Comprehesions are more readable in the sense that they read more like "English" or "natural language". Unfortunately they're inherently non-composable and make

Comprehesions are more readable in the sense that they read more like "English" or "natural language". Unfortunately they're inherently non-composable and make refactoring harder. d0m's Moka example (https://news.ycombinator.com/item?id=6150944 https://news.ycombinator.com/item?id=6150944) is closer to composable. I would suggest the following modification. Instead of chaining methods, have a function "chain" which composes functions. We could then write chain(do(string.split, '+'), keep(lambda x: x != ""), map(int), reduce(moka.add)) If I decided that removing blanks and converting to int was a concept that was worth capturing in its own function, all that I need to do is splice out part of the chain as is. non_blanks_to_int = chain(keep(lambda x: x != ""), map(int)) chain(do(string.split, '+'), non_blanks_to_int, reduce(moka.add)) No modifications were required. It's more complicated with comprehensions. Of course it's still possible, but it's one more unneccessary grain of sand in the mechanism. Doing the same with the imperative version would be nigh-on impossible. Come to my FP days talk in Cambridge, UK, Thursday 24th October, 2013 if you want to hear more about this! http://lanyrd.com/2013/fpdays/sckzkz/ http://lanyrd.com/2013/fpdays/sckzkz/