feat(xml): add function element_to_string

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/xml.ml b/lib/xml.ml
index 1b286bb..f568a0f 100644
--- a/lib/xml.ml
+++ b/lib/xml.ml
@@ -26,3 +26,29 @@ let tree s : element option =
   and text ss = Either.Right (String.concat "" ss) in
   let opt_el = tree ~text ~element s in
   Option.bind opt_el (Either.fold ~left:Option.some ~right:(fun _ -> None))
+
+let element_to_string ?(indent = 2) (el : element) =
+  (** [element_to_string element] is a string representation of the underlying XML in
+      [element], for debugging purposes.
+
+      Note this isn't serialization: namely, XML namespaces are ignored. *)
+  let rec element_to_string {local_name; attributes; children; _} =
+    let attributes =
+      String.concat ""
+        (List.map (fun (n, a) -> " " ^ n ^ "=\"" ^ a ^ "\"") attributes)
+    in
+    let tab s =
+      String.split_on_char '\n' s |> String.concat ("\n" ^ String.make indent ' ')
+    in
+    let tag = "\n<" ^ local_name ^ attributes
+    in tag ^ match children with
+             | [] -> "/>"
+             | _ -> ">" ^ (children
+                           |> List.map
+                                (Either.fold
+                                   ~left:element_to_string
+                                   ~right:(fun x -> "\n" ^ x))
+                           |> String.concat ""
+                           |> tab)
+                    ^ "\n</" ^ local_name ^ ">"
+  in element_to_string el |> String.trim