> you can ship refinement type specifications within plain Haskell packages That's pretty great. I've heard comments that using LH for performance foo bar

> you can ship refinement type specifications within plain Haskell packages That's pretty great. I've heard comments that using LH for performance foo bar = frobnicate (head bar) -- LH has checked that bar is nonempty, save a cycle or two would become unsafe if it's put in a library depended on by a client that doesn't check it with LH. It seems like this is issue pretty much solved now :-)