T7321: move load_config util from vyconf for general use

2 files changed, 35 insertions, 0 deletions

diff --git a/src/config_file.ml b/src/config_file.ml
new file mode 100644
index 0000000..5fdf924
--- /dev/null
+++ b/src/config_file.ml
@@ -0,0 +1,33 @@
+(* strip commponent version string *)
+let strip_version s =
+    let rex = Pcre.regexp ~flags:[`MULTILINE;`DOTALL] "(^//.*)" in
+    let res = Pcre.split ~max:0 ~rex s in
+    match res with
+    | h :: _ -> Ok h
+    | [] -> Error "Failure stripping version string from config"
+
+let load_config file =
+    try
+        let chan = open_in file in
+        let s = really_input_string chan (in_channel_length chan) in
+        let () = close_in chan in
+        let prep = strip_version s in
+        let s = match prep with
+            | Ok s -> s
+            | Error msg -> raise (Sys_error msg)
+        in
+        let config = Parser.from_string s in
+        Ok config
+    with
+        | Sys_error msg -> Error msg
+        | Util.Syntax_error (opt, msg) ->
+            begin
+                match opt with
+                | None ->
+                    let out = Printf.sprintf "Parse error: %s\n" msg
+                    in Error out
+                | Some (line, pos) ->
+                    let out = Printf.sprintf "Parse error: %s line %d pos %d\n" msg line pos
+                    in Error out
+            end
+
diff --git a/src/config_file.mli b/src/config_file.mli
new file mode 100644
index 0000000..607a8b5
--- /dev/null
+++ b/src/config_file.mli
@@ -0,0 +1,2 @@
+
+val load_config : string -> (Config_tree.t, string) result