mpempekos / soft_testing Goto Github PK

Nicely done, this is a + for the first week (next issues will be found in the other repo of your new group).

Some minor feedback that might still be relevant to improve your Haskell skills:

• the “not equals” is /=, even though not (... == ...) is possible of course
• do not forget to η-reduce your code after you’re done playing with it, it also helps to get to the real intent behind the code: sumDigits l = findSum 0 l implies that there is some computation going on, while sumDigits = findSum 0 could clearly state that one function is defined as another with a fixed first argument.
• constructs like if (...) then True else False are not truly if-statements, there is no branches, it just says that if the condition evaluates to True, the result is True, and if it evaluates to False, it’s False… which lets me wonder, why not use the condition itself?
• the function \ (b, _) -> b is pretty standard and is called fst

Lastly, look at this piece of code:

possible_guilty:: [Boy] -> [Boy]
possible_guilty (boy:boys) = accusers boy ++ (possible_guilty boys)
possible_guilty [] = []

Essentially what happens here is an iteration through all elements from right to left, without any surprises or interruptions, and on each step we take whatever was the result on the right, and append it to the list of accusers of another element. This is a pattern realised by a higher order function called foldr, and your entire function can be programmed as:

possible_guilty boys = foldr ((++) . accusers) [] boys