diff --git a/sugar/lib/crdt.dart b/sugar/lib/crdt.dart
index 5ee75257..18bcebe5 100644
--- a/sugar/lib/crdt.dart
+++ b/sugar/lib/crdt.dart
@@ -1,2 +1,2 @@
 export 'src/crdt/string_index.dart';
-export 'src/crdt/string_index_set.dart';
+export 'src/crdt/string_indexed_list.dart';
diff --git a/sugar/lib/src/crdt/string_index_set.dart b/sugar/lib/src/crdt/string_index_set.dart
deleted file mode 100644
index b888803e..00000000
--- a/sugar/lib/src/crdt/string_index_set.dart
+++ /dev/null
@@ -1,64 +0,0 @@
-import 'dart:collection';
-
-import 'package:sugar/sugar.dart';
-
-class StringIndexSet<E> extends Iterable<E> {
-
-  /// Whether to strictly validate a string index's format. True by default.
-  final bool strict;
-
-  final SplayTreeMap<String, E> _map;
-  final HashMap<E, String> _inverse;
-  final List<E> _list;
-  final bool Function(E, E) _equals;
-  final int Function(E) _hash;
-
-  StringIndexSet._(
-    this._map,
-    this._inverse,
-    this._list,
-    this._equals,
-    this._hash, {
-    required this.strict,
-  });
-
-
-  void operator []= (Object index, E element) {
-    if (_inverse.containsKey(element)) {
-      return;
-    }
-
-    switch (index) {
-      case final String index:
-        if (_map.firstValueAfter(index) case final after?) {
-          _list.insert(_list.indexWhere((e) => _equals(e, after)), element);
-
-        } else {
-          _list.add(element);
-        }
-
-        _map[index] = element;
-        _inverse[element] = index;
-
-        // Different semantics between map and list
-      case final int index when index < _list.length:
-        final min = _inverse[_list.elementAtOrNull(index - 1)] ?? StringIndex.min;
-        final max = _inverse[_list.elementAtOrNull(index + 1)] ?? StringIndex.max;
-        final string = StringIndex.between(min: min, max: max, strict: strict);
-        _list.insert(index, element);
-
-    }
-  }
-
-
-  @override
-  Iterator<E> get iterator => _list.iterator;
-
-  @override
-  E get first => _list.first;
-
-  set first(E first) {
-
-  }
-
-}
diff --git a/sugar/lib/src/crdt/string_indexed_list.dart b/sugar/lib/src/crdt/string_indexed_list.dart
new file mode 100644
index 00000000..490e1615
--- /dev/null
+++ b/sugar/lib/src/crdt/string_indexed_list.dart
@@ -0,0 +1,78 @@
+import 'dart:collection';
+
+import 'package:sugar/sugar.dart';
+
+class Sil<E> extends Iterable<E> {
+
+  /// Whether to strictly validate a string index's format. True by default.
+  final bool strict;
+
+  final SplayTreeMap<String, E> _map;
+  final HashMap<E, String> _inverse;
+  final List<E> _list;
+  final bool Function(E, E) _equals;
+  final int Function(E) _hash;
+
+  Sil._(
+    this._map,
+    this._inverse,
+    this._list,
+    this._equals,
+    this._hash, {
+    required this.strict,
+  });
+
+
+  bool put(String index, E element) {
+    if (_inverse.containsKey(element)) {
+      return false;
+    }
+
+    final old = _map[index];
+    if (old == null) {
+      if (_map.firstValueAfter(index) case final after?) {
+        _list.insert(_list.indexWhere((e) => _equals(e, after)), element);
+
+      } else {
+        _list.add(element);
+      }
+
+      _map[index] = element;
+      _inverse[element] = index;
+
+    } else {
+      _map[index] = element;
+      _inverse.remove(old);
+      _inverse[element] = index;
+      _list[_list.indexWhere((e) => _equals(e, old))] = element;
+    }
+
+    return true;
+  }
+
+
+  int indexOf(E element) => _list.indexOf(element);
+
+  String? stringIndexOf(E element) => _inverse[element];
+
+
+  void operator []= (int index, E element) {
+    if (_inverse.containsKey(element)) {
+      return;
+    }
+
+    final old = _list[index];
+    final string = _inverse.remove(old)!;
+
+    _map[string] = element;
+    _inverse[element] = string;
+    _list[index] = element;
+  }
+
+  E operator [] (int index) => _list[index];
+
+
+  @override
+  Iterator<E> get iterator => _list.iterator;
+
+}
diff --git a/sugar/test/src/crdt/string_index_test.dart b/sugar/test/src/crdt/string_index_test.dart
index 395a0019..73e00eb0 100644
--- a/sugar/test/src/crdt/string_index_test.dart
+++ b/sugar/test/src/crdt/string_index_test.dart
@@ -1,6 +1,5 @@
 import 'dart:math';
 
-import 'package:sugar/src/crdt/string_index.dart';
 import 'package:sugar/sugar.dart';
 import 'package:test/test.dart';