refactor: sync

mobile-v2/lib/utils/collection_util.dart

@@ -0,0 +1,52 @@
+// ignore_for_file: avoid-unsafe-collection-methods
+
+class CollectionUtil {
+  const CollectionUtil();
+
+  static int compareToNullable<T extends Comparable>(T? a, T? b) {
+    if (a == null) {
+      return 1;
+    }
+    if (b == null) {
+      return -1;
+    }
+    return a.compareTo(b);
+  }
+
+  /// Find the difference between the two sorted lists [first] and [second]
+  /// Results are passed as callbacks back to the caller during the comparison
+  static bool diffSortedLists<T>(
+    List<T> first,
+    List<T> second, {
+    required Comparator<T> compare,
+    required bool Function(T a, T b) both,
+    required void Function(T a) onlyFirst,
+    required void Function(T b) onlySecond,
+  }) {
+    bool diff = false;
+    int i = 0, j = 0;
+
+    for (; i < first.length && j < second.length;) {
+      final int order = compare(first[i], second[j]);
+      if (order == 0) {
+        diff |= both(first[i++], second[j++]);
+      } else if (order < 0) {
+        onlyFirst(first[i++]);
+        diff = true;
+      } else if (order > 0) {
+        onlySecond(second[j++]);
+        diff = true;
+      }
+    }
+
+    diff |= i < first.length || j < second.length;
+
+    for (; i < first.length; i++) {
+      onlyFirst(first[i]);
+    }
+    for (; j < second.length; j++) {
+      onlySecond(second[j]);
+    }
+    return diff;
+  }
+}