I guess I've never run into issues where a map or filter slowed me down for debugging, most languages will pretty easily show you where the error occurred. And if you're `map`ping and `filter`ing with pure functions, debugging is pretty simple because you just need the input that went into the buggy function. A good compiler will also optimize the closures into something you'd write by hand in Go. Overall I'm glad to see Go get these nice tools for more easily working with collections.