Haskell quiz: a simple function
- by levy
I'm not a Haskell programmer, but I'm curious about the following questions.
Informal function specification:
Let MapProduct be a function that takes a function called F and multiple lists. It returns a list containing the results of calling F with one argument from each list in each possible combination.
Example:
Call MapProduct with F being a function that simply returns a list of its arguments, and two lists. One of the lists contains the integers 1 and 2, the other one contains the strings "a" and "b". It should return a list that contains the lists: 1 and "a", 1 and "b", 2 and "a", 2 and "b".
Questions:
How is MapProduct implemented?
What is the function's type? What is F's type?
Can one guess what the function does just by looking at its type?
Can you handle inhomogeneous lists as input? (e.g. 1 and "a" in one of the input lists)
What extra limitation (if any) do you need to introduce to implement MapProduct?
