Can GHC warn about the uses of dangerous non-total functions?

Question

I have been writing quickly some code in Haskell, and used a dangerous non-total function, namely fromJust (where I expect a value from input). I'm going to think later what kind of error-handling style I want to use.

Can GHC help me make sure that I have got rid of all uses of dangerous non-total functions (like fromJust or head, which could crash) , give me warnings where they are.

Answer 1

GHC can warn about definitions with partial patterns with -fwarn-incomplete-patterns (though does not warn about uses of values that include incomplete patterns). Additionally, Neil Mitchell's catch attempts a slightly more detailed analysis to identify safe and unsafe invocations of partial functions. (Though of course that's an undecidable problem in general, so it won't always be right!)