Wikipedia Chooses Lua As Its New Template Language

bonch writes "In an attempt to tackle the inefficient complexity of its current template system, Wikipedia will be adopting the Lua scripting language. Known most for its use in videogame scripting, particularly World of Warcraft, Lua is lightweight and designed for easy integration into existing applications. The transition is expected to begin after the release of MediaWiki 1.19, possibly in May." Basically, the template system started turning into an ugly programming language. There was debate over using Javascript or Lua; Lua ultimately won due to implementation concerns. The mailing list threads announcing the decision and discussing the change have further details.

Re:Stop delaying the inevitable.

[dkf]

"the template system started turning into an ugly programming language" - ah, any sufficiently complex system eventually evolves to contain a limited, broken version of Common Lisp.

This includes Common Lisp, which contains itself as a proper subset.

Re:Lua

[Anonymous Coward]

I've never been able to get into Lua, whereas Python and Javascript I have. I prefer C/C++, Java, C# however. Though, if I had to pick a scripting language to use I'd use Python. Ruby is unbearable for me, I've tried to like it just can't. Lua isn't unbearable so much as I'm generally too bored with it to try it.

Things I generally don't like about Lua:
1) Lua replaced the ! symbol with ~ for Not. This doesn't make any sense. Not that ! made much sense either. I do like that they added a "not" keyword. That at least makes sense.
2) It feels very BASIC with its do, end, then, end etc. That's not a good thing. We should be moving away from that garbage.
3) I'm not a particular fan of any language that wants me to type one of; local, let, or var. The parser should be able to figure out when I'm assigning at all times. And, they still use == in this language which is silly since the whole point of using local, let, or var is so you can distinguish = from assignment or condition. It's annoying when languages that do this. Having said that, you could just pull a Pascal instead := or something if you absolutely must avoid ==, I'd complain a lot less. At least it's a clever and convenient way of addressing the problem. Let's face it, == only makes sense to a programmer, a mathematician would look at you weird. Then again they'd look sideways at := too, whereas Let in math has a meaning. Really I think math should teach := and drop the let, it'll save room on whiteboards.
4) Why should you have to prepend = to evaluate something? Like: = 2+3, or even = 3 == 3. Why can't I just type 2+3, or even 3 == 3? It's weird.
5) They went so different with everything, but they kept % for modulo? Doesn't make sense, why not just type mod? The symbol never made much sense. If they were being really adventurous they would have tried harder IMHO. Having said that, I respect that they switched ^ to power instead of xor.
6) I'm not a fan of using .. to concatenate strings either. "a".."bc" looks godawful goofy. I much prefer "a" + "bc". I get that it can cause problems when you need to mix in math, but that's what parenthesis are for. I see why they didn't use + though, they support "coercion", like 100 + "7" becomes a 107 integer. Which is a pretty cool concept I guess. But, it forces you do something weird like .. for concatenation which is a minus against it. Maybe they could have done just "a" "bc" becomes "abc". Then it'd be as simple as two strings like str1, str2 just being placed like... str1 str2 in order to concatenate them. Then they could still use + for coercion.
7) I don't mind nil for NULL. It's better than Python's Nothing IMO because it's shorter. Though, I see where Python was going, they were trying to make it obvious when read by a user who doesn't know programming. However, the rest of Python isn't obvious to a non-programmer anyways, so that defeats the purpose. Whereas, nil is at least is less typing, doesn't require an uppercase, and it has an English and Latin definition so as far as being a real word it's wins against Nothing in at least simplicity. I give them props for using this.
8) tonumber("10") is goofy, they're going for English I guess. Python's int("10") is less typing so I'd prefer that. I think when it comes to English vs typing less, as long as it isn't a weird symbol that makes no sense, I lean towards typing less. However, I could live with tonumber, it's not one of the worst things in this language.
9) Having to type function or def in a language to declare a method is annoying. If I was forced at gunpoint to choose, I'd probably go with function because at least it's obvious, less typing didn't win out here, def is weird looking and doesn't make sense at all. The def keyword reminds me of Sub from BASIC, in a bad way. I realize it's a bastardization of defmethod from Lisp. If we absolutely have to have some way of parsing methods (I think there should be a way around it IMO) startin

Re:Raw- or OOP-base Lua?

[nahdude812]

There is a LUA PHP PECL extension: http://pecl.php.net/package/lua [php.net]

It's relatively new, but this kind of attention could really skyrocket the extension forward. It's a great idea at large, there are a variety of situations where you want to defer decisions to your customer. Historically that meant creating a kind of pseudo DSL with a bunch of forms to fill out for the customer, with hopefully most major options covered, but usually failing to satisfy a variety of corner cases.

Another alternative is the V8JS extension (JavaScript). The advantage of JS is that more people know it already, and in may ways, JS is surprisingly elegant (not that Lua isn't). It won't perform as well as LUA though, and requires more resources to maintain the VM.

Re:Not a language problem

[David Gerard]

That's the precise problem. 1. the language was never designed, it accreted, and is mathematlcally impossible to describe fully in most sensible formats. 2. we can't throw it away because there's billions of words of text in it accumulated over ten years. 3. we can't throw it away because the existing editor base demand it stay because they're used to it.

So WMF is (a) throwing money as well as brilliance at the problem, and (b) has put Brion Vibber onto sorting out what is to be removed from wikitext, because he's one of two people (Tim Starling the other) that people will accept the opinion of on this matter. All proceeds well :-)

So now the problems are with seriously complicated things like doing bidirectional text [mediawiki.org] properly - a hard requirement for an international project, and one that is not done quite properly by anyone else. Something where mere dev brilliance has half a chance :-)