Improved Bit class

lib/src/bit.dart

@@ -2,35 +2,43 @@ import 'dart:typed_data';
 import 'utils.dart';
 
 class Bit {
-  final List<bool> _vec;
+  final int _len;
+  final Uint8List _data;
 
-  const Bit(this._vec);
+  const Bit._(this._len, this._data);
 
-  factory Bit.fromBinary(Uint8List bytes) {
-    var buf = new ByteData.view(bytes.buffer, bytes.offsetInBytes);
-    var length = buf.getInt32(0);
-
-    var vec = <bool>[];
+  factory Bit(List<bool> value) {
+    var length = value.length;
+    var data = Uint8List(((length + 7) / 8).toInt());
     for (var i = 0; i < length; i++) {
-      vec.add((bytes[4 + (i / 8).toInt()] >> (7 - (i % 8))) & 1 == 1);
+      data[(i / 8).toInt()] |= (value[i] ? 1 : 0) << (7 - (i % 8));
     }
+    return Bit._(length, data);
+  }
 
-    return Bit(vec);
+  factory Bit.fromBinary(Uint8List bytes) {
+    var buf = new ByteData.view(bytes.buffer, bytes.offsetInBytes);
+    var length = buf.getInt32(0);
+    return Bit._(length, bytes.sublist(4));
   }
 
   List<bool> toList() {
-    return _vec;
+    var vec = <bool>[];
+    for (var i = 0; i < _len; i++) {
+      vec.add((_data[(i / 8).toInt()] >> (7 - (i % 8))) & 1 == 1);
+    }
+    return vec;
   }
 
   @override
   String toString() {
-    return _vec.map((v) => v ? '1' : '0').join();
+    return toList().map((v) => v ? '1' : '0').join();
   }
 
   @override
   bool operator ==(Object other) =>
-      other is Bit && listEquals(other._vec, _vec);
+      other is Bit && other._len == _len && listEquals(other._data, _data);
 
   @override
-  int get hashCode => _vec.hashCode;
+  int get hashCode => Object.hash(_len, _data);
 }