RE: [External] : Any package for boolean search?

[Drew Adams]

> Boolean Search: This is a method where search terms are combined using
> boolean logic, as described by the operators AND, OR, and NOT.
> 
> I would like to implement this classic into the website search. And I
> wish to keep it simple.

I can't help you wrt website searches etc.  Hopefully
someone else will.
___

But FWIW, Isearch+ provides such functionality, on
the fly, for incremental buffer/file searching.

https://www.emacswiki.org/emacs/DynamicIsearchFiltering