sub _expand_list {
my ($self, undef, $expr) = @_;
return { -op => [
- ',', map $self->expand_expr($_),
+ ',', map $self->expand_expr($_),
@{$expr->{-op}}[1..$#{$expr->{-op}}]
] } if ref($expr) eq 'HASH' and ($expr->{-op}||[''])->[0] eq ',';
return +{ -op => [ ',',