mruby

14 years ago (github.com)

Could anyone explain to me what the difference with normal ruby is?

"Lightweight", does that mean:

    Small but slow?
    Big but fast?
    Quite small and quite fast, but with a half-assed library?
    Big, slow, but low RAM usage?

I understand from another comment that this is intended for embedded systems. Does that mean running it on a microcontroller without OS? Cause the moment you can flash Linux, you can use Ruby MRI, no?

  • Yes, it would be nice to know what tradeoffs mruby makes and how they differ from the ones made by other ruby implementations

  • >I understand from another comment that this is intended for embedded systems.

    Nope, he said embedding. He means things like Lua where you have a scripting language embedded in a program that is running on a faster lnaguage. Common in video game dev.

    >Does that mean running it on a microcontroller without OS?

    Nope, not necessarily. It being portable means it's plausible but it's an unlikely usage scenario. More likely, it means being able to use it across a variety of POSIX derivatives.

    >Cause the moment you can flash Linux, you can use Ruby MRI, no?

    Also not true. What a micro-distribution of Linux can run on is not necessarily something MRI Ruby can also run on.

I've been waiting this for a long time. There's also TinyRB (http://code.macournoyer.com/tinyrb/) but it's too small subset of ruby to be useful and seems abandoned.

But my first impressions are not very positive (stripped x86_64 executables with -Os):

  -rwxr-xr-x 1 user group 708480 Apr 20 11:27 mrbc
  -rwxr-xr-x 1 user group 713056 Apr 20 11:27 mruby
  -rwxr-xr-x 1 user group 712128 Apr 20 11:27 mrubysample

compared to lua-5.2.0:

  -rwxr-xr-x 1 user group 147864 Apr 20 11:28 lua
  -rwxr-xr-x 1 user group  99168 Apr 20 11:28 luac

I'm not a big fan of lua as a language but it has been the only option to do scripting on small embedded systems. I've manged to compile size-optimized version of lua on arm to the size of about 80kb but mruby just might be too big for my embedded usage.

  • Honestly, I'm pretty impressed it's only 7-10 times the size. Ruby is a comparatively huge language, and the compiled size will more likely get smaller than larger from here.

  • Lua "cheats" by leaving out regular expressions and including a lightweight (but still powerful) matching facility.

    • Plus, no unicode support. This needs lots of code to support properly. Does mruby include it?

  • Why aren't you a fan of lua? From what I've seen, it looks great.

    • Just a quick list of annoying things:

        - comments start with --
        - no bitwise operations in language
        - default numeric data type is floating-point. it's possible to change it to
          integer but it raises uncertainty with compatibility of external libraries
        - OOP in lua is quite programmer-specific: everyone seems to have their own
          best practises
      

      Of course lua has good features too, like coroutines and good C API. Squirrel (http://squirrel-lang.org/) also seems like a nicer alternative to lua but it requires a C++ compiler.

      IMHO lua's best asset is the small and fast VM. I wish there would be other good, modern languages that target it.

      11 replies →

I am seeing this sort of thing frequently in GitHub - people start working on something and it gets "released" before they are ready with it and the authors have to scramble to say that this is not ready, ward off degrading comments etc.

The js.js blog post mentions this and in mrbuy , the README has just been updated. Is social coding being taken to the extreme?

  • Why don't they use something like bitbucket (free private repos) until it is ready to be launched?

    • I seriously doubt that whether the repositories were private was a financial consideration. More likely, they wanted others to be able to find the project and join in.

      People who develop software of this caliber can easily afford the expense of a private Github repository if they want one.

>mRuby is the light-weighted implementation of ruby language complied with ISO standard to execute various environment. It can run as 'interpreter form' or 'compile and execute on vm form' according to its module construction.

Can anyone tell me how it's different from other ruby implementations? What does 'execute various environment' mean? Can I run it inside JVM like JRuby?

When I visit http://www.mruby.org Google translate tells me, "This domain has been captured by. Com name."

As an aside, this sent me on a little adventure to http://www.mruby.com which is ... quite a treat.

  • The domain registrar is basically "Name.com" in Japanese. Google translate often fails hard on Japanese to English.

  • matz own mruby.org. and its page is under construction. matz said I pushed source code only, I'll build web site and docs later.

  • www.mruby.com

    Matt Ruby, Comedian, writer, and 37signals’ first employee.

    Probably not a coincidence.

Great job, i have been wondering ruby as an embedding/portable small language for a long time.

I am a big Ruby fan but I don't really see how this is enough of an improvement over Lua to pose a serious threat.

  • Depends on the audience. There are probably lots of people who know Ruby and would like to be able to use it where they currently can't. It might not be likely to win the hearts of the C++ game engine hackers, but that might not necessarily be the goal.

  • I thought the hivemind was that Lua was bloody awful?

    Disclaimer: I have never even read some Lua, honest question

    • It's not elegant but it's incredibly compact and isolated. I embedded it as a language in an iPhone game (as have many others). Making it bridge with Objective-C was fairly straight-forward and the memory/speed footprint was acceptable for a mobile device.

      3 replies →

    • I've only dabbled a bit in Lua but I mostly read very positive things about it and there are tons of success stories of embedded Lua out there. Way more than any other embedded scripting language. Unlike Ruby or Python etc Lua was designed from the ground up for this.

    • As others have said, it is small, fast and flexible with a very permissive licence so it is the scripting language of choice for embedded and gaming applications.