I love the idea of a search engine like SymbolHound, but I find the results lacking in practice.

For example, a search for Swift's nil coalescing operator turns up nothing of relevance: http://symbolhound.com/?q=swift+%3F%3F

(Actual information about "??" in Swift for anyone interested: https://developer.apple.com/library/ios/documentation/Swift/...)

Hi, I'm the developer of SymbolHound. You're right, SymbolHound's index is a little lacking, especially for new languages. This is because it's based almost entirely on a stackoverflow data dump (http://blog.stackoverflow.com/2009/06/stack-overflow-creativ...) from when I first made it (2011). Swift was released in 2014, so there are no results. I'm planning to update it when I have the time.

Discussed a little bit 1250 days ago:

https://news.ycombinator.com/item?id=3266644

Google has the verbatim option for that.

Search Tools -> Verbatim

I tried google's verbatim but it returned no results for <$>. Meanwhile symbolhound returned several relevant stackoverflow posts.

Assuming that's Haskell, you probably want Hoogle (https://www.haskell.org/hoogle/).

For any other language, SymbolHound seems quite useful.

Yes, it is. Hoogle is brilliant and I highly recommend it to anyone that programs in Haskell.

Looks very similar to http://nerdydata.com which let's you search the source code of webpages. They don't seem to index many stackoverflow posts though..

SymbolHound seems more geared at searching docs.

(:.) haskell

no luck there

For Haskell, Hayoo[0] works well

[0]: http://hayoo.fh-wedel.de/?query=.%3A