But the error that this article complains about is from a compiler that's 3 years old and 4 major releases out of date, and doing the exact same thing on the latest version will give you a better error.
GHCi, version 9.2.1: https://www.haskell.org/ghc/ :? for help
ghci> 1 + [2, 3]
<interactive>:1:1: error:
* No instance for (Num [Integer]) arising from a use of `it'
* In the first argument of `print', namely `it'
In a stmt of an interactive GHCi command: print it