lib: Add missing __repr__ to common

lib/common.py

@@ -47,6 +47,9 @@ class Character:
     def __hash__(self):
         return hash(self.name)
 
+    def __repr__(self) -> str:
+        return f"Character({self.name})"
+
 
 class State:
     def __init__(self, name: str):
@@ -83,6 +86,9 @@ class Eps:
     def __len__(self):
         return 0
 
+    def __repr__(self) -> str:
+        return "Eps()"
+
 
 class Emptyset:
     def __init__(self):
@@ -93,3 +99,6 @@ class Emptyset:
 
     def __hash__(self):
         return hash("∅")
+
+    def __repr__(self) -> str:
+        return "Emptyset()"