[Haskell-cafe] Martin Odersky on "What's wrong with Monads"

[Arlen Cuss]

> In standard ML you can start doing effect-based things inside a function without having to alter its type and they type of everything that uses it, and so on.
This in turn causes a break-down in the type-system where weak type variables are introduced.  We can see the pathological case for that here: http://www.cs.washington.edu/education/courses/cse505/00au/lectures/13-refs.txt

This makes regular things like curried function compositions unusable, because their polymorphicness goes away!  Such is the result of not encapsulating side-effects.

—Arlen