First acceptable solution

Project-02-03-04/cfg/CFG_Node.py

@@ -5,7 +5,10 @@ class CFG_Node:
         self.ast_node = ast_node
         self.children = set()
         self.parents = set()
-        self.label = None  # Optional label for the node
+
+        self.label = None
+        self.dot_shape = 'box'
+        self.dot_style = ''
         
         self.id = CFG_Node.__counter
         CFG_Node.__counter += 1
@@ -36,44 +39,58 @@ class CFG_Node:
             parent.children.remove(self)
         self.parents.remove(parent)
 
-    def __str__(self):
-        if self.label:
-            return f"CFG_Node({self.id}, label='{self.label}')"
-        elif self.ast_node:
-            return f"CFG_Node({self.id}, ast={type(self.ast_node).__name__})"
-        else:
-            return f"CFG_Node({self.id})"
+    def dot_label(self):
+        # Prioritize custom label
+        if self.label is not None:
+            return self.label
 
-    def __repr__(self):
-        return self.__str__()
+        # Build label from AST node
+        if self.ast_node is not None:
+            return str(self.ast_node)
 
+        return None
+
+    def is_filled(self):
+        return not self.is_empty()
+
+    def is_empty(self):
+        # Node is empty if it has no label and no related AST node
+        if self.label is None or self.label == "None":
+            if self.ast_node is not None:
+                # Node belongs to a ast node
+                return False
+            return True
+        # Node is required for the control flow
+        return False
 
 class CFG_START(CFG_Node):
-    def dot_shape(self):
-        return "box"
-
-    def dot_label(self):
-        return "START"
-
+    def __init__(self, ast_node=None):
+        super().__init__(ast_node)
+        self.dot_shape = "ellipse"
+        self.dot_style = 'style=filled, color=green'
+        self.label = "START"
 
 class CFG_END(CFG_Node):
-    def dot_shape(self):
-        return "box"
-
-    def dot_label(self):
-        return "END"
-
+    def __init__(self, ast_node=None):
+        super().__init__(ast_node)
+        self.dot_shape = "ellipse"
+        self.dot_style = 'style=filled, color=green'
+        self.label = "END"
 
 class CFG_DIAMOND(CFG_Node):
-    def dot_shape(self):
-        return "diamond"
-
+    def __init__(self, ast_node=None):
+        super().__init__(ast_node)
+        self.dot_shape = "diamond"
+        self.label = "<?>"
 
 class CFG_CALL(CFG_Node):
-    def dot_shape(self):
-        return "box"
-
+    def __init__(self, ast_node=None):
+        super().__init__(ast_node)
+        self.dot_style = 'style=filled, color=orange'
+        self.dot_shape = "box"
 
 class CFG_RETURN(CFG_Node):
-    def dot_shape(self):
-        return "box"
+    def __init__(self, ast_node=None):
+        super().__init__(ast_node)
+        self.dot_style = 'style=filled, color=orange'
+        self.dot_shape = "box"