Dynamic scoping is an effect, implicit parameters are a coeffect August 27, 2020
For the longest time, I thought of implicit parameters and dynamic scoping were basically the same thing, since they both can be used to solve similar problems (e.g., the so called “configuration problem” where you need to plumb down some configuration deep into a nested body of function definitions without defining them all explicitly). But implicit parameters have a reputation of being something you shouldn’t use (use reflection instead), whereas dynamic scoping via the reader monad is a useful and well understood construct (except for the bit where you have to monadify everything). Why the difference?