Cache hash codes for Sass strings and numbers

These values are often stored in maps, so caching their hash codes
seems to be net valuable.

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.43.3
+
+* Improve performance.
+
 ## 1.43.2
 
 * Improve the error message when the default namespace of a `@use` rule is not

lib/src/value/number.dart

@@ -181,6 +181,12 @@ abstract class SassNumber extends Value {
   /// integer value, or [assertInt] to do both at once.
   final num value;
 
+  /// The cached hash code for this number, if it's been computed.
+  ///
+  /// @nodoc
+  @protected
+  int? hashCache;
+
   /// This number's numerator units.
   List<String> get numeratorUnits;
 
@@ -826,7 +832,7 @@ abstract class SassNumber extends Value {
     }
   }
 
-  int get hashCode => fuzzyHashCode(value *
+  int get hashCode => hashCache ??= fuzzyHashCode(value *
       _canonicalMultiplier(numeratorUnits) /
       _canonicalMultiplier(denominatorUnits));
 

lib/src/value/number/single_unit.dart

@@ -160,5 +160,6 @@ class SingleUnitSassNumber extends SassNumber {
     }
   }
 
-  int get hashCode => fuzzyHashCode(value * canonicalMultiplierForUnit(_unit));
+  int get hashCode =>
+      hashCache ??= fuzzyHashCode(value * canonicalMultiplierForUnit(_unit));
 }

lib/src/value/number/unitless.dart

@@ -142,5 +142,5 @@ class UnitlessSassNumber extends SassNumber {
   bool operator ==(Object other) =>
       other is UnitlessSassNumber && fuzzyEquals(value, other.value);
 
-  int get hashCode => fuzzyHashCode(value);
+  int get hashCode => hashCache ??= fuzzyHashCode(value);
 }

lib/src/value/string.dart

@@ -55,6 +55,9 @@ class SassString extends Value {
   /// efficient.
   late final int sassLength = text.runes.length;
 
+  /// The cached hash code for this number, if it's been computed.
+  int? _hashCache;
+
   /// @nodoc
   @internal
   bool get isSpecialNumber {
@@ -189,7 +192,7 @@ class SassString extends Value {
 
   bool operator ==(Object other) => other is SassString && text == other.text;
 
-  int get hashCode => text.hashCode;
+  int get hashCode => _hashCache ??= text.hashCode;
 
   /// Throws a [SassScriptException] with the given [message].
   SassScriptException _exception(String message, [String? name]) =>

pkg/sass_api/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.0.0-beta.17
+
+* No user-visible changes.
+
 ## 1.0.0-beta.16
 
 * No user-visible changes.

pkg/sass_api/pubspec.yaml

@@ -2,15 +2,15 @@ name: sass_api
 # Note: Every time we add a new Sass AST node, we need to bump the *major*
 # version because it's a breaking change for anyone who's implementing the
 # visitor interface(s).
-version: 1.0.0-beta.16
+version: 1.0.0-beta.17
 description: Additional APIs for Dart Sass.
 homepage: https://github.com/sass/dart-sass
 
 environment:
   sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
-  sass: 1.43.2
+  sass: 1.43.3
 
 dependency_overrides:
   sass: {path: ../..}

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass
-version: 1.43.2
+version: 1.43.3
 description: A Sass implementation in Dart.
 homepage: https://github.com/sass/dart-sass