Answered off-forum.

But in brief: what we're writing in the project isn't really a program, but a library (admittedly a very small one) - a set of functions serving some common purpose. So as library maintainers, we can just declare: caesar_decrypt will never exist without caesar_encrypt also existing, because what would be the point of a decryption function without an encryption function?

So we are entitled to ignore that possibility, and write code that's simple and readable.

Cheers

Arran

ANONYMOUS wrote:

Reimplementing the logic seems unecessary and redundant, as suitable code already exists in another function. It potentially also improves the readability of the function. On the other hand, it prevents any potential separation of caesar_decrypt from caesar_encrypt. For caesar_decrypt to work, it must always be able to access the caesar_encrypt function, which, if we are writing our program for future use by others, could be an issue. I am still uncertain of whcih implementation to go with, do you have any pointers? Thank you