Fix negation bug in numeric power (e.g. -2^8).

src/rules/numerics.py

@@ -271,7 +271,7 @@ def match_raise_numerics(node):
     r, e = node
 
     if r.is_numeric() and e.is_numeric() and not e.negated:
-        return [P(node, raise_numerics, (r, e))]
+        return [P(node, raise_numerics, (r, e, node.negated))]
 
     return []
 
@@ -282,9 +282,9 @@ def raise_numerics(root, args):
     (-2) ^ 3  ->  -8
     (-2) ^ 2  ->  4
     """
-    r, e = args
+    r, e, negated = args
 
-    return Leaf(r.value ** e.value, negated=r.negated * e.value)
+    return Leaf(r.value ** e.value, negated=r.negated * e.value + negated)
 
 
 MESSAGES[raise_numerics] = _('Raise constant {1} with {2}.')

tests/test_rules_numerics.py

@@ -155,10 +155,16 @@ class TestRulesNumerics(RulesTestCase):
 
     def test_raise_numerics(self):
         l1, l2 = root = tree('2 ^ 3')
-        self.assertEqualNodes(raise_numerics(root, (l1, l2)), L(8))
+        self.assertEqualNodes(raise_numerics(root, (l1, l2, 0)), L(8))
 
         l1_neg, l2 = root = tree('(-2) ^ 2')
-        self.assertEqualNodes(raise_numerics(root, (l1_neg, l2)), --L(4))
+        self.assertEqualNodes(raise_numerics(root, (l1_neg, l2, 0)), --L(4))
 
         l1_neg, l2 = root = tree('(-2) ^ 3')
-        self.assertEqualNodes(raise_numerics(root, (l1_neg, l2)), ---L(8))
+        self.assertEqualNodes(raise_numerics(root, (l1_neg, l2, 0)), ---L(8))
+
+        l1_neg, l2 = root = tree('-((-2) ^ 3)')
+        self.assertEqualNodes(raise_numerics(root, (l1_neg, l2, 1)), ----L(8))
+
+        l1_neg, l2 = root = tree('-(2 ^ 3)')
+        self.assertEqualNodes(raise_numerics(root, (l1_neg, l2, 1)), -L(8))