my ($self) = @_;
my $hyp = $self->current_hypothesis;
return undef unless my $step = $self->next_step;
- my ($new_ss, $alt_step) = $step->apply_to($self);
- if ($new_ss) {
- return $new_ss->but(
- alternatives => [
- ($alt_step
- ? [ $hyp, $alt_step ]
- : ()),
- @{$new_ss->alternatives}
- ],
- );
- }
- if ($alt_step) {
- return $self->but(next_step => $alt_step);
- }
+ my ($new_ss) = $step->apply_to($self);
+ return $new_ss if $new_ss;
my ($first_alt, @rest_alt) = @{$self->alternatives};
return undef unless $first_alt;
trace 'search.backtrack.rewind_to' => $first_alt->[1];