Friday, July 27, 2007

Tool Power and Why I Use Eclipse

I was talking with Kyle the other day about how with programming languages, when you look up at languages more powerful than the ones you know, all you see is what you already know and the supposedly more powerful languages seem not so great. However, when you look down at less powerful languages, it's obvious that they are less powerful. I'm not talking about computational power, as all Turing-complete languages can express all the same programs. It's more about abstractions. Paul Graham describes this more in depth calling it the Blub Paradox.

That is all very well and interesting in itself. But if you accept it, you must also accept its implications. Namely, it makes sense to learn and use more powerful languages.

But it's not just about languages. It's about tools. Yesterday at work, I had a discussion with two co-workers about the differences between Emacs and Eclipse as IDEs. Them both being advocates of Emacs, I figured I could get the lowdown on it from them since I only use it occasionally and am not an expert. For writing Java (unfortunately, yes, I must do this at my current job), I prefer Eclipse. But I'm open to using other more productive tools. So I thought to myself, if Emacs is so great, maybe I can find out from one of these guys why, and then perhaps I'll switch.

Basically, their argument came down to 2 things. First of all, Emacs can be more easily extended than Eclipse which has a clumsy plugin system. And secondly, only Emacs allows you to re-map the key bindings which is extremely helpful for writing code, which is where you spend the majority of your effort compared to other tasks you'd use an IDE for.

However, there's one feature of Eclipse in particular (there are others too, but I'll not go into them) that Emacs does not have and neither of the guys I talked to knew of a standard extension out there that already does this. It is the code refactoring features — specifically, renaming variables, classes, and packages.

I admit, any programmer is going to spend 10 times as much of his time on writing code. Renaming things is a rare task comparatively. However, when it must be done in Emacs or editors that don't support this, you must use regex replacing. And this is both tedious and error-prone. Textual find and replace will always be error-prone since it does not take into account scoping rules of the language.

The fact that Eclipse allows you to do this correctly every time means that the cost of renaming drops to practically zero. This means you no longer have to avoid it, which in this case means you no longer have to plan ahead to try to avoid it in the future. But refactoring and renaming is inevitable. In fact, the more often you refactor the better because it prevents code complexity and messiness from creeping in. But say you wanted to try to think of the right name from the beginning to try to prevent having to refactor it later. It is impossible to know the correct name for a thing when you create it because code is fluid — it never stops changing. Requirements change, goals change, scope changes. And so too must the code. Moreover, as you design a solution to a problem, your understanding of the problem changes. So even if the actual problem doesn't change, your understanding of how to most efficiently solve that problem will change. Thus, refactoring including renaming is absolutely inevitable to keep the code as close as possible to the model in your mind.

So why should I use an IDE that is oblivious to such things, forcing me to think about more things than I have to. The details which are solely a result of code being expressed in text.

It's true that such a feature could probably be made as an Emacs extension. I do not doubt this at all. But the fact that it is not already done means that like Lisp over C, or C over machine-code, Eclipse is more powerful than Emacs. And this is obvious looking down the power continuum.

...And as for the whole key bindings thing, personally I almost never find my keystroke rate as the bottleneck. Writing code is usually limited by my conceptual understanding and the translation of ideas into the language I'm writing in. But maybe that's just me.

So I don't think the guys I had this conversation with got this out of it, but because of this conversation, I realized that Eclipse is a more powerful tool than Emacs (for editing Java), and I don't plan on switching any time soon.

Post Post: Since writing this I've realized I've fallen into the same trap as others. Namely, the trap of not seeing the power of something you don't understand. I've done the exact same thing that users of less powerful tools and languages do when they look at something more powerful. I've disregarded the importance of re-mapping key bindings w/o actually getting to know them. It's possible this is a huge gain. This doesn't change the fact that Eclipse is more powerful in other respects. So it is really a value-judgment of mine that the cost of typing slowly is less than having to refactor things manually. But I won't know for sure until I learn and use the more powerful features of Emacs.

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