use "-unwanted, +wanted" type switches for the search syntax.

I would like to suggest an idea...
use "-unwanted, +wanted" type switches for the search syntax. An alternative addition to syntax might also contain a # type of switch for number of results for this switch limited to #5+unwantedtext for example in this case limiting results that contain or do not contain "-" to the first 5 results, as well could be used to limit results overall to # number of hits.