Why Lua?

#1

Post by tlowrimore » Tue, Jan 31, 2012, 7:22 PM UTC

Why Lua?
blog.datamules.com

Re: Why Lua?

#2

Post by alanfalcon » Tue, Jan 31, 2012, 9:24 PM UTC

I took some Visual Basic programming courses in high school, some PASCAL courses in college, and then didn't program anything other than basic HTML/CSS for the next eight years. Last year I programmed an iPhone game in Lua (using the Corona SDK) and it was easy as Tau. Sure a better programmer would have finished the programming aspects in a quarter the time it took me, but I started by looking at Objective-C and I'm not sure I ever would have picked it up without some kind of formal training. Contrast with Corona/Lua, where I watched a few eight minute videos on YouTube and could turn around and make simple but complete programs, and more importantly completely understand what was going on within them. Reading the Lua documentation was a revelation, reading Apple's was a headache.

Why Lua? http://itunes.apple.com/us/app/beat-boxes/id460798042

Re: Why Lua?

#3

Post by hythloday » Tue, Jan 31, 2012, 9:34 PM UTC

I love Lua, but when I read statements like this:

>>> In Python, you might __import__('...')' some module and then the variables of the return value would be accessed like vars(module)

it makes me wonder if the author is just unfamiliar with Python (and by extension, any language other than Lua) or if they're deliberately misrepresenting other languages to make Lua look good (which it definitely doesn't need).

Re: Why Lua?

#4

Post by groovy2shoes » Tue, Jan 31, 2012, 9:45 PM UTC

Good article, but one nitpick: not everything in Lua is a table. Tables are a versatile data structure that can be used as arrays, dictionaries, objects, etc. However, Lua provides many types besides tables: numbers, booleans, closures (functions), strings (which are interned), coroutines, and something called userdata (which are typically pointers to something implemented in C).

Another cool thing about Lua, which was mentioned only briefly in the article, is proper tail-call optimization (TCO) like you'd find in Scheme. TCO makes expressing recursive algorithms nicer because you don't have to worry about blowing your stack.

Lua's design philosophy -- giving the programmer a handful of basic yet powerful features -- makes it somewhat Schemy. I suspect that Lua is about as close as you can get to a ball of mud before becoming Lisp.

Re: Why Lua?

#5

Post by simon » Tue, Jan 31, 2012, 9:53 PM UTC

The article seemed a little short for me, but then I am actively trying to select between Lua and TCL for some personal scripting projects. There are many fine features with each language and few downsides, so the selection process is hard. Of course, that's a nice problem to have.

TCL is ahead by a nose at this point with Unicode support baked in (vs. using a library) and file system handling built in (again vs. using a library).

Re: Why Lua?

#6

Post by chubot » Tue, Jan 31, 2012, 9:55 PM UTC

Why isn't Lua more widely used? One reason is a consequence of it being an embedded language. Lua has had 5 major versions which are very incompatible with each other. You're just supposed to stick with the previous version until you upgrade your code.

I read all the Lua papers, and they are quite fond of "getting it right" (which is refreshing). They will break things to get it right, whereas other languages stick with all their old design warts in the name of compatibility. I like this approach, but it comes at the expense of popularity.

Compare Lua with Python, which has had basically 1 major version for 20 years Python 1.x are all compatible with 2.x -- that was a license change; and Python 3 is having adoption troubles which proves the same point. Python 3 was the chance to "get things right", or fix old design warts, but you can see what a big impact it's having on adoption, fragmentation of libraries, etc.

The other reason is that embedding a language isn't as common a use case as a scripting language. I've tried to write stuff in Lua rather than Python, but really Python's "batteries included" philosophy just kills any advantage Lua has.

The main reason I would like Lua is so you can distribute stable (small) executables... but when you're starting out Python is a lot easier. You don't want to download LuaSocket or whatever and mess with the build system.

Re: Why Lua?

#7

Post by gregholmberg » Tue, Jan 31, 2012, 9:56 PM UTC

Speed& Simplicity

LuaJIT speeds can rival code written in C. And if you are still not getting the speed you want, see my 1st point above (Integration with C and C++ for that matter).

The simplicity of Lua is, I think, really underrated.

It is a good learning exercise to write some small benchmark / utility / tool in Lua so you can get an idea of how quickly you can develop, and how fast the resulting code will be.

Then read through the Lua source [0] to see just how little code is required to give you that platform for your ideas.

[0] http://www.lua.org/source/5.1/lua.c.html

Re: Why Lua?

#8

Post by meric » Tue, Jan 31, 2012, 10:00 PM UTC

In lua, the metatable is the killer feature that python doesn't have.

Re: Why Lua?

#9

Post by ammmir » Tue, Jan 31, 2012, 10:08 PM UTC

lua (the language and core libraries) is stable and small. many developers are attracted to node.js or rails due to the community ("look, everyone else is doing it!"), ecosystem (abundance of modules/gems to choose from), and rapid release cycles.

lua seems to have more of a relaxed, niche community among game developers and scripting language embedders.

i've been using lua for about a week so far, for a music player i'm building (http://cloudplay.fm/) and i'm writing the song search/ranking system in lua. it's wonderful to be able to prototype it outside the application and not have to deal with the integration until you need to.

i would consider using lua on the server-side (see http://luvit.io/ for a node.js-style interpretation, although i'd prefer coroutines instead of callbacks) but there needs to be more work on the library front.

to help lua grow, i'd fix these things:

- add unicode support

- bring the CLI up to par with node.js (i use node as a calculator, too)

- build a modern distribution that includes frequently used luarocks

Re: Why Lua?

#10

Post by groovy2shoes » Tue, Jan 31, 2012, 10:13 PM UTC

simon wrote: post #5

The article seemed a little short for me, but then I am actively trying to select between Lua and TCL for some personal scripting projects. There are many fine features with each language and few downsides, so the selection process is hard. Of course, that's a nice problem to have. TCL is ahead by a nose at this point with Unicode support baked in (vs. using a library) and file system handling built in (again vs. usi…

Tcl is an interesting little language as well, and the niche it was created for is similar to the one Lua was created for. The biggest advantages that Lua has over Tcl, off the top of my head, are speed and lambdas. Tcl's semantics make it very hard to optimize because it is stringly typed (with some bytecode and value specialization in the background, but with conversions between strings and other values as needed).

Tcl's file system interface is definitely an advantage if you're trying to avoid third party libraries. However, depending on what you need to do with Unicode strings, Lua's strings are "8-bit clean" and have no difficulty storing Unicode characters; Lua's string functions (the pattern-matching functions in particular) aren't Unicode aware.