Deparse list repetition assignment properly

This only applies to the almost useless case of nothing but a repetition
on the lhs of list assignment:  ((undef)x3) = foo();

Other cases where the repetition is part of a larger list already
deparsed correctly.

Checking whether the lhs begins with a parenthesis is not sufficient
to determine whether the lhs is parenthesized.  I believe repetition
is the only binary op other than the comma that is allowed on the
lhs, so we can just check for that in the op tree.

diff --git a/lib/B/Deparse.pm b/lib/B/Deparse.pm
index ea82ebd..ade6a78 100644 (file)
--- a/lib/B/Deparse.pm
+++ b/lib/B/Deparse.pm
@@ -2542,9 +2542,17 @@ sub binop {
     if ($flags & SWAP_CHILDREN) {
        ($left, $right) = ($right, $left);
     }
+    my $leftop = $left;
     $left = $self->deparse_binop_left($op, $left, $prec);
     $left = "($left)" if $flags & LIST_CONTEXT
-               && $left !~ /^(my|our|local|)[\@\(]/;
+                    and    $left !~ /^(my|our|local|)[\@\(]/
+                        || do {
+                               # Parenthesize if the left argument is a
+                               # lone repeat op.
+                               my $left = $leftop->first->sibling;
+                               $left->name eq 'repeat'
+                                   && null($left->sibling);
+                           };
     $right = $self->deparse_binop_right($op, $right, $prec);
     return $self->maybe_parens("$left $opname$eq $right", $cx, $prec);
 }

diff --git a/lib/B/Deparse.t b/lib/B/Deparse.t
index 98a19c8..a206529 100644 (file)
--- a/lib/B/Deparse.t
+++ b/lib/B/Deparse.t
@@ -358,6 +358,9 @@ $test /= 2 if ++$test;
 # list x
 -((1, 2) x 2);
 ####
+# Assignment to list x
+((undef) x 3) = undef;
+####
 # lvalue sub
 {
     my $test = sub : lvalue {