[rkangel]

> Although it usually isn't necessary, it makes drastic improvements to the quality of error messages.

It also provides valuable documentation. You can usually work out what a function does from just its type (and quite often, that's all you have to work with).

[papln]

> just its type (and quite often, that's all you have to work with).

which is a weakness in the culture of Haskell library authors and/or the ecosystem for contributing documentation patches.

[rkangel]

Couldn't agree more. My recent experiences with Rust and especially Elixir have set high standards.