First point, lazy evaluation incurs a mutation when the whnf is reduced. However, this mutation occurs at most once and after that the value is immutable just like in SML. Furthermore, the update is not directly exposed to the programmer and thus the compiler can implement it in a way that works efficiently in the presence of generational GC. See the GHC papers on how.
Second point, on polymorphic overloading he claims that Haskell "allow run-time resolution of overloading". Mark P. Jones and others have show how this overhead can be largely eliminated via partial evaluation applied to the type dictionaries. The use of polymorphic overloading is pervasive in Haskell code because it's incredibly useful so the "apparently small gains" is complete and utter nonsense.
In many ways O'Caml is a better SML than SML, but Haskell, and especially the GHC variant, has a type system that is light years ahead of both.
In the modern world there are many variations on the theme, but the language Rust (which borrows many ideas from these) might become the most popular yet.
I don't think it's unreasonable to point out that some of the assertions didn't stand the test of time, but I've (maybe unfairly?) read your comment as critical of the paper despite context.
Not true. Haskell does not have neither subtyping nor row and structural polymorphism for example.
* A less verbose syntax (want examples?) and less bizarre syntax :) Clearly subjective, but IMhO Haskell is a lot cleaner
* Constructors starts with uppercase, avoiding the issue the issue related to misspelled constructors (and allowing most editors highlight the constructor)
* Type-classes allow for sane overloading of functions and operands, solving the int/float problem of SML, but extending far beyond just that.
* As he mentions: the infix operator and the export from modules are both fixed in Haskell
* Supports binary numbers (sure, it's a trivial library issue, but possible because of type classes allow extending the concept of numbers)
* The polymorphic equality is solved in Haskell, again, with type classes, allowing us to define equality to any user defined type in a way that makes sense for it (including the set example)
* List concatenation is right associative (he mentions SML's left associative @ as a problem)
* SML's overflow on + problem are solved by not having overflow (j/k, Haskell lack of overflow on integers is a serious problem IMO, but other than making Int === Integer there's no easy solution).
> Magic wands are famously difficult to control ....
In the references:
15. J. K. Rowling. Harry Potter and the Philosopher’s Stone. Bloomsbury Childrens, London,
I definitely did not read the entire paper in detail considering it's length. However, he brings up ML's type system a lot. I thought that was one ML's main advantages. Although, at the same time criticizing some of the decisions or results from those decisions.
He doesn't? He quotes an anonymous reviewer and points out that the type system is not very restrictive and well worth it.