Use Aho–Corasick algorithm to batch pattern matching on literal expressions

[kostmo]

Use "Alfred–Margaret" Haskell implementation.

[ezyang]

If you want regexes to work you can do https://github.com/livegrep/livegrep Nelson has blogged about the algorithm at https://blog.nelhage.com/2015/02/regular-expression-search-with-suffix-arrays/