Merge pull request #3 from jestabro/subtree

T4235: simplify return value of diff_tree

4 files changed, 34 insertions, 6 deletions

diff --git a/src/config_diff.ml b/src/config_diff.ml
index 75d12dd..565d64f 100644
--- a/src/config_diff.ml
+++ b/src/config_diff.ml
@@ -15,7 +15,7 @@ exception Empty_comparison
 
 module ValueS = Set.Make(struct type t = string let compare = compare end)
 
-let make_diff_tree l r = { left = l; right = r;
+let make_diff_trees l r = { left = l; right = r;
                            add = ref (Config_tree.make "root");
                            del = ref (Config_tree.make "root");
                            inter = ref (Config_tree.make "root");
@@ -109,6 +109,16 @@ let clone ?(with_children=true) ?(set_values=[]) old_root new_root path =
             let path_remaining = Vylist.complement path path_existing in
             clone_path ~with_children:with_children ~set_values:set_values old_root new_root path_existing path_remaining
 
+let rec graft_children children stock path =
+    match children with
+    | [] -> stock
+    | x::xs ->
+            let stock = Vytree.insert ~children:(children_of x) stock (path @ [name_of x]) (data_of x)
+            in graft_children xs stock path
+
+let graft_tree stem stock path =
+    graft_children (children_of stem) stock path
+
 (* define the diff_func; in this instance, we imperatively build the difference trees *)
 let decorate_trees (trees : diff_trees) ?(with_children=true) (path : string list) (m : change) =
     match m with
@@ -147,11 +157,18 @@ let compare path left right =
     else
         let (left, right) = if not (path = []) then
             (tree_at_path path left, tree_at_path path right) else (left, right) in
-        let trees = make_diff_tree left right in
+        let trees = make_diff_trees left right in
         diff [] (decorate_trees trees) [(Option.some left, Option.some right)];
         trees
 
 (* wrapper to return diff trees *)
-let diffs path left right =
+let diff_tree path left right =
     let trees = compare path left right in
-    (!(trees.add), !(trees.del), !(trees.inter))
+    let add_node = Config_tree.make "add" in
+    let del_node = Config_tree.make "delete" in
+    let int_node = Config_tree.make "inter" in
+    let ret = make Config_tree.default_data "root" [add_node; del_node; int_node] in
+    let ret = graft_tree !(trees.add) ret ["add"] in
+    let ret = graft_tree !(trees.del) ret ["delete"] in
+    let ret = graft_tree !(trees.inter) ret ["inter"] in
+    ret
diff --git a/src/config_diff.mli b/src/config_diff.mli
index 623c6ef..5f96209 100644
--- a/src/config_diff.mli
+++ b/src/config_diff.mli
@@ -13,9 +13,9 @@ type diff_trees = {
 exception Incommensurable
 exception Empty_comparison
 
-val make_diff_tree : Config_tree.t -> Config_tree.t -> diff_trees
+val make_diff_trees : Config_tree.t -> Config_tree.t -> diff_trees
 val clone : ?with_children:bool -> ?set_values:string list -> Config_tree.t -> Config_tree.t -> string list -> Config_tree.t
 val decorate_trees : diff_trees -> ?with_children:bool -> string list -> change -> unit
 val compare : string list -> Config_tree.t -> Config_tree.t -> diff_trees
-val diffs : string list -> Config_tree.t -> Config_tree.t -> Config_tree.t * Config_tree.t * Config_tree.t
+val diff_tree : string list -> Config_tree.t -> Config_tree.t -> Config_tree.t
 
diff --git a/src/config_tree.ml b/src/config_tree.ml
index 6ae7ad2..3e97e80 100644
--- a/src/config_tree.ml
+++ b/src/config_tree.ml
@@ -101,6 +101,15 @@ let is_tag node path =
     let data = Vytree.get_data node path in
     data.tag
 
+let get_subtree ?(with_node=false) node path =
+    try
+        let n = Vytree.get node path in
+        if with_node then
+            Vytree.make_full default_data "root" [n]
+        else
+            Vytree.make_full default_data "root" (Vytree.children_of_node n)
+    with Vytree.Nonexistent_path -> make "root"
+
 module Renderer =
 struct
     (* Rendering configs as set commands *)
diff --git a/src/config_tree.mli b/src/config_tree.mli
index cf94af7..5375c23 100644
--- a/src/config_tree.mli
+++ b/src/config_tree.mli
@@ -34,6 +34,8 @@ val set_tag : t -> string list -> bool -> t
 
 val is_tag : t -> string list -> bool
 
+val get_subtree : ?with_node:bool -> t -> string list -> t
+
 val render_commands : ?op:command -> t -> string list -> string
 
 val render_config : t -> string