Restructure nyxx_extensions (#31)

lib/nyxx_extensions.dart

@@ -1,15 +1,30 @@
+/// Extensions and additional utilities for working with [nyxx](https://pub.dev/packages/nyxx).
 library nyxx_extensions;
 
-export 'src/channel.dart';
-export 'src/date_time.dart';
-export 'src/embed_builder.dart';
-export 'src/emoji.dart';
-export 'src/guild.dart';
-export 'src/message.dart';
-export 'src/pagination.dart';
-export 'src/role.dart';
-export 'src/sanitizer.dart';
-export 'src/user.dart';
+export 'src/utils/emoji.dart';
+export 'src/utils/endpoint_paginator.dart' hide streamPaginatedEndpoint;
 export 'src/utils/formatters.dart';
-export 'src/permissions.dart';
-export 'src/endpoint_paginator.dart';
+export 'src/utils/pagination.dart';
+export 'src/utils/permissions.dart';
+export 'src/utils/sanitizer.dart';
+
+export 'src/extensions/channel.dart';
+export 'src/extensions/client.dart';
+export 'src/extensions/date_time.dart';
+export 'src/extensions/embed.dart';
+export 'src/extensions/emoji.dart';
+export 'src/extensions/guild.dart';
+export 'src/extensions/managers/audit_log_manager.dart';
+export 'src/extensions/managers/channel_manager.dart';
+export 'src/extensions/managers/entitlement_manager.dart';
+export 'src/extensions/managers/guild_manager.dart';
+export 'src/extensions/managers/member_manager.dart';
+export 'src/extensions/managers/message_manager.dart';
+export 'src/extensions/managers/scheduled_event_manager.dart';
+export 'src/extensions/managers/user_manager.dart';
+export 'src/extensions/member.dart';
+export 'src/extensions/message.dart';
+export 'src/extensions/role.dart';
+export 'src/extensions/scheduled_event.dart';
+export 'src/extensions/snowflake_entity.dart';
+export 'src/extensions/user.dart';

lib/src/extensions/channel.dart

@@ -0,0 +1,33 @@
+import 'package:nyxx/nyxx.dart';
+import 'package:nyxx_extensions/src/extensions/managers/channel_manager.dart';
+import 'package:nyxx_extensions/src/utils/formatters.dart';
+import 'package:nyxx_extensions/src/utils/permissions.dart';
+
+/// Extensions on [PartialChannel]s.
+extension PartialChannelExtensions on PartialChannel {
+  /// A mention of this channel.
+  String get mention => channelMention(id);
+}
+
+/// Extensions on [Channel]s.
+extension ChannelExtensions on Channel {
+  /// A URL clients can visit to navigate to this channel.
+  Uri get url => Uri.https(manager.client.apiOptions.host, '/channels/${this is GuildChannel ? '${(this as GuildChannel).guildId}' : '@me'}/$id');
+}
+
+/// Extensions on [GuildChannel]s.
+extension GuildChannelExtensions on GuildChannel {
+  /// Compute [member]'s permissions in this channel.
+  ///
+  /// {@macro compute_permissions_detail}
+  Future<Permissions> computePermissionsFor(PartialMember member) async => await computePermissions(this, await member.get());
+}
+
+/// Extensions on [Thread]s.
+extension ThreadExtensions on Thread {
+  /// Same as [listThreadMembers], but has no limit on the number of members returned.
+  ///
+  /// {@macro paginated_endpoint_streaming_parameters}
+  Stream<ThreadMember> streamThreadMembers({bool? withMembers, Snowflake? after, Snowflake? before, int? pageSize}) =>
+      manager.streamThreadMembers(id, withMembers: withMembers, after: after, before: before, pageSize: pageSize);
+}