albertms10 · albertms10 · Mar 7, 2024 · Mar 7, 2024
@@ -1,4 +1,5 @@
-import 'package:collection/collection.dart' show ListEquality;
+import 'package:collection/collection.dart'
+    show ListEquality, UnmodifiableListView;
 import 'package:meta/meta.dart' show immutable;
 
 import '../chordable.dart';
@@ -21,14 +22,16 @@ import 'chord_pattern.dart';
 class Chord<T extends Scalable<T>>
     with Chordable<Chord<T>>
     implements Transposable<Chord<T>> {
+  final List<T> _items;
+
   /// The [Scalable] items this [Chord] is built of.
-  final List<T> items;
+  List<T> get items => UnmodifiableListView(_items);
 
-  /// Creates a new [Chord] from [items].
-  const Chord(this.items);
+  /// Creates a new [Chord] from [_items].
+  const Chord(this._items);
 
   /// The root [Scalable] of this [Chord].
-  T get root => items.first;
+  T get root => _items.first;
 
   /// The [ChordPattern] for this [Chord].
   ///
@@ -45,15 +48,15 @@ class Chord<T extends Scalable<T>>
   ///   == ChordPattern.majorTriad.add7().add9()
   /// ```
   ChordPattern get pattern =>
-      ChordPattern.fromIntervalSteps(items.intervalSteps);
+      ChordPattern.fromIntervalSteps(_items.intervalSteps);
 
   /// The modifier [T]s from the root note.
   ///
   /// Example:
   /// ```dart
   /// Note.a.majorTriad.add7().add9().modifiers == const [Note.g, Note.b]
   /// ```
-  List<T> get modifiers => items.skip(3).toList();
+  List<T> get modifiers => _items.skip(3).toList();
 
   /// Returns a new [Chord] with an [ImperfectQuality.diminished] root triad.
   ///
@@ -117,15 +120,15 @@ class Chord<T extends Scalable<T>>
   /// ```
   @override
   Chord<T> transposeBy(Interval interval) =>
-      Chord(items.transposeBy(interval).toList());
+      Chord(_items.transposeBy(interval).toList());
 
   @override
-  String toString() => '$root ${pattern.abbreviation} (${items.join(' ')})';
+  String toString() => '$root ${pattern.abbreviation} (${_items.join(' ')})';
 
   @override
   bool operator ==(Object other) =>
-      other is Chord<T> && ListEquality<T>().equals(items, other.items);
+      other is Chord<T> && ListEquality<T>().equals(_items, other._items);
 
   @override
-  int get hashCode => Object.hashAll(items);
+  int get hashCode => Object.hashAll(_items);
 }
@@ -1,5 +1,5 @@
 import 'package:collection/collection.dart'
-    show IterableExtension, ListEquality;
+    show IterableExtension, ListEquality, UnmodifiableListView;
 import 'package:meta/meta.dart' show immutable;
 
 import '../chordable.dart';
@@ -16,11 +16,13 @@ import 'chord.dart';
 /// * [Interval].
 @immutable
 class ChordPattern with Chordable<ChordPattern> {
+  final List<Interval> _intervals;
+
   /// The intervals from the root note.
-  final List<Interval> intervals;
+  List<Interval> get intervals => UnmodifiableListView(_intervals);
 
-  /// Creates a new [ChordPattern] from [intervals].
-  const ChordPattern(this.intervals);
+  /// Creates a new [ChordPattern] from [_intervals].
+  const ChordPattern(this._intervals);
 
   /// A diminished triad [ChordPattern].
   static const diminishedTriad = ChordPattern([Interval.m3, Interval.d5]);
@@ -77,7 +79,7 @@ class ChordPattern with Chordable<ChordPattern> {
   ///   == const Chord([Note.c, Note.e, Note.g])
   /// ```
   Chord<T> on<T extends Scalable<T>>(T scalable) => Chord(
-        intervals.fold(
+        _intervals.fold(
           [scalable],
           (chordItems, interval) =>
               [...chordItems, scalable.transposeBy(interval)],
@@ -90,7 +92,7 @@ class ChordPattern with Chordable<ChordPattern> {
   /// ```dart
   /// ChordPattern.majorTriad.add7().add9().rootTriad == ChordPattern.majorTriad
   /// ```
-  ChordPattern get rootTriad => ChordPattern(intervals.sublist(0, 2));
+  ChordPattern get rootTriad => ChordPattern(_intervals.sublist(0, 2));
 
   /// Whether this [ChordPattern] is [ImperfectQuality.diminished].
   bool get isDiminished => rootTriad == diminishedTriad;
@@ -111,7 +113,7 @@ class ChordPattern with Chordable<ChordPattern> {
   /// ChordPattern.majorTriad.add7().add9().modifiers
   ///   == const [Interval.m7, Interval.M9]
   /// ```
-  List<Interval> get modifiers => intervals.skip(2).toList();
+  List<Interval> get modifiers => _intervals.skip(2).toList();
 
   /// Returns a new [ChordPattern] with an [ImperfectQuality.diminished] root
   /// triad.
@@ -123,7 +125,7 @@ class ChordPattern with Chordable<ChordPattern> {
   /// ```
   @override
   ChordPattern get diminished =>
-      ChordPattern([...diminishedTriad.intervals, ...modifiers]);
+      ChordPattern([...diminishedTriad._intervals, ...modifiers]);
 
   /// Returns a new [ChordPattern] with an [ImperfectQuality.minor] root
   /// triad.
@@ -135,7 +137,7 @@ class ChordPattern with Chordable<ChordPattern> {
   /// ```
   @override
   ChordPattern get minor =>
-      ChordPattern([...minorTriad.intervals, ...modifiers]);
+      ChordPattern([...minorTriad._intervals, ...modifiers]);
 
   /// Returns a new [ChordPattern] with an [ImperfectQuality.major] root
   /// triad.
@@ -147,7 +149,7 @@ class ChordPattern with Chordable<ChordPattern> {
   /// ```
   @override
   ChordPattern get major =>
-      ChordPattern([...majorTriad.intervals, ...modifiers]);
+      ChordPattern([...majorTriad._intervals, ...modifiers]);
 
   /// Returns a new [ChordPattern] with an [ImperfectQuality.augmented] root
   /// triad.
@@ -159,13 +161,13 @@ class ChordPattern with Chordable<ChordPattern> {
   /// ```
   @override
   ChordPattern get augmented =>
-      ChordPattern([...augmentedTriad.intervals, ...modifiers]);
+      ChordPattern([...augmentedTriad._intervals, ...modifiers]);
 
   /// Returns a new [ChordPattern] adding [interval].
   @override
   ChordPattern add(Interval interval, {Set<int>? replaceSizes}) {
     final sizesToReplace = [interval.size, ...?replaceSizes];
-    final filteredIntervals = intervals.whereNot(
+    final filteredIntervals = _intervals.whereNot(
       (chordInterval) => sizesToReplace.contains(chordInterval.size),
     );
 
@@ -189,13 +191,13 @@ class ChordPattern with Chordable<ChordPattern> {
   }
 
   @override
-  String toString() => '$abbreviation (${intervals.join(' ')})';
+  String toString() => '$abbreviation (${_intervals.join(' ')})';
 
   @override
   bool operator ==(Object other) =>
       other is ChordPattern &&
-      const ListEquality<Interval>().equals(intervals, other.intervals);
+      const ListEquality<Interval>().equals(_intervals, other._intervals);
 
   @override
-  int get hashCode => Object.hashAll(intervals);
+  int get hashCode => Object.hashAll(_intervals);
 }
@@ -1,4 +1,5 @@
-import 'package:collection/collection.dart' show ListEquality;
+import 'package:collection/collection.dart'
+    show ListEquality, UnmodifiableListView;
 import 'package:meta/meta.dart' show immutable;
 
 import '../interval/quality.dart';
@@ -13,11 +14,13 @@ import '../scale/scale_degree.dart';
 /// * [ScaleDegree].
 @immutable
 class HarmonicFunction {
+  final List<ScaleDegree> _scaleDegrees;
+
   /// The scale degrees that define this [HarmonicFunction].
-  final List<ScaleDegree> scaleDegrees;
+  List<ScaleDegree> get scaleDegrees => UnmodifiableListView(_scaleDegrees);
 
-  /// Creates a new [HarmonicFunction] from [scaleDegrees].
-  const HarmonicFunction(this.scaleDegrees);
+  /// Creates a new [HarmonicFunction] from [_scaleDegrees].
+  const HarmonicFunction(this._scaleDegrees);
 
   /// A I (tonic) degree [HarmonicFunction].
   static const i = HarmonicFunction([ScaleDegree.i]);
@@ -59,7 +62,7 @@ class HarmonicFunction {
   String toString({
     ScaleDegreeNotation system = ScaleDegreeNotation.standard,
   }) =>
-      scaleDegrees
+      _scaleDegrees
           .map((scaleDegree) => scaleDegree.toString(system: system))
           .join('/');
 
@@ -76,14 +79,14 @@ class HarmonicFunction {
   ///      ])
   /// ```
   HarmonicFunction operator /(HarmonicFunction other) =>
-      HarmonicFunction([...scaleDegrees, ...other.scaleDegrees]);
+      HarmonicFunction([..._scaleDegrees, ...other._scaleDegrees]);
 
   @override
   bool operator ==(Object other) =>
       other is HarmonicFunction &&
       const ListEquality<ScaleDegree>()
-          .equals(scaleDegrees, other.scaleDegrees);
+          .equals(_scaleDegrees, other._scaleDegrees);
 
   @override
-  int get hashCode => Object.hashAll(scaleDegrees);
+  int get hashCode => Object.hashAll(_scaleDegrees);
 }
@@ -1,5 +1,10 @@
 import 'package:collection/collection.dart'
-    show IterableEquality, IterableExtension, ListEquality;
+    show
+        IterableEquality,
+        IterableExtension,
+        ListEquality,
+        UnmodifiableListView,
+        UnmodifiableMapView;
 import 'package:meta/meta.dart' show immutable;
 import 'package:music_notes/utils.dart';
 
@@ -18,12 +23,14 @@ import 'mode.dart';
 /// * [Key].
 @immutable
 final class KeySignature implements Comparable<KeySignature> {
+  final List<Note> _notes;
+
   /// The set of [Note] that define this [KeySignature], which may include
   /// cancellation [Accidental.natural]s.
-  final List<Note> notes;
+  List<Note> get notes => UnmodifiableListView(_notes);
 
-  /// Creates a new [KeySignature] from [notes].
-  const KeySignature(this.notes);
+  /// Creates a new [KeySignature] from [_notes].
+  const KeySignature(this._notes);
 
   /// An empty [KeySignature].
   static const empty = KeySignature([]);
@@ -62,7 +69,7 @@ final class KeySignature implements Comparable<KeySignature> {
   /// KeySignature.empty.accidental == Accidental.natural
   /// ```
   Accidental get accidental =>
-      clean.notes.firstOrNull?.accidental ?? Accidental.natural;
+      clean._notes.firstOrNull?.accidental ?? Accidental.natural;
 
   /// Returns a new [KeySignature] without cancellation [Accidental.natural]s.
   ///
@@ -74,7 +81,7 @@ final class KeySignature implements Comparable<KeySignature> {
   ///   == KeySignature([Note.f.sharp, Note.c.sharp, Note.g.sharp])
   /// ```
   KeySignature get clean =>
-      KeySignature(notes.where((note) => !note.accidental.isNatural).toList());
+      KeySignature(_notes.where((note) => !note.accidental.isNatural).toList());
 
   /// The fifths distance of this [KeySignature].
   ///
@@ -88,7 +95,7 @@ final class KeySignature implements Comparable<KeySignature> {
   int? get distance {
     if (accidental.isNatural) return 0;
 
-    final cleanNotes = clean.notes;
+    final cleanNotes = clean._notes;
     final apparentDistance = cleanNotes.length * accidental.semitones.sign;
     final apparentFirstNote =
         accidental.isFlat ? _firstCanonicalFlatNote : _firstCanonicalSharpNote;
@@ -129,12 +136,15 @@ final class KeySignature implements Comparable<KeySignature> {
   /// ```
   Map<TonalMode, Key> get keys {
     final distance = this.distance;
-    if (distance == null) return {};
+    if (distance == null) return const {};
 
     final rootNote = Interval.P5.circleFrom(Note.c, distance: distance).last;
     final major = rootNote.major;
 
-    return {TonalMode.major: major, TonalMode.minor: major.relative};
+    return UnmodifiableMapView({
+      TonalMode.major: major,
+      TonalMode.minor: major.relative,
+    });
   }
 
   static const _noteNotation = EnglishNoteNotation(showNatural: true);
@@ -161,7 +171,7 @@ final class KeySignature implements Comparable<KeySignature> {
   }
 
   @override
-  String toString() => '$distance (${notes.map(
+  String toString() => '$distance (${_notes.map(
         (note) => note.toString(system: _noteNotation),
       ).join(' ')})';
 
@@ -181,28 +191,28 @@ final class KeySignature implements Comparable<KeySignature> {
     if (this == empty) return other;
 
     final cancelledNotes = accidental == other.accidental
-        ? clean.notes.whereNot(other.notes.contains)
-        : clean.notes;
+        ? clean._notes.whereNot(other._notes.contains)
+        : clean._notes;
 
     return KeySignature([
       ...cancelledNotes.map((note) => note.natural).toSet(),
-      ...other.notes,
+      ...other._notes,
     ]);
   }
 
   @override
   bool operator ==(Object other) =>
       other is KeySignature &&
-      const ListEquality<Note>().equals(notes, other.notes);
+      const ListEquality<Note>().equals(_notes, other._notes);
 
   @override
-  int get hashCode => Object.hash(notes, accidental);
+  int get hashCode => Object.hash(_notes, accidental);
 
   @override
   int compareTo(KeySignature other) => compareMultiple([
         () => accidental.compareTo(other.accidental),
         () =>
-            notes.length.compareTo(other.notes.length) *
+            _notes.length.compareTo(other._notes.length) *
             accidental.semitones.nonZeroSign,
       ]);
 }