There is no reason that side effects have to be difficult to debug. You can think of the lookup chain for a variable as being part of a data structure being pa

There is no reason that side effects have to be difficult to debug. You can think of the lookup chain for a variable as being part of a data structure being passed in to a function. It is just as easy to design a convoluted data structure that gets passed in to a function as it is to design a convoluted object hierarchy. The difference is that you can't get implicit lookups for free in an fp language unless you implement something like messageSend(name, obj, args).