Force parentheses between unary op and binary power. (#909)

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index 97393e164005404ed76951f5612d8fcd1b45fb3c..779e9d0c873eafa31dc8a660e6c1311f5c13fcfb 100644 (file)
--- a/black.py
+++ b/black.py
@@ -1643,6 +1643,19 @@ class LineGenerator(Visitor[Line]):
             node.children[2].value = ""
         yield from super().visit_default(node)
 
             node.children[2].value = ""
         yield from super().visit_default(node)
 

+    def visit_factor(self, node: Node) -> Iterator[Line]:
+        """Force parentheses between a unary op and a binary power:
+
+        -2 ** 8 -> -(2 ** 8)
+        """
+        child = node.children[1]
+        if child.type == syms.power and len(child.children) == 3:
+            lpar = Leaf(token.LPAR, "(")
+            rpar = Leaf(token.RPAR, ")")
+            index = child.remove() or 0
+            node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+        yield from self.visit_default(node)
+

     def visit_INDENT(self, node: Node) -> Iterator[Line]:
         """Increase indentation level, maybe yield a line."""
         # In blib2to3 INDENT never holds comments.
     def visit_INDENT(self, node: Node) -> Iterator[Line]:
         """Increase indentation level, maybe yield a line."""
         # In blib2to3 INDENT never holds comments.