I came across this Codewars question:
Your task is to write a higher order function for chaining together a list of unary functions. In other words, it should return a function that does a left fold on the given functions.
chained([a,b,c,d])(input)Should yield the same result as
d(c(b(a(input))))
I don't really care what the answer to the problem is, I can access that on the site. What I actually need explained to me is the first function, "chained". I've never seen a function like that with 2 sets of argument in separate parenthesis, so I imagine I'm interpreting it incorrectly.. what does that mean? Thanks for the help
It is not a function with two sets of parameters, but a function that returns another function, executing the functions given as parameters one after the other.
Maybe it's clearer if you separate the line into two lines:
f = chained([a,b,c,d]) # call `chained` with functions as parameters
f(input) # call result of `chained`, which is another function