sub my_func {
	my ( $self, $ptr_array, $value ) = @_;
	return look_right( $ptr_array, $value ) if ( $value == 0 );
	return look_left( $ptr_array, $value  ) if ( $value == @{ $ptr_array } );
	return (
		look_right( $ptr_array, $value )
		&& look_left( $ptr_array, $value )
	);
}

sub look_left {
	my ( $ptr_array, $value ) = @_;
	# ...
}

sub look_right {
	my ( $ptr_array, $value ) = @_;
	# ...
}