refactor(size): ♻️ redeclare simple in extension types to allow cha…

…ining (#438)

* refactor(size): ♻️ redeclare `simple` in extension types to allow expected chaining

* docs(example): 📖 add chaining `Size.simple` example

* refactor(size): ♻️ remove redundant `Size.` references

README.md

@@ -67,15 +67,16 @@ Pitch.parse('Eb3'); // E♭3
 Create an `Interval`:
 
 ```dart
-Interval.P4; // P4
 const Interval.imperfect(Size.tenth, ImperfectQuality.major); // M10
+Interval.d5; // d5
 Size.sixth.augmented; // A6
+Size.eleventh.simple.perfect; // P4
 ```
 
 Or turn it descending:
 
 ```dart
--Interval.m6; // m-6
+-Interval.m7; // m-7
 Interval.M3.descending(); // M-3
 ```
 

example/main.dart

@@ -21,11 +21,12 @@ void main() {
   Pitch.parse('Eb3'); // E♭3
 
   // Intervals
-  Interval.P4; // P4
   const Interval.imperfect(Size.tenth, ImperfectQuality.major); // M10
+  Interval.d5; // d5
   Size.sixth.augmented; // A6
+  Size.twelfth.simple.perfect; // P5
 
-  -Interval.m6; // m-6
+  -Interval.m7; // m-7
   Interval.M3.descending(); // M-3
 
   Note.c.interval(Note.g); // P5

lib/src/interval/size.dart

@@ -54,14 +54,14 @@ extension type const Size._(int size) implements int {
   /// [Size] to the corresponding [ImperfectQuality.minor] or
   /// [PerfectQuality.perfect] semitones.
   static const _sizeToSemitones = {
-    Size.unison: 0, // P
-    Size.second: 1, // m
-    Size.third: 3, // m
-    Size.fourth: 5, // P
-    Size.fifth: 7, // P
-    Size.sixth: 8, // m
-    Size.seventh: 10, // m
-    Size.octave: 12, // P
+    unison: 0, // P
+    second: 1, // m
+    third: 3, // m
+    fourth: 5, // P
+    fifth: 7, // P
+    sixth: 8, // m
+    seventh: 10, // m
+    octave: 12, // P
   };
 
   /// The [Size] that matches with [semitones] in [_sizeToSemitones].
@@ -107,10 +107,10 @@ extension type const Size._(int size) implements int {
   /// ```
   int get semitones {
     final simpleAbs = simple.abs();
-    final octaveShift = chromaticDivisions * (absShift ~/ Size.octave);
+    final octaveShift = chromaticDivisions * (absShift ~/ octave);
     // We exclude perfect octaves (simplified as 8) from the lookup to consider
     // them 0 (as if they were modulo `Size.octave`).
-    final size = Size(simpleAbs == Size.octave ? 1 : simpleAbs);
+    final size = Size(simpleAbs == octave ? 1 : simpleAbs);
 
     return (_sizeToSemitones[size]! + octaveShift) * sign;
   }
@@ -119,7 +119,7 @@ extension type const Size._(int size) implements int {
   int get absShift {
     final sizeAbs = abs();
 
-    return sizeAbs + sizeAbs ~/ Size.octave;
+    return sizeAbs + sizeAbs ~/ octave;
   }
 
   /// The [PerfectQuality.diminished] or [ImperfectQuality.diminished] interval
@@ -156,7 +156,7 @@ extension type const Size._(int size) implements int {
   /// Size.sixth.isPerfect == false
   /// (-Size.eleventh).isPerfect == true
   /// ```
-  bool get isPerfect => absShift % (Size.octave / 2) < 2;
+  bool get isPerfect => absShift % (octave / 2) < 2;
 
   /// Whether this [Size] is greater than [Size.octave].
   ///
@@ -169,7 +169,10 @@ extension type const Size._(int size) implements int {
   /// (-Size.eleventh).isCompound == true
   /// Size.thirteenth.isCompound == true
   /// ```
-  bool get isCompound => abs() > Size.octave;
+  bool get isCompound => abs() > octave;
+
+  static int _simple(Size size) =>
+      size.isCompound ? size.absShift.nonZeroMod(octave) * size.sign : size;
 
   /// The simplified version of this [Size].
   ///
@@ -180,9 +183,7 @@ extension type const Size._(int size) implements int {
   /// Size.octave.simple == Size.octave
   /// const Size(-22).simple == -Size.octave
   /// ```
-  Size get simple => Size(
-        isCompound ? absShift.nonZeroMod(Size.octave) * sign : size,
-      );
+  Size get simple => Size(_simple(this));
 
   /// This [Size] formatted as a string.
   String format({IntervalNotation system = IntervalNotation.standard}) =>
@@ -205,9 +206,7 @@ extension type const PerfectSize._(int size) implements Size {
   const PerfectSize(this.size)
       // Copied from [Size.isPerfect] to allow const.
       : assert(
-          ((size < 0 ? 0 - size : size) + (size < 0 ? 0 - size : size) ~/ 8) %
-                  4 <
-              2,
+          ((size < 0 ? -size : size) + (size < 0 ? -size : size) ~/ 8) % 4 < 2,
           'Interval must be perfect.',
         );
 
@@ -221,6 +220,9 @@ extension type const PerfectSize._(int size) implements Size {
   /// ```
   Interval get perfect => Interval.perfect(this);
 
+  @redeclare
+  PerfectSize get simple => PerfectSize(Size._simple(this));
+
   /// The negation of this [PerfectSize].
   ///
   /// Example:
@@ -238,9 +240,7 @@ extension type const ImperfectSize._(int size) implements Size {
   const ImperfectSize(this.size)
       // Copied from [Size.isPerfect] to allow const.
       : assert(
-          ((size < 0 ? 0 - size : size) + (size < 0 ? 0 - size : size) ~/ 8) %
-                  4 >=
-              2,
+          ((size < 0 ? -size : size) + (size < 0 ? -size : size) ~/ 8) % 4 >= 2,
           'Interval must be imperfect.',
         );
 
@@ -264,6 +264,9 @@ extension type const ImperfectSize._(int size) implements Size {
   /// ```
   Interval get minor => Interval.imperfect(this, ImperfectQuality.minor);
 
+  @redeclare
+  ImperfectSize get simple => ImperfectSize(Size._simple(this));
+
   /// The negation of this [ImperfectSize].
   ///
   /// Example:

test/src/interval/size_test.dart

@@ -50,6 +50,7 @@ void main() {
         expect(Size.unison.perfect, Interval.P1);
         expect(Size.fourth.perfect, Interval.P4);
         expect((-Size.fifth).perfect, -Interval.P5);
+        expect(Size.twelfth.simple.perfect, Interval.P5);
       });
     });
 
@@ -58,6 +59,7 @@ void main() {
         expect(Size.second.major, Interval.M2);
         expect(Size.sixth.major, Interval.M6);
         expect((-Size.ninth).major, -Interval.M9);
+        expect(Size.thirteenth.simple.major, Interval.M6);
       });
     });
 
@@ -66,6 +68,7 @@ void main() {
         expect(Size.third.minor, Interval.m3);
         expect(Size.seventh.minor, Interval.m7);
         expect((-Size.sixth).minor, -Interval.m6);
+        expect(Size.ninth.simple.minor, Interval.m2);
       });
     });
 
@@ -74,6 +77,7 @@ void main() {
         expect(Size.second.diminished, Interval.d2);
         expect(Size.fifth.diminished, Interval.d5);
         expect((-Size.seventh).diminished, -Interval.d7);
+        expect(Size.eleventh.simple.diminished, Interval.d4);
       });
     });
 
@@ -82,6 +86,7 @@ void main() {
         expect(Size.third.augmented, Interval.A3);
         expect(Size.fourth.augmented, Interval.A4);
         expect((-Size.sixth).augmented, -Interval.A6);
+        expect(Size.twelfth.simple.augmented, Interval.A5);
       });
     });
   });