while), and programming without loops is almost unimaginable. However, in Haskell, there is no such syntax for loops, and the basic mechanism for looping is recursion.
x, it can be defined as that number
xplus the sum of all natural numbers up to
x - 1. Let's take a closer look at what the actual execution looks like:
. The recursive case, however, applies the function to
x(the head of the list) and joins the result with the result of the recursive call on the remainder of the list (the tail of the list).