JMatchJava模式匹配库

示例代码：

static RBNode balance(int color, int value, RBTree left, RBTree right)

{

  if (color == BLACK) {

    switch (value,left,right) {

      case int z,

           RBNode(RED,int y,RBNode(RED,int x,RBTree a,RBTree b),RBTree c),

           RBTree d:

      case z, RBNode(RED,x,a,RBNode(RED,y,b,c)),d:

      case x, a, RBNode(RED,z,RBNode(RED,y,b,c),d):

      case x, a, RBNode(RED,y,b,RBNode(RED,z,c,d)):

        return RBNode(RED,y,RBNode(BLACK,x,a,b),RBNode(BLACK,z,c,d));

    }

  }

  return RBNode(color, value, left, right);

}