Feat: Better typing in inverter.py

examples/inverter.py

@@ -1,11 +1,19 @@
+from typing import Tuple, TypedDict
+
 from snanosm.mealy import Machine
 
+class Context(TypedDict):
+    result: str
+    n_chars: int
+
 def add_to_result(context, c):
     context["result"] += c
+    context["n_chars"] += 1
 
-def inverter(input_string: str) -> str:
-    context = {
-        "result": ""
+def inverter(input_string: str) -> Tuple[str, int]:
+    context: Context = {
+        "result": "",
+        "n_chars": 0
     }
     m = Machine(context)
     m.add_state("S", True, False)
@@ -13,7 +21,7 @@ def inverter(input_string: str) -> str:
     m.add_transition("1", "S", "S", lambda ctx: add_to_result(ctx, "0"))
     for c in input_string:
         m.process_input(c)
-    return context["result"]
+    return context["result"], context["n_chars"]
 
 if __name__ == '__main__':
     print(inverter("000011110010"))