4 Dec
2013
4 Dec
'13
8:05 p.m.
Extensible Effects designed specifically to separate a client (the requestor of an action) from a handler, the executor of an action. A logging client merely requests a string to be logged. It has no idea what happens when that request is executed. Therefore, the same client can be used with several handlers, even within the same expression. One can also build various interceptors, such as logIntercept, which is similar to Unix' tee.
The following file illustrates how to solve the problem with all three scenarios. http://okmij.org/ftp/
I forgot to complete the link! I'm very sorry. Here is the correct link to the code solving the posed problem: http://okmij.org/ftp/Haskell/extensible/WriterEx.hs