Add recipe for approximating dynamic fields of heterogeneous types like in Python

dynamic_approximating_dynamic_types.nim

@@ -0,0 +1,38 @@
+# Context
+# https://forum.nim-lang.org/t/5000#31345
+#
+# The goal is to approximate the dynamic creation of properties
+# we use Nim dot operators for that and store everything in a Json object.
+
+import json
+
+{.experimental: "dotOperators".}
+
+type
+  Action = ref object
+    properties: JsonNode
+
+template `.`(action: Action, field: untyped): untyped =
+  action.properties[astToStr(field)]
+
+template `.=`(action: Action, field, value: untyped): untyped =
+  action.properties[astToStr(field)] = %value
+
+
+# Our main object, the fields are dynamic
+
+var a = Action(
+  properties: %*{
+    "layer": 0,
+    "add": true,
+    "vis": false,
+    "new_name": "fancy_name"
+  }
+)
+
+# And usage, those are not real fields but there is no difference in syntax
+
+echo a.new_name # "fancy_name"
+
+a.algo = 10
+echo a.algo     # 10