instructions.md

In this exercise, you've been tasked with writing the software for an encryption device that works by performing transformations on data. You need a way to flexibly create complicated functions by combining simpler functions together.

For each task, make use of a closure and return a function that can be invoked from the calling scope.

All functions should expect integer arguments. Integers are also suitable for performing bitwise operations in Elixir.

1. Create an adder

Implement Secrets.secret_add/1. It should return a function which takes one argument and adds to it the argument passed in to secret_add.

adder = Secrets.secret_add(2)
adder.(2)
# => 4

2. Create a subtractor

Implement Secrets.secret_subtract/1. It should return a function which takes one argument and subtracts from it the secret passed in to secret_subtract.

subtractor = Secrets.secret_subtract(2)
subtractor.(3)
# => 1

3. Create a multiplier

Implement Secrets.secret_multiply/1. It should return a function which takes one argument and multiplies it by the secret passed in to secret_multiply.

multiplier = Secrets.secret_multiply(7)
multiplier.(3)
# => 21

4. Create a divider

Implement Secrets.secret_divide/1. It should return a function which takes one argument and divides it by the secret passed in to secret_divide.

divider = Secrets.secret_divide(3)
divider.(32)
# => 10

Make use of integer division.

5. Create a "and"-er

Implement Secrets.secret_and/1. It should return a function which takes one argument and performs a bitwise and operation on it and the secret passed in to secret_and.

ander = Secrets.secret_and(1)
ander.(2)
# => 0

6. Create a "xor"-er

Implement Secrets.secret_xor/1. It should return a function which takes one argument and performs a bitwise xor operation on it and the secret passed in to secret_xor.

xorer = Secrets.secret_xor(1)
xorer.(3)
# => 2

7. Create a function combiner

Implement Secrets.secret_combine/2. It should return a function which takes one argument and applies to it the two functions passed in to secret_combine in order.

multiply = Secrets.secret_multiply(7)
divide = Secrets.secret_divide(3)
combined = Secrets.secret_combine(multiply, divide)

combined.(6)
# => 14