Finish implementing GameTree.Clone and PartialEq

sgf/src/game.rs

@@ -5,7 +5,9 @@ use crate::{
 use serde::{Deserialize, Serialize};
 use slab_tree::{NodeId, NodeMut, NodeRef, Tree};
 use std::{
-    collections::{HashSet, VecDeque},
+    collections::{HashMap, HashSet, VecDeque},
+    fmt::Debug,
+    ops::Deref,
     time::Duration,
 };
 use uuid::Uuid;
@@ -56,6 +58,7 @@ pub struct Player {
 /// syntax issues, the result of the GameRecord is to have a fully-understood game. However, this
 /// doesn't (yet?) go quite to the level of apply the game type (i.e., this is Go, Chess, Yinsh, or
 /// whatever).
+#[derive(Clone, Debug, PartialEq)]
 pub struct GameRecord {
     pub game_type: GameType,
 
@@ -81,7 +84,7 @@ pub struct GameRecord {
     pub overtime: Option<String>,
     pub transcriber: Option<String>,
 
-    pub trees: Vec<Tree<GameNode>>,
+    pub trees: Vec<GameTree>,
 }
 
 impl GameRecord {
@@ -134,7 +137,7 @@ impl GameRecord {
     /// children.
     pub fn mainline(&self) -> Option<impl Iterator<Item = &'_ GameNode>> {
         println!("number of trees: {}", self.trees.len());
-        if self.trees.len() > 0 {
+        if !self.trees.is_empty(){
             Some(MainlineIter {
                 next: self.trees[0].root(),
                 tree: &self.trees[0],
@@ -233,15 +236,18 @@ impl TryFrom<parser::Tree> for GameRecord {
             .map_err(GameError::InvalidGameNode)?;
             */
 
-        s.trees = tree.root.next.into_iter()
+        s.trees = tree
+            .root
+            .next
+            .into_iter()
             .map(recursive_tree_to_slab_tree)
-            .collect::<Result<Vec<Tree<GameNode>>, GameError>>()?;
+            .collect::<Result<Vec<GameTree>, GameError>>()?;
 
         Ok(s)
     }
 }
 
-fn recursive_tree_to_slab_tree(node: parser::Node) -> Result<Tree<GameNode>, GameError> {
+fn recursive_tree_to_slab_tree(node: parser::Node) -> Result<GameTree, GameError> {
     let mut slab = Tree::new();
     let mut nodes: VecDeque<(NodeId, parser::Node)> = VecDeque::new();
 
@@ -269,13 +275,15 @@ fn recursive_tree_to_slab_tree(node: parser::Node) -> Result<Tree<GameNode>, Gam
         }
     }
 
-    Ok(slab)
+    Ok(GameTree(slab))
 }
 
+#[derive(Default)]
 pub struct TreeIter<'a> {
     queue: VecDeque<NodeRef<'a, &'a GameNode>>,
 }
 
+/*
 impl<'a> Default for TreeIter<'a> {
     fn default() -> Self {
         TreeIter {
@@ -283,6 +291,7 @@ impl<'a> Default for TreeIter<'a> {
         }
     }
 }
+*/
 
 impl<'a> Iterator for TreeIter<'a> {
     type Item = &'a GameNode;
@@ -298,6 +307,86 @@ impl<'a> Iterator for TreeIter<'a> {
     }
 }
 
+pub struct GameTree(Tree<GameNode>);
+
+impl Clone for GameTree {
+    fn clone(&self) -> Self {
+        match self.0.root() {
+            None => Self(Tree::new()),
+            Some(source_root_node) => {
+                let mut dest = Tree::new();
+                let dest_root_id = dest.set_root(source_root_node.data().clone());
+
+                // In order to add a node to the new tree, I need to know the ID of the parent in
+                // the source tree and the ID of the parent in the destination tree. So I want a
+                // lookup table that maps source IDs to destination IDs. But is that sufficient?
+                // Perhaps I can just keep a mapping from a source noderef to a destination ID.
+                // I don't think I can keep more than one mutable destination node.
+
+                let mut mapping: HashMap<NodeId, NodeId> = HashMap::new();
+                mapping.insert(source_root_node.node_id(), dest_root_id);
+
+                for source_node in source_root_node.traverse_level_order() {
+                    match source_node.parent() {
+                        None => {}
+                        Some(parent) => {
+                            let source_node_parent_id = parent.node_id();
+                            let target_node_parent_id = mapping.get(&source_node_parent_id).expect("node should have been added to the source to dest mapping when being cloned");
+
+                            let mut parent = dest.get_mut(*target_node_parent_id).expect(
+                        "destination parent node to exist before reaching potential children",
+                    );
+                            let dest_id = parent.append(source_node.data().clone()).node_id();
+                            mapping.insert(source_node.node_id(), dest_id);
+                        }
+                    }
+                }
+
+                Self(dest)
+            }
+        }
+    }
+}
+
+impl Debug for GameTree {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        self.write_formatted(f)
+    }
+}
+
+impl Deref for GameTree {
+    type Target = Tree<GameNode>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl PartialEq for GameTree {
+    fn eq(&self, other: &Self) -> bool {
+        // Get pre-order iterators over both trees, zip them, and ensure that the data contents are
+        // the same between them
+        let left_root = self.root();
+        let right_root = other.root();
+
+        match (left_root, right_root) {
+            (Some(left_root), Some(right_root)) => {
+                for (left_node, right_node) in std::iter::zip(
+                    left_root.traverse_pre_order(),
+                    right_root.traverse_pre_order(),
+                ) {
+                    if left_node.data() != right_node.data() {
+                        return false;
+                    }
+                }
+            }
+            (None, None) => return true,
+            _ => return false,
+        }
+        true
+    }
+}
+
 pub struct MainlineIter<'a> {
     next: Option<NodeRef<'a, GameNode>>,
     tree: &'a Tree<GameNode>,
@@ -338,33 +427,12 @@ impl TryFrom<parser::Node> for GameNode {
     type Error = GameNodeError;
 
     fn try_from(n: parser::Node) -> Result<Self, Self::Error> {
-        // I originally wrote this recursively. However, on an ordinary game of a couple hundred
-        // moves, that meant that I was recursing 500 functions, and that exceeded the stack limit.
-        // So, instead, I need to unroll everything to non-recursive form.
-        //
-        // So, I can treat each branch of the tree as a single line. Iterate over that line. I can
-        // only use the MoveNode::try_from and SetupNode::try_from if those functions don't
-        // recurse. Instead, I'm going to process just that node, then return to here and process
-        // the children.
         let move_node = MoveNode::try_from(n.clone());
         let setup_node = SetupNode::try_from(n.clone());
 
-        // I'm much too tired when writing this. I'm still recursing, but I did cut the number of
-        // recursions in half. This helps, but it still doesn't guarantee that I'm going to be able
-        // to parse all possible games. So, still, treat each branch of the game as a single line.
-        // Iterate over that line, don't recurse. Create bookmarks at each branch point, and then
-        // come back to each one.
-        /*
-        let children = n
-            .next
-            .iter()
-            .map(GameNode::try_from)
-            .collect::<Result<Vec<Self>, Self::Error>>()?;
-            */
-
         match (move_node, setup_node) {
-            (Ok(mut node), _) => Ok(Self::MoveNode(node)),
-            (Err(_), Ok(mut node)) => Ok(Self::SetupNode(node)),
+            (Ok(node), _) => Ok(Self::MoveNode(node)),
+            (Err(_), Ok(node)) => Ok(Self::SetupNode(node)),
             (Err(move_err), Err(setup_err)) => {
                 Err(Self::Error::UnsupportedGameNode(move_err, setup_err, n))
             }
@@ -950,4 +1018,14 @@ mod file_test {
             });
         });
     }
+
+    #[test]
+    fn it_can_copy_a_game_record() {
+        with_file(std::path::Path::new("test_data/multi-tree.sgf"), |games| {
+            let dest = games.clone();
+
+            assert_eq!(games.len(), dest.len());
+            assert_eq!(games[0], dest[0]);
+        });
+    }
 }

sgf/src/lib.rs

@@ -22,6 +22,7 @@ pub enum Error {
     InvalidSgf(VerboseNomError),
 }
 
+#[allow(dead_code)]
 #[derive(Debug)]
 pub struct VerboseNomError(nom::error::VerboseError<String>);
 
@@ -73,7 +74,7 @@ pub fn parse_sgf(input: &str) -> Result<Vec<Result<GameRecord, game::GameError>>
     let (_, games) = parse_collection::<nom::error::VerboseError<&str>>(input)?;
     let games = games
         .into_iter()
-        .map(|game| GameRecord::try_from(game))
+        .map(GameRecord::try_from)
         .collect::<Vec<Result<GameRecord, game::GameError>>>();
 
     Ok(games)

sgf/src/types.rs

@@ -56,6 +56,7 @@ pub enum Error {
     InvalidSgf(VerboseNomError),
 }
 
+#[allow(dead_code)]
 #[derive(Debug)]
 pub struct VerboseNomError(nom::error::VerboseError<String>);