Throw basis of LeafTree

mapytex/calculus/core/tree.py

@@ -311,48 +311,6 @@ class Tree(object):
 
         return function(self.node, left_value, right_value)
 
-    def to_nested_parenthesis(self):
-        """ Transform the Tree into its nested parenthesis description
-        :example:
-
-        >>> nested_par = ("+", (1, 2))
-        >>> t = Tree.from_nested_parenthesis(nested_par)
-        >>> t.to_nested_parenthesis()
-        ('+', (1, 2))
-        >>> nested_par = ("+", (
-        ...    ("*", (3, 4)),
-        ...    2))
-        >>> t = Tree.from_nested_parenthesis(nested_par)
-        >>> t.to_nested_parenthesis()
-        ('+', (('*', (3, 4)), 2))
-        """
-        return self.apply(to_nested_parenthesis)
-
-    def to_postfix(self):
-        """ Transform the Tree into postfix notation
-
-        :example:
-
-        >>> nested_par = ("+", (1, 2))
-        >>> t = Tree.from_nested_parenthesis(nested_par)
-        >>> t.to_postfix()
-        [1, 2, '+']
-        >>> nested_par = ("+", (
-        ...    ("*", (3, 4)),
-        ...    2))
-        >>> t = Tree.from_nested_parenthesis(nested_par)
-        >>> t.to_postfix()
-        [3, 4, '*', 2, '+']
-        >>> nested_par = ("+", (
-        ...    ("*", (3, 4)),
-        ...    ("*", (5, 6)),
-        ...     ))
-        >>> t = Tree.from_nested_parenthesis(nested_par)
-        >>> t.to_postfix()
-        [3, 4, '*', 5, 6, '*', '+']
-        """
-        return self.apply(postfix_concatenate)
-
     def get_leafs(self, callback = lambda x:x):
         """ Generator which yield all the leaf value of the tree.
         Callback act on every leaf.
@@ -475,6 +433,49 @@ class Tree(object):
         """
         return self.apply(show_tree)
 
+    def to_nested_parenthesis(self):
+        """ Transform the Tree into its nested parenthesis description
+        :example:
+
+        >>> nested_par = ("+", (1, 2))
+        >>> t = Tree.from_nested_parenthesis(nested_par)
+        >>> t.to_nested_parenthesis()
+        ('+', (1, 2))
+        >>> nested_par = ("+", (
+        ...    ("*", (3, 4)),
+        ...    2))
+        >>> t = Tree.from_nested_parenthesis(nested_par)
+        >>> t.to_nested_parenthesis()
+        ('+', (('*', (3, 4)), 2))
+        """
+        return self.apply(to_nested_parenthesis)
+
+    def to_postfix(self):
+        """ Transform the Tree into postfix notation
+
+        :example:
+
+        >>> nested_par = ("+", (1, 2))
+        >>> t = Tree.from_nested_parenthesis(nested_par)
+        >>> t.to_postfix()
+        [1, 2, '+']
+        >>> nested_par = ("+", (
+        ...    ("*", (3, 4)),
+        ...    2))
+        >>> t = Tree.from_nested_parenthesis(nested_par)
+        >>> t.to_postfix()
+        [3, 4, '*', 2, '+']
+        >>> nested_par = ("+", (
+        ...    ("*", (3, 4)),
+        ...    ("*", (5, 6)),
+        ...     ))
+        >>> t = Tree.from_nested_parenthesis(nested_par)
+        >>> t.to_postfix()
+        [3, 4, '*', 5, 6, '*', '+']
+        """
+        return self.apply(postfix_concatenate)
+
+
 
 class MutableTree(Tree):
 
@@ -767,6 +768,20 @@ class MutableTree(Tree):
 
         self.right_value = nright_value
 
+class LeafTree(Tree):
+
+    """ A LeafTree is a tree which act as if it is a leaf.
+    It blocks thoses methods:
+     - apply
+     - apply_on_last_level
+    """
+
+    def apply(self, *args):
+        raise AttributeError("Can't use apply on a LeafTree")
+
+    def apply_on_last_level(self, *args):
+        raise AttributeError("Can't use apply on a LeafTree")
+
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