Old information in Extensions to data types and type synonyms
The Release notes for version 7.6.1 says
http://www.haskell.org/ghc/docs/7.6.1/html/users_guide/release-7-6-1.html The behavior of the TypeOperator extension has changed: previously, only type operators starting with ":" were considered type constructors, and other operators were treated as type variables. Now type operators are always constructors.
But this change isn't reflected in the User's Guide.
http://www.haskell.org/ghc/docs/7.6.1/html/users_guide/data-type-extensions.html http://www.haskell.org/ghc/docs/7.6.2/html/users_guide/data-type-extensions.html http://www.haskell.org/ghc/docs/7.6.3/html/users_guide/data-type-extensions.html A type variable can be an (unqualified) operator e.g. +. The lexical syntax is the same as that for variable operators, excluding "(.)", "(!)", and "(*)". In a binding position, the operator must be parenthesised. For example: ...
I think this paragraph should be removed.