Haskell is a lazy-by-default language and the most practical way to disable laziness is that syntax extension. You can do it without the extension, but it'll t

Haskell is a lazy-by-default language and the most practical way to disable laziness is that syntax extension. You can do it without the extension, but it'll turn ugly really quick (lots of uses of the "seq" function everywhere). In general, the Haskell community is very tolerant of language extensions (people will recommend you enable about a dozen of them in every project), so this is pretty standard.