1 files changed, 45 insertions, 6 deletions

diff --git a/src/curly_parser.mly b/src/curly_parser.mly
index 58c6067..7daa082 100644
--- a/src/curly_parser.mly
+++ b/src/curly_parser.mly
@@ -1,5 +1,25 @@
 %{
     open Config_tree
+
+    exception Duplicate_child of (string * string)
+
+    (* Used for checking if after merging immediate children,
+       any of them have duplicate children inside,
+       e.g. "interfaces { ethernet eth0 {...} ethernet eth0 {...} }" *)
+    let find_duplicate_children n =
+        let rec aux xs =
+            let xs = List.sort compare xs in
+            match xs with
+            | [] | [_] -> ()
+            | x :: x' :: xs ->
+                if x = x' then raise (Duplicate_child (Vytree.name_of_node n, x))
+                else aux (x' :: xs)
+        in
+        aux @@ Vytree.list_children n
+
+    (* When merging nodes with values, append values of subsequent nodes to the
+       first one *)
+    let merge_data l r = {l with values=(List.append l.values r.values)}
 %}
 
 %token <string> IDENTIFIER
@@ -43,7 +63,13 @@ node:
   | comment = opt_comment; name = IDENTIFIER; LEFT_BRACE; children = list(node_content); RIGHT_BRACE
     {
         let node = Vytree.make_full {default_data with comment=comment} name [] in
-        List.fold_left Vytree.adopt node (List.rev children) |> Vytree.merge_children
+        let node = List.fold_left Vytree.adopt node (List.rev children) |> Vytree.merge_children merge_data in
+        try
+            List.iter find_duplicate_children (Vytree.children_of_node node);
+            node
+        with
+        | Duplicate_child (child, dup) ->
+            failwith (Printf.sprintf "Node \"%s %s\" has two children named \"%s\"" name child dup)
     }
 ;
 
@@ -52,15 +78,28 @@ tag_node:
   {
       let outer_node = Vytree.make_full default_data name [] in
       let inner_node = Vytree.make_full {default_data with comment=comment} tag [] in
-      let inner_node = List.fold_left Vytree.adopt inner_node (List.rev children) |> Vytree.merge_children
-      in Vytree.adopt outer_node inner_node
+      let inner_node = List.fold_left Vytree.adopt inner_node (List.rev children) |> Vytree.merge_children merge_data in
+      let node = Vytree.adopt outer_node inner_node in
+      try
+          List.iter find_duplicate_children (Vytree.children_of_node inner_node);
+          node
+      with
+      | Duplicate_child (child, dup) ->
+          failwith (Printf.sprintf "Node \"%s %s %s\" has two children named \"%s\"" name tag child dup)
   }
 
 node_content: n = node { n } | n = leaf_node { n } | n = tag_node { n };
 
 %public config:
-    ns = list(node);  EOF
-  {
-    let root = make "root" in List.fold_left Vytree.adopt root (List.rev ns) |> Vytree.merge_children
+ | ns = list(node);  EOF
+ {
+    let root = make "root" in
+    let root = List.fold_left Vytree.adopt root (List.rev ns) |> Vytree.merge_children merge_data in
+        try
+            List.iter find_duplicate_children (Vytree.children_of_node root);
+            root
+        with
+        | Duplicate_child (child, dup) ->
+            failwith (Printf.sprintf "Node \"%s\" has two children named \"%s\"" child dup)
   }
 ;