higher order functions

adder.py

def adder(x):
    def add_x(n):
        return n + x
    return add_x

add_1 = adder(1)
add_2 = adder(2)
add_42 = adder(42)

x = 10

print(add_1(x))
print(add_2(x))
print(add_42(x))

def general_poly(L):
    exp = range(len(L) - 1, -1, -1) 
    coef = L[:] # make a copy to protect from side-effects.
    def apply_poly(x):
        result = 0
        for c, k in zip(coef, exp): 
            result += c*x**k
        return result
    return apply_poly


# even shorter way of defining apply_poly: sum(c*x**k for c, k in zip(coef, exp))

def general_poly(L):
    exp = range(len(L) - 1, -1, -1) 
    coef = L[:] # make a copy to protect from side-effects.
    def apply_poly(x):
        return sum(c*x**k for c, k in zip(coef, exp))
    return apply_poly