1 files changed, 19 insertions, 9 deletions
diff --git a/Lib/ast.py b/Lib/ast.py
index 6d92eddddc..fd5dfdba67 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -29,12 +29,12 @@ from _ast import *
 from _ast import __version__
 
 
-def parse(expr, filename='<unknown>', mode='exec'):
+def parse(source, filename='<unknown>', mode='exec'):
     """
-    Parse an expression into an AST node.
-    Equivalent to compile(expr, filename, mode, PyCF_ONLY_AST).
+    Parse the source into an AST node.
+    Equivalent to compile(source, filename, mode, PyCF_ONLY_AST).
     """
-    return compile(expr, filename, mode, PyCF_ONLY_AST)
+    return compile(source, filename, mode, PyCF_ONLY_AST)
 
 
 def literal_eval(node_or_string):
@@ -64,6 +64,18 @@ def literal_eval(node_or_string):
         elif isinstance(node, Name):
             if node.id in _safe_names:
                 return _safe_names[node.id]
+        elif isinstance(node, BinOp) and \
+             isinstance(node.op, (Add, Sub)) and \
+             isinstance(node.right, Num) and \
+             isinstance(node.right.n, complex) and \
+             isinstance(node.left, Num) and \
+             isinstance(node.left.n, (int, long, float)):
+            left = node.left.n
+            right = node.right.n
+            if isinstance(node.op, Add):
+                return left + right
+            else:
+                return left - right
         raise ValueError('malformed string')
     return _convert(node_or_string)
 
@@ -140,8 +152,6 @@ def increment_lineno(node, n=1):
     Increment the line number of each node in the tree starting at *node* by *n*.
     This is useful to "move code" to a different location in a file.
     """
-    if 'lineno' in node._attributes:
-        node.lineno = getattr(node, 'lineno', 0) + n
     for child in walk(node):
         if 'lineno' in child._attributes:
             child.lineno = getattr(child, 'lineno', 0) + n
@@ -192,9 +202,9 @@ def get_docstring(node, clean=True):
 
 def walk(node):
     """
-    Recursively yield all child nodes of *node*, in no specified order.  This is
-    useful if you only want to modify nodes in place and don't care about the
-    context.
+    Recursively yield all descendant nodes in the tree starting at *node*
+    (including *node* itself), in no specified order.  This is useful if you
+    only want to modify nodes in place and don't care about the context.
     """
     from collections import deque
     todo = deque([node])