Initial AP objects implementation

source/util.d

@@ -0,0 +1,20 @@
+module util;
+
+import std.format;
+import std.json;
+
+JSONValue requiredKey(string key)(JSONValue val) {
+  const(JSONValue)* j = key in val;
+
+  if (j)
+    return *j;
+
+  throw new Exception(format("Key %s not found in json", key));
+}
+
+T checkKey(T)(JSONValue val, string key) {
+  if (JSONValue* j = key in val)
+    return (*j).get!T;
+
+  return T.init;
+}