dart_mixin.dart

dart_mixin.dart

import 'dart:math' as math;

class Point {
  final int x;
  final int y;
  const Point(this.x, this.y);
}

// class / abstract class can be used as mixin
class LastPoint {
  bool last = false;
}

// Mixin depends on class
mixin Distance on Point {
  double distance(Point p) {
    final a = (x - p.x).abs();
    final b = (y - p.y).abs();
    return math.sqrt(a*a + b*b);
  }
}

class PointWithDistance extends Point with Distance, LastPoint {
  PointWithDistance(int x, int y) : super(x, y);
}


void main() {
  final p1 = PointWithDistance(0, 3);
  final p2 = PointWithDistance(4, 0)
      ..last = true;
  final distance = p1.distance(p2);
  print(distance);
}