Beginner's Guide to Abstraction
One hard fought lesson I’ve learned over the years is that copy/paste is often a very good solution. If the downside is that a developer has to manually spray a change to 50 different locations with the same copy/pasted implementation snippet, that’s really fine. Even for 500 or possibly 5000 locations is fine, with a good editor available or other tooling. Testing these changes for correctness is easy.<p>Meanwhile the cost for getting an abstraction wrong is often far worse. And it’s really easy to get wrong because abstractions by their nature are always built based on yesterday’s data plus good intentions. People are arguing about subjective theories and unmeasured concepts of extensibility, wasting time arguing about Liskov Substitution Principle, SOLID, dependency injection, type system design patterns, etc., but it’s mostly junk that just adds code bloat.<p>Obviously there are other solutions that don’t require premature abstraction or copy/paste 1000 times (like simple module functions as the core unit of reusability, or a macro system for code injection). But the point is copy/paste gets a bad wrap. It’s simple, straightforward, easy to automate, easy to test, and adds no extra concepts to the code.<p>“Functional core, imperative shell” is the best advice I’ve found. Ruthlessly avoid object orientation, and when you need it, stick to extremely shallow inheritance. Make everything a module function, and when you write data structures, don’t give them member function logic for their core functions (like search, sort, add items, remove items), rather create functions that accept data structure instances as arguments and perform these operations with no class-like internal state.