1 files changed, 29 insertions, 0 deletions
diff --git a/lib/concepts/Condition.ml b/lib/concepts/Condition.ml
new file mode 100644
index 0000000..cc0f7a7
--- /dev/null
+++ b/lib/concepts/Condition.ml
@@ -0,0 +1,29 @@
+type properties = (string, Value.value) BatMap.t
+type ps = properties -> properties
+
+type condition =
+  {name: string; message: string; backtrace: Printexc.raw_backtrace; properties: properties}
+
+let ( |=| ) name value = fun p -> BatMap.add name value p
+let ( & ) l r = fun p -> r (l p)
+let empty = fun p -> p
+
+let condition name message ?parent props =
+  { name;
+    message;
+    backtrace= Printexc.get_callstack 256;
+    properties=
+      parent
+      |> Option.map (fun {properties; _} -> properties)
+      |> Option.value ~default:BatMap.empty
+      |> props }
+
+let to_string_hum {name; message; properties; backtrace} =
+  let properties' =
+    properties
+    |> BatMap.to_seq
+    |> BatSeq.to_string ~first:"" ~last:"" ~sep:"\n" (fun (k, v) ->
+        "\t" ^ k ^ ": " ^ Value.to_string v )
+  in
+  let backtrace' = Printexc.raw_backtrace_to_string backtrace in
+  name ^ ": " ^ message ^ "\n" ^ properties' ^ "\n\nBacktrace:\n" ^ backtrace'