Monadic Code In Haskell

[atravers]

That’s where it shines […]

…like the proverbial “gilded cage” where I/O is concerned:

Using unsafePerformIO safely?

A colleague of mine Victor Miraldo asked me today whether I know how to use unsafePerformIO safely. And I realized I have no idea. Do you? Or do you know of an existing blog post / other resource that addresses this? Context: Victor is writing a program that needs to call out to an SMT solver. An SMT solver acts like a pure function: it gets information in and then deterministically produces a result based (only) on its input. But because the SMT solver is invoked via a separate process, the in…