Implementing Patchable

Here's a look at the Patchable trait.

#![allow(unused_variables)]
fn main() {
pub trait Patchable<P> {
    fn apply_patch(&mut self, patch: P);
}

P is the delta encoding that was generated by the Diffable.create_delta_towards method.

Different types will have different patches that need to be applied in different ways.

Let's talk a look at an i128, one of the more trivial Patchable types.

#![allow(unused_variables)]
fn main() {
implement Patchable<Option<i128>> for i128 {
    fn apply_patch(&mut self, patch: Option<i128>) {
        if let Some(patch) = patch {
            *self = patch;
        }
    }
}
}

Here's a slightly more complex example patch function.

#![allow(unused_variables)]
fn main() {
enum CustomPatchExample {
    Replace(i128),
    Add(i16)
}

// This is not how the real implementation for i128 looks.
implement Patchable<CustomPatchExample> for i128 {
    fn apply_patch(&mut self, patch: CustomPatchExample) {
        match patch {
            CustomPatchExample::Replace(new) => {
                *self = new;
            }
            CustomPatchExample::Add(add) => {
                self += add as i128;
            }
        }
    }
}
}