In the first chapter, we introduced the concept of a tower of abstractions, and the idea that every abstraction is a simplified lever to hidden complexity. The principle of abstraction within programming states the following:
Implementation should be separate from interface.
An implementation is the complex underside of an abstraction: the part that it's hiding. The interface is the simplified topside. That is why we say that abstraction is a simplified lever to hidden complexity. The craft of creating abstractions that separate implementation from interface to just the right degree is not as simple as it may seem. As such, the programming world provides two warnings for us:
- Don't repeat yourself (DRY): A warning that tells us to avoid writing code that duplicates other code we have written. If you find yourself having to repeat yourself, then...
