computed_collections: fromPiecewiseComputed

mstniy · Oct 2, 2024 · e967614 · e967614
1 parent 7f050c3
commit e967614
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Showing 3 changed files with 16 additions and 2 deletions.
diff --git a/packages/computed_collections/lib/computedmap.dart b/packages/computed_collections/lib/computedmap.dart
@@ -42,6 +42,10 @@ abstract class ComputedMap<K, V> {
   factory ComputedMap.fromPiecewise(Iterable<K> domain, V Function(K key) f) =>
       PiecewiseComputedMap(domain, f);
 
+  factory ComputedMap.fromPiecewiseComputed(
+          Iterable<K> domain, Computed<V> Function(K key) f) =>
+      ComputedMap.fromPiecewise(domain, f).mapValuesComputed((_, c) => c);
+
   /// A computation representing the last change event on this map.
   Computed<ChangeEvent<K, V>> get changes;
 

diff --git a/packages/computed_collections/lib/src/piecewise.dart b/packages/computed_collections/lib/src/piecewise.dart
@@ -14,11 +14,12 @@ class PiecewiseComputedMap<K, V>
   // This is not powerful enough to represent uncountably infinite domains :(
   final Iterable<K> _domain;
   final V Function(K) _f;
-  final _keyCache = ComputationCache<K, Option<V>>();
+  final _keyCache = ComputationCache<K, Option<V>>(assertIdempotent: false);
   final _containsValueCache = ComputationCache<V, bool>();
 
   PiecewiseComputedMap(this._domain, this._f) {
-    snapshot = $(() => IMap.fromKeys(keys: _domain, valueMapper: _f));
+    snapshot = Computed(() => IMap.fromKeys(keys: _domain, valueMapper: _f),
+        assertIdempotent: false);
   }
 
   Option<V> Function() _getKeyComputation(K key) =>

diff --git a/packages/computed_collections/test/piecewise_test.dart b/packages/computed_collections/test/piecewise_test.dart
@@ -1,3 +1,4 @@
+import 'package:computed/computed.dart';
 import 'package:computed_collections/computedmap.dart';
 import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:test/test.dart';
@@ -58,4 +59,12 @@ void main() {
     expect(await getValue(m[1]), 0);
     expect(await getValue(m[-1]), null);
   });
+
+  test('fromPiecewiseComputed works', () async {
+    expect(
+        await getValue(
+            ComputedMap.fromPiecewiseComputed([0, 1], (x) => $(() => x + 1))
+                .snapshot),
+        {0: 1, 1: 2}.lock);
+  });
 }