initial commit with cache support & example

2022-02-07 00:11:15 +06:00
commit c7169b04c7
65 changed files with 7155 additions and 0 deletions
@@ -0,0 +1,45 @@
+bool notNull(Object? any) {
+  return any != null;
+}
+
+Map<String, dynamic>? _recursivelyAddAll(
+  Map<String, dynamic>? target,
+  Map<String, dynamic>? source,
+) {
+  target = Map<String, dynamic>.from(target ?? {});
+  source?.forEach((String key, dynamic value) {
+    if (target!.containsKey(key) &&
+        target[key] is Map<String, dynamic> &&
+        value != null &&
+        value is Map<String, dynamic>) {
+      target[key] = _recursivelyAddAll(
+        target[key] as Map<String, dynamic>,
+        value,
+      );
+    } else {
+      // Lists and nulls overwrite target as if they were normal scalars
+      target[key] = value;
+    }
+  });
+  return target;
+}
+
+/// Deeply merges `maps` into a new map, merging nested maps recursively.
+///
+/// Paths in the rightmost maps override those in the earlier ones, so:
+/// ```
+/// print(deeplyMergeLeft([
+///   {'keyA': 'a1'},
+///   {'keyA': 'a2', 'keyB': 'b2'},
+///   {'keyB': 'b3'}
+/// ]));
+/// // { keyA: a2, keyB: b3 }
+/// ```
+///
+/// Conflicting [List]s are overwritten like scalars
+Map<String, dynamic>? deeplyMergeLeft(
+  Iterable<Map<String, dynamic>?> maps,
+) {
+  // prepend an empty literal for functional immutability
+  return (<Map<String, dynamic>?>[{}]..addAll(maps)).reduce(_recursivelyAddAll);
+}