Add rewrite for ExprParen

src/expr.rs

@@ -125,6 +125,23 @@ impl<'a> FmtVisitor<'a> {
         format!("{}({})", callee_str, args_str)
     }
 
+    fn rewrite_paren(&mut self, subexpr: &ast::Expr, width: usize, offset: usize) -> String {
+        debug!("rewrite_paren, width: {}, offset: {}", width, offset);
+        // 1 is for opening paren
+        let subexpr_str = self.rewrite_expr(subexpr, width-1, offset+1);
+        debug!("rewrite_paren, subexpr_str: `{}`", subexpr_str);
+        let mut lines = subexpr_str.rsplit('\n');
+        let last_line_len = lines.next().unwrap().len();
+        let last_line_offset = if lines.next().is_none() {offset+1} else {0};
+        if width + offset - last_line_offset - last_line_len > 0 {
+            format!("({})", subexpr_str)
+        } else {
+            // FIXME That's correct unless we have width < 2. Return an Optrion for such cases ?
+            format!("({}\n{} )", subexpr_str, make_indent(offset))
+        }
+    }
+
+
     pub fn rewrite_expr(&mut self, expr: &ast::Expr, width: usize, offset: usize) -> String {
         match expr.node {
             ast::Expr_::ExprLit(ref l) => {
@@ -140,6 +157,9 @@ impl<'a> FmtVisitor<'a> {
             ast::Expr_::ExprCall(ref callee, ref args) => {
                 return self.rewrite_call(callee, args, width, offset);
             }
+            ast::Expr_::ExprParen(ref subexpr) => {
+                return self.rewrite_paren(subexpr, width, offset);
+            }
             _ => {}
         }