It seem to propose an abstraction where we separate the I/O part from the "elaboration" part of a programs, so that our programs are entirely pure. But i don't understand why the import system and why only the compiler can read and write?
Why can't we have the same benefits by using multi-threading/process? we can have "pure" thread and "i/o" thread that communicate with message passing? i feel like I'm missing something from the article.
* "Why should we limit I/O to the compiler"?
Think of the compiler or interpreter as a small trusted kernel. It's a mostly fixed code base that you can inspect and audit. The programs that it compiles or interpret on another hand don't have to be trusted because they are perfectly sandboxed. They are effect-free purely functional code
* "Why not use multi-threading for communication?"
This is (in my eyes) the real problem that I'm trying to solve. Using effects as a message bus for composing code seems incredibly awkward and primitive, like explicitly managing stack registers.