Merge 74e9062 into 1028adf

lib/src/scale/scale_pattern.dart

@@ -5,6 +5,8 @@ import 'package:meta/meta.dart' show immutable;
 import '../harmony/chord_pattern.dart';
 import '../interval/interval.dart';
 import '../interval/interval_class.dart';
+import '../music.dart';
+import '../note/pitch_class.dart';
 import '../scalable.dart';
 import 'scale.dart';
 import 'scale_degree.dart';
@@ -249,6 +251,37 @@ final class ScalePattern {
     return major;
   }
 
+  /// Creates a new [ScalePattern] from a binary [sequence] in integer form.
+  ///
+  /// This method and [ScalePattern.toBinary] are inverses of each other.
+  ///
+  /// Example:
+  /// ```dart
+  /// ScalePattern.fromBinary(int.parse('101010110101', radix: 2))
+  ///   == ScalePattern.major
+  /// ```
+  factory ScalePattern.fromBinary(int sequence) {
+    assert(sequence > 0, 'Sequence must be greater than 0');
+
+    return Scale([
+      for (int i = 0; i < chromaticDivisions; i++)
+        if (sequence & 1 << i != 0) PitchClass(i),
+      PitchClass.c,
+    ]).pattern;
+  }
+
+  /// Returns the binary representation of this [ScalePattern].
+  ///
+  /// This method and [ScalePattern.fromBinary] are inverses of each other.
+  ///
+  /// Example:
+  /// ```dart
+  /// ScalePattern.major.toBinary() == int.parse('101010110101', radix: 2)
+  /// ```
+  int toBinary() => on(PitchClass.c)
+      .degrees
+      .fold(0, (sequence, scalable) => sequence | 1 << scalable.semitones);
+
   /// The length of this [ScalePattern].
   ///
   /// Example:

test/src/scale/scale_pattern_test.dart

@@ -39,6 +39,32 @@ void main() {
       });
     });
 
+    group('.fromBinary()', () {
+      test('creates a new ScalePattern from a binary sequence', () {
+        expect(
+          ScalePattern.fromBinary(int.parse('101010110101', radix: 2)),
+          ScalePattern.major,
+        );
+        expect(
+          ScalePattern.fromBinary(int.parse('111111111111', radix: 2)),
+          ScalePattern.chromatic,
+        );
+      });
+    });
+
+    group('.toBinary()', () {
+      test('returns the binary representation of this ScalePattern', () {
+        expect(
+          ScalePattern.major.toBinary(),
+          int.parse('101010110101', radix: 2),
+        );
+        expect(
+          ScalePattern.chromatic.toBinary(),
+          int.parse('111111111111', radix: 2),
+        );
+      });
+    });
+
     group('.length', () {
       test('returns the length of this ScalePattern', () {
         expect(ScalePattern.minorPentatonic.length, 5);