+
+
+;;; Tunings
+
+(define tuning-guitar
+  '(e a d g b e))
+
+(define tuning-grand-stick-matched-reciprocal-6+6
+  '((b e a d g c) (b e a d g c)))
+
+
+(define-record-type <fret>
+  (make-fret position note)
+  fret?
+  (position fret-position)
+  (note     fret-note))
+
+
+
+(define* (string-frets root scale-notes
+                       #:optional (frets 7) (fret-offset 0))
+  "Represent an instrument string as a list of FRETS frets.  Each fret
+contains a <FRET> object holding its position (starting from
+FRET-OFFSET) as well as the scale note matching one of the SCALE-NOTES
+at this position or #f."
+  (map (match-lambda
+         ((position note)
+          (make-fret position
+                     (find (lambda (scale-note)
+                             (eqv? note
+                                   (scale-note-note scale-note)))
+                           scale-notes))))
+       (zip (iota frets fret-offset)
+            (take (all-notes-from root)
+                  (+ frets fret-offset)))))
+
+(define* (fretboard tuning scale-notes
+                    #:optional (frets 7) (fret-offset 0))
+  "Generate a fretboard (a list of lists of frets) for an instrument
+with the given TUNING where the position of the notes of a given SCALE
+are indicated for as many FRETS as specified."
+  (map (cut string-frets <> scale-notes frets fret-offset)
+       (reverse tuning)))
+
+
+;;; Printing
+
+(define (print-fret fret)
+  (let ((note (fret-note fret)))
+    (format #t "-~3,,,'-,a-|"
+            (if note
+                 (if (zero? (scale-note-offset note))
+                     (string-upcase (symbol->string (scale-note-note note)))
+                     (scale-note-note note))
+                 "-"))))
+
+(define (print-frets frets)
+  (display "|")
+  (for-each print-fret frets)
+  (format #t "\n"))
+
+(define (print-fretboard fretboard)
+  (for-each print-frets fretboard))
+
+(define (print-stick fretboards)
+  (for-each (compose (lambda _ (format #t "\n"))
+                     print-fretboard)
+            fretboards))
diff --git a/scales/scales.scm b/scales/scales.scm
index 97b703e..ec8cf58 100644
--- a/scales/scales.scm
+++ b/scales/scales.scm
@@ -1,26 +1,18 @@
 (define-module (scales scales)
-  #:use-module (ice-9 match)
   #:use-module (srfi srfi-1)
-  #:use-module (srfi srfi-9)
-  #:use-module (srfi srfi-26))
+  #:use-module (scales utils)
+  #:export (steps->scale
 
-
-(define all-notes
-  (circular-list 'a 'ais 'b 'c 'cis 'd 'dis 'e 'f 'fis 'g 'gis))
-
-(define (all-notes-from root)
-  (find-tail (cut eqv? root <>) all-notes))
-
-
-;;; Scale notes
-
-;; A scale note is a note with a scale offset, e.g. a C# at the second
-;; scale position.
-(define-record-type <scale-note>
-  (make-scale-note note offset)
-  scale-note?
-  (note    scale-note-note)
-  (offset  scale-note-offset))
+            lydian
+            ionian
+            mixolydian
+            lydian-b7
+            altered
+            symmetrical-diminished
+            dorian
+            aeolian
+            phrygian
+            locrian))
 
 
 ;;; Common scales
@@ -59,82 +51,3 @@ root note and returns a list of scale notes."
   (steps->scale '(1 2 2 2 1 2 2)))
 (define locrian
   (steps->scale '(1 2 2 1 2 2 2)))
-
-
-;;; Tunings
-
-(define tuning-guitar
-  '(e a d g b e))
-
-(define tuning-grand-stick-matched-reciprocal-6+6
-  '((b e a d g c) (b e a d g c)))
-
-
-(define-record-type <fret>
-  (make-fret position note)
-  fret?
-  (position fret-position)
-  (note     fret-note))
-
-
-
-(define* (string-frets root scale-notes
-                       #:optional (frets 7) (fret-offset 0))
-  "Represent an instrument string as a list of FRETS frets.  Each fret
-contains a <FRET> object holding its position (starting from
-FRET-OFFSET) as well as the scale note matching one of the SCALE-NOTES
-at this position or #f."
-  (map (match-lambda
-         ((position note)
-          (make-fret position
-                     (find (lambda (scale-note)
-                             (eqv? note
-                                   (scale-note-note scale-note)))
-                           scale-notes))))
-       (zip (iota frets fret-offset)
-            (take (all-notes-from root)
-                  (+ frets fret-offset)))))
-
-(define* (fretboard tuning scale-notes
-                    #:optional (frets 7) (fret-offset 0))
-  "Generate a fretboard (a list of lists of frets) for an instrument
-with the given TUNING where the position of the notes of a given SCALE
-are indicated for as many FRETS as specified."
-  (map (lambda (root)
-         (string-frets root scale-notes frets fret-offset))
-       (reverse tuning)))
-
-
-;;; Printing
-(define (print-fret fret)
-  (let ((note (fret-note fret)))
-    (format #t "-~3,,,'-,a-|"
-            (if note
-                 (if (zero? (scale-note-offset note))
-                     (string-upcase (symbol->string (scale-note-note note)))
-                     (scale-note-note note))
-                 "-"))))
-
-(define (print-frets frets)
-  (display "|")
-  (for-each print-fret frets)
-  (format #t "\n"))
-
-(define (print-fretboard fretboard)
-  (for-each print-frets fretboard))
-
-(define (print-stick fretboards)
-  (for-each (compose (lambda _ (format #t "\n"))
-                     print-fretboard)
-            fretboards))
-
-
-
-;;; Examples
-
-(when #f
-  (print-fretboard (fretboard tuning-guitar (aeolian 'e) 7 5))
-  (print-stick
-   (map (lambda (string-group)
-          (fretboard string-group (aeolian 'e) 7 5))
-        tuning-grand-stick-matched-reciprocal-6+6)))
diff --git a/scales/utils.scm b/scales/utils.scm
new file mode 100644
index 0000000..6bb0a9d
--- /dev/null
+++ b/scales/utils.scm
@@ -0,0 +1,27 @@
+(define-module (scales utils)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-9)
+  #:use-module (srfi srfi-26)
+  #:export (all-notes-from
+
+            make-scale-note
+            scale-note-note
+            scale-note-offset))
+
+
+(define all-notes
+  (circular-list 'a 'ais 'b 'c 'cis 'd 'dis 'e 'f 'fis 'g 'gis))
+
+(define (all-notes-from root)
+  (find-tail (cut eqv? root <>) all-notes))
+
+
+;;; Scale notes
+
+;; A scale note is a note with a scale offset, e.g. a C# at the second
+;; scale position.
+(define-record-type <scale-note>
+  (make-scale-note note offset)
+  scale-note?
+  (note    scale-note-note)
+  (offset  scale-note-offset))