Harry Potter and Bilbo Baggins: Two Approaches to Magic

There’s a lot of magic in modern programming.

When I say “magic”, I really mean “sufficiently-advanced technology”. And when I say “sufficiently-advanced technology”, I really mean “library that you have no fricking idea what the kowloon putonghua it’s doing, but you use it anyway because it makes your job so much easier.”

There are lots of libraries that I have no idea what the mugu gaipan it’s doing to accomplish what it does. Just today, I confronted yet another one: Mockito, the mock object library for Java. Some of what it does, I know it does with reflection. Some, I can’t even imagine how it does it without hacking the bytecode. (It doesn’t. PowerMock, on the other hand, does hack the bytecode. It’s like adding capabilities to C by building a library that opens up a binary as if it were its diary, writes in a bunch of bits, and closes it up again. It’s bionic programs.)

Some people probably wouldn’t be bothered by this. They would use the magic without understanding it, happy that they have these magical artifacts to help them do their job. On the other hand, all this magic drives me starkers. I complained in my post on web frameworks that I didn’t like Rails because, as Princess Jasmine said breathlessly, “It’s all so magical!” Then, later, I tried Rails again, and all of a sudden, it didn’t bother me. What I didn’t realize at the time was that I had spent several months between those two incidents reading the odd article on metaprogramming, usually in a Lisp/Clojure context but sometimes also pertaining to Python and Ruby. A lot of these articles would drop little hints about how RSpec and ActiveRecord were implemented. By the time I came back to Rails, it suddenly wasn’t so magical, because I could see the threads of fate behind the tapestry, weaving themselves into finders and schema definitions and migrations.

I’m not going to pass judgment on people who aren’t bothered by the magic. I’m not going to say they’re ruining programming or whatever. Frankly, most of this magic is pretty well packaged up; if you ever do have problems with it, just Google whatever cryptic passage flashes on screen and you’ll find a tome of lore with the answer you seek. In practice, this is what I have to do most of the time because otherwise I would never get anything done. So I can’t blame anyone if this doesn’t bother them.

However, this does remind me of a difference in approach between two famous fantasy heroes, Bilbo Baggins and Harry Potter.

Bilbo Baggins is a hobbit. He has a mithril vest and a magic sword, Sting, that glows in the presence of orcs, and a magic ring that turns him invisible when he wears it. He doesn’t question how or why they work; they work, so he uses them to fight with the goblins, battle a troll, and escape in a barrel from the Elf-King’s hall. (If you’re not familiar with the story, you can find out all about it from the original work. Just Google “The Ballad of Bilbo Baggins”.)

Bilbo hangs out with Gandalf, a wizard, and Elrond, an elf lord. Wizards can do magic. So can elf lords. Bilbo doesn’t know or care why or how. They just can; he accepts it.

For the most part, this strategy works for Bilbo. He survives all sorts of things that would have killed a lesser man, becomes fantastically rich, and ends up sailing off into the West to be sponge-bathed by elf maidens in his dotage. He does run into a rather nasty edge case fifty years on, when it turns out the magic ring is actually the One Ring to rule them all, created by the Dark Lord Sauron in the fires of Mordor. But by now, he’s retired, so it’s really someone else’s problem.

Like Gandalf, Harry Potter is a wizard. Unlike Gandalf, Harry Potter didn’t spring into creation fully formed and able to do magic just because some cosmic guy played a harp. Harry Potter had to slave away for six years learning magic at Hogwarts. (It would have been seven years, but destroying Lord Voldemort’s Horcruxes gave him enough extracurricular credit to skip a year, sort of like doing a year-abroad in Muggle colleges, except with more death.) Harry had to take all kinds of crap to learn magic; he had to put up with Snape bullying him, and McGonagall riding him to win at Quidditch, and he had to stay up until 1 AM writing essays full of ludicrous made-up garbage for Professor Trelawney. He had to deal with Dumbledore, who refused to ever tell him anything straight out, instead making him engage in some insane version of the Socratic method where you die if you don’t guess right.

At the end of all this, Harry Potter still isn’t that powerful. He manages to do the Imperius Curse and Sectumsempra, but that doesn’t help him much since those are both illegal. After six years of slaving away, it’s hard to see how Harry Potter is more powerful than he was when he started.

In the Harry Potter world, magic is hard. There are some pre-packaged artifacts to help you, like the invisibility cloak, but to be really effective at magic, you have to learn it. You have to study hard. Harry Potter doesn’t really study hard. Maybe I should have used a different example, like His Dark Materials, or Edward Elric. But Harry Potter works; while he does benefit from pre-packaged artifacts like the Invisibility Cloak and the Elder Wand, there’s always the implication that anyone smart and hardworking can learn how those things work, and even reproduce or improve on them.

It bugs me to trust anything that can think if I can’t see where it keeps its brain. It bothers me if I can’t understand how something is implemented. It bothers me when I can’t understand how something is even possible without bytecode manipulation, and I want to know the answer, even if the answer is “it’s not possible without bytecode manipulation”. I take a Harry Potter approach to programming.

Well, here’s something else we can all fight about! Soon we’ll be insulting people by calling them hobbit programmers.

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