fn

The fn library contains helper functions that are related to arrai functions.

//fn.fix(f <: function) <: function

Due to the current implementation of arrai, recursive functions cannot be created without the helper function fix. fix takes the function recursive f and returns f whose recursive nature can now be utilized. For more information, please read the functions section in the introduction to arr.ai.

This function uses the concept of a fixed-point combinator.

Usage:

example	equals
let fib = //fn.fix(\fib (\n (cond (n = 0: 0, n = 1: 1, n > 0: fib(n-1) + fib(n-2), *: 0)))); fib(10)	55

//fn.fixt(f <: tuple_of_functions) <: tuple_of_function

fixt is a variant of fix. This allows mutual recursion. For more information, please read the functions section in the introduction to arr.ai.

Usage:

example	equals
let collatz = //fn.fixt((even: \t \n (cond (n % 2 = 0: [n] ++ t.even(n / 2), *: t.odd(n))), odd: \t \n (cond (n = 1: [1], n % 2 = 1: [n] ++ t.odd(3 * n + 1), *: t.even(n)))); collatz.even(6)	[6, 3, 10, 5, 16, 8, 4, 2, 1]