[imiric]

But projects like these go far beyond just constraints. They're a library of utility functions for doing arithmetic, working with lists, and even sorting. All of this can be equally accomplished by a regular and well-established library that doesn't depend on exotic, and possibly undocumented, features of a type system, and without incurring build time penalties.

[amw-zero]

Well, "constraint" is a very abstract word. What you're describing are still constraints, they're just complex constraints.

The type vs. no type argument is basically: what's the cutoff line for constraints that are worth encoding as types or not?