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Rudimentary wood and pointers in rust

Based on the background of a scripting language with some C, trying to “learn”, Rust encourages me to question my competence. I am trying to figure out how to change its pointer and am trying to do this.

Besides copying from additional libs, I cannot determine the recursion that I need in the binary tree. In particular, I do not know how to replace pointer branches. If I can trick and use a temporary vector with a linked list to return a new list, or add a new Cons (value, ~ Cons) to the header, the branches hit me.

enum NaiveTreeNode {
    NNil,
    NNode(~NaiveTreeNode, ~NaiveTreeNode, int, char) 
    //         left            right          key   val
}

impl NaiveTreeNode {
  fn eq(first_node: &NaiveTreeNode, second_node: &NaiveTreeNode) -> bool {
      match (first_node, second_node) {
          (&NNil, &NNil)              => true,
          ( &NNode( ~ref left_lval, ~ref left_rval, left_leafkey, left_leafval ),
            &NNode( ~ref right_lval, ~ref right_rval, right_leafkey, right_leafval )
          ) if left_leafkey == right_leafkey && left_leafval == right_leafval => {
              NaiveTreeNode::eq(left_lval, right_lval) && NaiveTreeNode::eq(left_rval, right_rval)
          },
          _                           => false
      }
  }

  fn add_branch(&mut self, node_to_add: ~NaiveTreeNode) {
      match (self, node_to_add) {
          (&NaiveTreeNode(~NNil, ~ref r_branch, leaf_key, leaf_val), ~NaiveTreeNode(_, _, new_node_key, _)              )
              if leaf_key > new_node_key   => self = &NaiveTreeNode(node_to_add, *r_branch, leaf_key, leaf_val),
          (&NaiveTreeNode(~ref l_branch, ~NNil, leaf_key, leaf_val), ~NaiveTreeNode(_, _, new_node_key, _))
               if leaf_key < new_node_key  => self = &NaiveTreeNode(*l_branch, node_to_add, leaf_key, leaf_val),
          (&NaiveTreeNode(~ref l_branch, _, leaf_key, _), ~NaiveTreeNode(_, _, new_node_key, _)) 
               if leaf_key > new_node_key  => self.add_branch(l_branch, node_to_add),
          (&NaiveTreeNode(_, ~ref r_branch, leaf_key, _), ~NaiveTreeNode(_, _, new_node_key, _)) 
               if leaf_key < new_node_key  => self.add_branch(l_branch, node_to_add),
          (_, ~NNil)                       => fail!("NNil branch. failing"),
          (&NNil, _)                       => fail!("NNil trunk. failing"),
          _                                => fail!("something is wrong. failing.")
      };
  }
}

11 errors are thrown in this compiler, and when I print it, it looks like a pseudo-code. I am upset because I feel good implementing the tree with pointers to C.

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, , . Treemap, , , , , - , , !

+3
1

, :

struct NaiveTreeNode {
    left: Option<~NaiveTreeNode>,
    right: Option<~NaiveTreeNode>,
    key: int,
    val: char,
}

(Option<~T> , node, , , NNil).

eq; , eq, #[deriving(Eq)] .

add_branch , self.add_branch - , self. self.add_branch(l_branch, node_to_add), , . l_branch.add_branch(node_to_add).

add_branch; , :

#[deriving(Eq)]
struct NaiveTreeNode {
    left: Option<~NaiveTreeNode>,
    right: Option<~NaiveTreeNode>,
    key: int,
    val: char,
}

impl NaiveTreeNode {
    fn add_branch(&mut self, node: ~NaiveTreeNode) {
        match (self.key.cmp(node.key), self.left, self.right) {
            (Greater, None, _) => self.left = Some(node),
            (Greater, Some(~ref mut left), _) => left.add_branch(node),
            (Less, _, None) => self.right = Some(node),
            (Less, _, Some(~ref mut right)) => right.add_branch(node),
            (Equal, _, _) => fail!("this tree already has a node with key {} \
                                    (value {}, attempted value {})", 
                                   self.key, self.value, node.value),
        }
    }
}

:

        match self.key.cmp(node.key) {
            Greater => match self.left {
                None => self.left = Some(node),
                Some(~ref mut left) => left.add_branch(node),
            },
            Less => match self.right {
                None => self.right = Some(node),
                Some(~ref mut right) => right.add_branch(node),
            },
            Equal => fail!("this tree already has a node with key {} \
                                  (value {}, attempted value {})", 
                                  self.key, self.value, node.value),
        }

-, , , .

+5

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