Have you tried doing Type-Driven Development? IME, most of the time constraints are determined through types first with the code being done later tends to repla

Have you tried doing Type-Driven Development? IME, most of the time constraints are determined through types first with the code being done later tends to replace the game of "what kind of complex and non-obvious types fit my code the most" with a "oh, the implementation is obvious" reaction. It also makes it easier to determine what behavior is worth testing and which ones are already covered by your types, if you tend to write tests last. If instead you're used to Test-Driven Development you can do types->tests->code.