Net::LDAP is a perl module too, one of the things it does is search, so 3/4 of the words are not just matched literally, but are the right kind of net (not fishing or stockings), the right kind of ldap , the right kind of search.
You claim there is nothing related to ruby on that page, yet how many times must people have linked to both those languages from a webpage, perhaps alongside other related terms like python?
Its not perfect, and it's not magic, but is that really the level we expect from Google, so much so that we're in a huff if we have to scroll past one easily discounted search result?
They had to put a lot of effort into a search system that can ignore words that you're searching for. I'm wondering why that's necessary when I can clearly get better search results when all of my search terms are included.
Yup!
Try searching for "ruby net::ldap search", without the quotes. For me, a CPAN page is the second result. (This is even logged out, in a chrome incognito window, so no cookies are sent to google.) That page doesn't have "ruby" or anything related to "ruby" on it, at all.
But even if I was searching for something esoteric like an error message, it's much more helpful to give me no results than it is to give me irrelevant ones. Irrelevant results just waste my time clicking/skimming through them, where an empty result set will signal to me very clearly that what I'm searching for doesn't make sense.