Should I use GHC Haskell extensions or not?

Question

As I am learning Haskell, I see that there is a lot of language extensions used in real life code. As a beginner, should I learn to use them, or should I avoid them at all cost?

Answer 1

Generally speaking people do use GHC extensions quite heavily, because they're so useful and Haskell 98 is quite old. Once there's a more up to date standard people may make more effort to stick to it.

You can find the status of proposals for the next standard here.