refactor: high-level loops

lib/encryption/ssss.dart

@@ -121,10 +121,7 @@ class SSSS {
   static Uint8List decodeRecoveryKey(String recoveryKey) {
     final result = base58.decode(recoveryKey.replaceAll(' ', ''));
 
-    var parity = 0;
+    final parity = result.fold(0, (a, b) => a ^ b);
-    for (final b in result) {
-      parity ^= b;
-    }
     if (parity != 0) {
       throw Exception('Incorrect parity');
     }
@@ -144,15 +141,8 @@ class SSSS {
   }
 
   static String encodeRecoveryKey(Uint8List recoveryKey) {
-    final keyToEncode = <int>[];
+    final keyToEncode = <int>[...olmRecoveryKeyPrefix, ...recoveryKey];
-    for (final b in olmRecoveryKeyPrefix) {
+    final parity = keyToEncode.fold(0, (a, b) => a ^ b);
-      keyToEncode.add(b);
-    }
-    keyToEncode.addAll(recoveryKey);
-    var parity = 0;
-    for (final b in keyToEncode) {
-      parity ^= b;
-    }
     keyToEncode.add(parity);
     // base58-encode and add a space every four chars
     return base58
@@ -233,10 +223,12 @@ class SSSS {
     const keyidByteLength = 24;
 
     // make sure we generate a unique key id
-    var keyId = base64.encode(SecureRandom(keyidByteLength).bytes);
+    final keyId = () sync* {
-    while (getKey(keyId) != null) {
+      for (;;) {
-      keyId = base64.encode(SecureRandom(keyidByteLength).bytes);
+        yield base64.encode(SecureRandom(keyidByteLength).bytes);
-    }
+      }
+    }()
+        .firstWhere((keyId) => getKey(keyId) == null);
 
     final accountDataType = EventTypes.secretStorageKey(keyId);
     // noooow we set the account data
@@ -553,11 +545,7 @@ class SSSS {
       return null;
     }
     if (data.content['encrypted'] is Map) {
-      final Set keys = <String>{};
+      return data.content['encrypted'].keys.toSet();
-      for (final key in data.content['encrypted'].keys) {
-        keys.add(key);
-      }
-      return keys;
     }
     return null;
   }

lib/src/client.dart

@@ -227,15 +227,15 @@ class Client extends MatrixApi {
   }
 
   Room getRoomByAlias(String alias) {
-    for (var i = 0; i < rooms.length; i++) {
+    for (final room in rooms) {
-      if (rooms[i].canonicalAlias == alias) return rooms[i];
+      if (room.canonicalAlias == alias) return room;
     }
     return null;
   }
 
   Room getRoomById(String id) {
-    for (var j = 0; j < rooms.length; j++) {
+    for (final room in rooms) {
-      if (rooms[j].id == id) return rooms[j];
+      if (room.id == id) return room;
     }
     return null;
   }
@@ -269,15 +269,12 @@ class Client extends MatrixApi {
             .id;
       }
     }
-    for (var i = 0; i < rooms.length; i++) {
+    for (final room in rooms) {
-      if (rooms[i].membership == Membership.invite &&
+      if (room.membership == Membership.invite &&
-          rooms[i].getState(EventTypes.RoomMember, userID)?.senderId ==
+          room.getState(EventTypes.RoomMember, userID)?.senderId == userId &&
-              userId &&
+          room.getState(EventTypes.RoomMember, userID).content['is_direct'] ==
-          rooms[i]
-                  .getState(EventTypes.RoomMember, userID)
-                  .content['is_direct'] ==
               true) {
-        return rooms[i].id;
+        return room.id;
       }
     }
     return null;
@@ -1216,23 +1213,23 @@ class Client extends MatrixApi {
   }
 
   Future<void> _handleEphemerals(String id, List<dynamic> events) async {
-    for (num i = 0; i < events.length; i++) {
+    for (final event in events) {
-      await _handleEvent(events[i], id, EventUpdateType.ephemeral);
+      await _handleEvent(event, id, EventUpdateType.ephemeral);
 
       // Receipt events are deltas between two states. We will create a
       // fake room account data event for this and store the difference
       // there.
-      if (events[i]['type'] == 'm.receipt') {
+      if (event['type'] == 'm.receipt') {
         var room = getRoomById(id);
         room ??= Room(id: id);
 
         var receiptStateContent =
             room.roomAccountData['m.receipt']?.content ?? {};
-        for (var eventEntry in events[i]['content'].entries) {
+        for (var eventEntry in event['content'].entries) {
           final String eventID = eventEntry.key;
-          if (events[i]['content'][eventID]['m.read'] != null) {
+          if (event['content'][eventID]['m.read'] != null) {
             final Map<String, dynamic> userTimestampMap =
-                events[i]['content'][eventID]['m.read'];
+                event['content'][eventID]['m.read'];
             for (var userTimestampMapEntry in userTimestampMap.entries) {
               final mxid = userTimestampMapEntry.key;
 
@@ -1253,8 +1250,8 @@ class Client extends MatrixApi {
             }
           }
         }
-        events[i]['content'] = receiptStateContent;
+        event['content'] = receiptStateContent;
-        await _handleEvent(events[i], id, EventUpdateType.accountData);
+        await _handleEvent(event, id, EventUpdateType.accountData);
       }
     }
   }
@@ -1262,8 +1259,8 @@ class Client extends MatrixApi {
   Future<void> _handleRoomEvents(
       String chat_id, List<dynamic> events, EventUpdateType type,
       {bool sortAtTheEnd = false}) async {
-    for (num i = 0; i < events.length; i++) {
+    for (final event in events) {
-      await _handleEvent(events[i], chat_id, type, sortAtTheEnd: sortAtTheEnd);
+      await _handleEvent(event, chat_id, type, sortAtTheEnd: sortAtTheEnd);
     }
   }
 
@@ -1490,10 +1487,10 @@ sort order of ${prevState.sortOrder}. This should never happen...''');
 
   Future<Set<String>> _getUserIdsInEncryptedRooms() async {
     var userIds = <String>{};
-    for (var i = 0; i < rooms.length; i++) {
+    for (final room in rooms) {
-      if (rooms[i].encrypted) {
+      if (room.encrypted) {
         try {
-          var userList = await rooms[i].requestParticipants();
+          var userList = await room.requestParticipants();
           for (var user in userList) {
             if ([Membership.join, Membership.invite]
                 .contains(user.membership)) {
@@ -1872,9 +1869,9 @@ sort order of ${prevState.sortOrder}. This should never happen...''');
     if (globalPushRules == null) return false;
 
     if (globalPushRules['override'] is List) {
-      for (var i = 0; i < globalPushRules['override'].length; i++) {
+      for (final pushRule in globalPushRules['override']) {
-        if (globalPushRules['override'][i]['rule_id'] == '.m.rule.master') {
+        if (pushRule['rule_id'] == '.m.rule.master') {
-          return globalPushRules['override'][i]['enabled'];
+          return pushRule['enabled'];
         }
       }
     }

lib/src/database/database.dart

@@ -679,20 +679,12 @@ class Database extends _$Database {
 
   Future<List<sdk.User>> getUsers(int clientId, sdk.Room room) async {
     final res = await dbGetUsers(clientId, room.id).get();
-    final ret = <sdk.User>[];
+    return res.map((r) => sdk.Event.fromDb(r, room).asUser).toList();
-    for (final r in res) {
-      ret.add(sdk.Event.fromDb(r, room).asUser);
-    }
-    return ret;
   }
 
   Future<List<sdk.Event>> getEventList(int clientId, sdk.Room room) async {
     final res = await dbGetEventList(clientId, room.id).get();
-    final eventList = <sdk.Event>[];
+    return res.map((r) => sdk.Event.fromDb(r, room)).toList();
-    for (final r in res) {
-      eventList.add(sdk.Event.fromDb(r, room));
-    }
-    return eventList;
   }
 
   Future<Uint8List> getFile(String mxcUri) async {

lib/src/event.dart

@@ -274,13 +274,7 @@ class Event extends MatrixEvent {
       default:
         break;
     }
-    var toRemoveList = <String>[];
+    content.removeWhere((k, v) => !contentKeyWhiteList.contains(k));
-    for (var entry in content.entries) {
-      if (!contentKeyWhiteList.contains(entry.key)) {
-        toRemoveList.add(entry.key);
-      }
-    }
-    toRemoveList.forEach((s) => content.remove(s));
   }
 
   /// Returns the body of this event if it has a body.

lib/src/room.dart

@@ -262,13 +262,8 @@ class Room {
     }
     if (client.directChats is Map<String, dynamic>) {
       client.directChats.forEach((String userId, dynamic roomIds) {
-        if (roomIds is List<dynamic>) {
+        if (roomIds is List<dynamic> && roomIds.contains(id)) {
-          for (var i = 0; i < roomIds.length; i++) {
+          returnUserId = userId;
-            if (roomIds[i] == id) {
-              returnUserId = userId;
-              break;
-            }
-          }
         }
       });
     }
@@ -323,11 +318,7 @@ class Room {
   List<User> get typingUsers {
     if (!ephemerals.containsKey('m.typing')) return [];
     List<dynamic> typingMxid = ephemerals['m.typing'].content['user_ids'];
-    var typingUsers = <User>[];
+    return typingMxid.cast<String>().map(getUserByMXIDSync).toList();
-    for (var i = 0; i < typingMxid.length; i++) {
-      typingUsers.add(getUserByMXIDSync(typingMxid[i]));
-    }
-    return typingUsers;
   }
 
   /// Your current client instance.
@@ -384,9 +375,9 @@ class Room {
     }
     if (heroes.isNotEmpty) {
       var displayname = '';
-      for (var i = 0; i < heroes.length; i++) {
+      for (final hero in heroes) {
-        if (heroes[i].isEmpty) continue;
+        if (hero.isEmpty) continue;
-        displayname += getUserByMXIDSync(heroes[i]).calcDisplayname() + ', ';
+        displayname += getUserByMXIDSync(hero).calcDisplayname() + ', ';
       }
       return displayname.substring(0, displayname.length - 2);
     }
@@ -781,11 +772,7 @@ class Room {
 
     if (inReplyTo != null) {
       var replyText = '<${inReplyTo.senderId}> ' + inReplyTo.body;
-      var replyTextLines = replyText.split('\n');
+      replyText = replyText.split('\n').map((line) => '> $line').join('\n');
-      for (var i = 0; i < replyTextLines.length; i++) {
-        replyTextLines[i] = '> ' + replyTextLines[i];
-      }
-      replyText = replyTextLines.join('\n');
       content['format'] = 'org.matrix.custom.html';
       // be sure that we strip any previous reply fallbacks
       final replyHtml = (inReplyTo.formattedText.isNotEmpty
@@ -1465,11 +1452,9 @@ class Room {
     if (globalPushRules == null) return PushRuleState.notify;
 
     if (globalPushRules['override'] is List) {
-      for (var i = 0; i < globalPushRules['override'].length; i++) {
+      for (final pushRule in globalPushRules['override']) {
-        if (globalPushRules['override'][i]['rule_id'] == id) {
+        if (pushRule['rule_id'] == id) {
-          if (globalPushRules['override'][i]['actions']
+          if (pushRule['actions'].indexOf('dont_notify') != -1) {
-                  .indexOf('dont_notify') !=
-              -1) {
             return PushRuleState.dontNotify;
           }
           break;
@@ -1478,10 +1463,9 @@ class Room {
     }
 
     if (globalPushRules['room'] is List) {
-      for (var i = 0; i < globalPushRules['room'].length; i++) {
+      for (final pushRule in globalPushRules['room']) {
-        if (globalPushRules['room'][i]['rule_id'] == id) {
+        if (pushRule['rule_id'] == id) {
-          if (globalPushRules['room'][i]['actions'].indexOf('dont_notify') !=
+          if (pushRule['actions'].indexOf('dont_notify') != -1) {
-              -1) {
             return PushRuleState.mentionsOnly;
           }
           break;

lib/src/timeline.dart

@@ -51,8 +51,8 @@ class Timeline {
   /// found, requests from the server. Requested events
   /// are cached.
   Future<Event> getEventById(String id) async {
-    for (var i = 0; i < events.length; i++) {
+    for (final event in events) {
-      if (events[i].eventId == id) return events[i];
+      if (event.eventId == id) return event;
     }
     if (_eventCache.containsKey(id)) return _eventCache[id];
     final requestedEvent = await room.getEventById(id);