All variable/pattern bindings are monomorphic unless a signature is given

(one of the proposals for reforming the MonomorphismRestriction)

For:

• 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:

• 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.