All variable/pattern bindings are monomorphic unless a signature is given
(one of the proposals for reforming the MonomorphismRestriction)
- Simpler than the M-R
- Polymorphism in local variable bindings is rare (but less rare at the top-level), and can always be recovered with a type signature
- Against the spirit of Haskell - shouldn't compromise expressiveness for performance by default
- Already huge potential for ruining your performance without the M-R, why introduce such draconian measures just for this?
- Monomorphic bindings lead to hard to understand errors when polymorphism was expected
- Haskell doesn't define an operational semantics so introducing a concept of sharing into the report would be odd.