Sort by Number of Calls

Create a function that takes a list of functions and sorts them in ascending order based on how many calls are needed for them to return a non-function.

Examples

f1 = lambda: "hello"
# f1() ➞ "hello"

f2 = lambda: lambda: "innokodakademija"
# f2()() ➞ "innokodakademija"

f3 = lambda: lambda: lambda: "user"
# f3()()() ➞ "user"

func_sort([f2, f3, f1]) ➞ [f1, f2, f3]
# [f2, f3, f1] ➞ [2, 3, 1] ➞ [1, 2, 3] ➞ [f1, f2, f3]

func_sort([f1, f2, f3]) ➞ [f1, f2, f3]
# [f1, f2, f3] ➞ [1, 2, 3] ➞ [1, 2, 3] ➞ [f1, f2, f3]

func_sort([f2, "func"]) ➞ ["func", f2]
# [f2, "func"] ➞ [2, 0] ➞ [0, 2] ➞ ["func", f2]

Notes

• Treat non-functions as needing zero calls.
• Every function will be called with empty parameters.
• Every function will need to be called at least once.
• The potentially returned values include ints, floats, and lists, among others.