Partial package:extra

A constraint which documents that a function is partial, and on GHC 8.0 and above produces a stack trace on failure. For example:

myHead :: Partial => [a] -> a
myHead [] = error "bad"
myHead (x:xs) = x

When using Partial with GHC 7.8 or below you need to enable the language feature ConstraintKinds, e.g. {-# LANGUAGE ConstraintKinds #-} at the top of the file.