Haskell 2010 adds the Foreign Function Interface (FFI) to Haskell, allowing for bindings to other programming languages, fixes some syntax issues (changes in the formal grammar) and bans so-called "n-plus-k-patterns", that is, definitions of the form fact (n+1) = (n+1) * fact n are no longer allowed.(Wikipedia)

 

I was reading about haskell on wikipedia. Why they took n-plus-k-patterns off haskell?

 

And:

 

Do you know some catalog of this patterns?

 

 

 

 

 

Google reveals this

http://hackage.haskell.org/trac/haskell-prime/wiki/RemoveNPlusK

I felt afraid to search for. I thought i could only obtain the answer diving on lots and lots of techical papers.