Don Syme on type-level programming Lassi Kortela 12 Nov 2022 22:29 UTC

Here's a landmark post on the issue of types by the lead designer of F#
(Microsoft's ML for the .NET platform):
https://github.com/fsharp/fslang-suggestions/issues/243#issuecomment-916079347

This is the best summary I've read on the pitfalls of making type
systems too complex. Similar concerns are periodically echoed around the
net (Haskell and Rust are too complex yet not expressive enough, etc.)
but this post adds them all up, and is written by someone who has
invested his career into making static types work well for application
programming.

The criticisms are broadly similar to those made of object-oriented
excess during the heyday of C++ and Java: Slow compiles, baffling
compiler errors, perennial struggle to find the "right" way to make
fundamentally ambiguous classifications; writing meta-code instead of
actual code.