public function bindBackspace(Readline $self)
{
$cursor = '';
if ($self->getLineCurrent() > 0) {
if ($self->getLineLength() == ($current = $self->getLineCurrent())) {
$self->setLine(mb_substr($self->getLine(), 0, -1));
} else {
$line = $self->getLine();
$current = $self->getLineCurrent();
$tail = mb_substr($line, $current);
$movecursor = $self->getLineLength() - $current;
$cursor = "[{$movecursor}D";
$self->setLine(mb_substr($line, 0, $current - 1) . $tail);
$self->setLineCurrent($current - 1);
}
}
$prefix = $self->getPrefix();
$self->clearTerminalLine();
$self->setBuffer("\r" . $prefix . $self->getLine() . $cursor);
return $self::READ_CONTINUE;
}