Anyone using Scheme/LISP for embedded projects? - embedded

This question is maybe somehow inspired with Anyone using Python for embedded projects?; so anyone using some Scheme version or Common Lisp (like ECL) for free/oss/commercial projects?
Personally, I used (and still using) TinyScheme for personal projects where some embedded language is needed, mostly due extremely easy embedding (sorry Python lovers, been there and that is quite painful, especially after I learned from TinyScheme how things can be simple).

The most prominent project I remember hearing about is (Gambit) Scheme on the iPhone. It was shut down by the user agreement for a while but I suppose with the new one, this kind of development is allowed again.
I don't see it on the page any more, but I remember a related blog post about interactive development on the iPhone using Scheme. Very exciting.

Related

Ironpython questions

I have a few questions that I hope clarity and facts can be fed all of us about this. First, the last release of ironpython had the feature of running on the mobile platform highlighting that on mono/android it runs best and not so much on the other platforms which are IOS and Windows phone. So does this mean one doesn't have to use the SL4A? Can i argue that monodroid hooks into the core of what android is capable of and so might give a more robust access/implementation/rendition of apps on android?
Next, I just want to be sure of this: As with python you can create full fledged desktop applications with ironpython right? Cos everywhere (almost) I see ironpython they refer to it as a scripting tool and how you can script aspects of excel etc which has prompted me ask such a question. some say that the speed of applications written using ironpython is not that great and I was arguing asking for why that opinion is held by those who were speaking and no one could say anything worthwhile.
Lastly, with the movement at novell and xamarin, I have not understood where mono stands in their release schemes. I have a mac and I installed a recent version of mono and when I typed ipy I saw something like mono 1.1.0 or something like that. Does anyone have a clue of what is going on with it.
I fell in love with python from learning ironpython and I think the ironpython concept is just sheer brilliance its a pity microsoft esteemed F# other it.
First off, for future reference, multiple questions should really be, well, multiple questions. :)
On IronPython for Android: it works slightly better than on other platforms (where it doesn't work at all right now) but it's still very, very early code. There are some limitations with what you'll be able to do (mainly, you cannot inherit from Java classes from dynamic code). It's very experimental.
On desktop apps: You can absolutely write full apps in IronPython. There are some samples that show how it can be done. In particular, PyWpfSample and PyGtkSample. Startup times are not great, but the actual runtime should be just fine for most GUI apps.

How to create an online rebol console?

Where can I find the code for creating an online rebol console like the one here ?
http://tryrebol.esperconsultancy.nl/
Update: for the sandbox system on the server, can't Rebol manage it itself with some security wrapper and its security options ?
As for console itself, I don't know Ruby so I don't want to use TryRuby and why would I need it ? Can't I mimic Rebol console itself by "remoting" it somehow ? Why RT or Esper Consultancy can't make an opensource version ? There's no value in keeping it closed source. Rebol needs to prove it's more open than in the past.
In my opinion, you should aim higher with something like the already open-sourced Try Ruby. You'd type in expressions and it would guide you. Their showcase site is at tryruby.org and is fairly slick.
I modified TryRuby to work with Rebol and it wound up looking like this:
But I'm not going to run it on my server because I didn't want to belabor the necessary sandboxing/etc. or protections against someone running an infinite loop. I can give you what I've got so far if you want it.
I started a tutorial script here that no one seemed interested in helping me with, so I wandered off to other tasks:
http://www.rebol.net/wiki/Interactive_tutorial_script
I'm not sure what exactly you want. You mention you want a remote REBOL shell instead of a tutoring setup, but that's what the Try REBOL site is. There are several reasons it's not open source:
It's in heavy development. I'm currently changing the code regularly.
So it's not in a release state. Preparing it for release, documenting and publishing it would take a lot of extra work, as with most projects.
It's written in my CMS that's also in heavy development. Even if the Try REBOL site were open source, it wouldn't run. The CMS is not planned to be open sourced soon.
It's not meant as a generic REBOL remoting tool, but as a one-off demo site. If that site is running, what's the use of more of them?
As others have answered, there are many generic solutions for remoting that you could use. Also, most parts of the Try REBOL site are readily available as open source:
Syllable Server, produced and published by us.
The Cheyenne web server.
The HTML source of the web client can be viewed, including my simple JavaScript command service bus.
Syllable Server is an essential part of the site, as the sandboxing is not done with REBOL facilities (except some extra limits in the R3 backend), but with standard Linux facilities.
A truly air tight (do I mean silica tight?) sandbox is close to impossible with R2.
R3 (still in alpha) is looking a lot more promising. The deep technical discussions in flight right now (see Cure code and AltME/REBOL3 Proposals regarding unwinds and protect and even occasionally mentioning sandboxes should lead to an excellent sandbox capability.
Right now, the big advance R3 has that makes Kaj's tryREBOL possible is R3's secure policy settings which make it possible (with some careful wrapper code) to construct an alpha/demo sandbox.
To answer your precise question("where can I find code...", you could try asking Kaj for his :)
I'm new to StackOverflow. I'm not sure if this is going to end up as a reply to your comment, or as a new answer.
The somewhat common idea that any project can be open sourced and contributed to by others is a naive view. In the case of my Try REBOL site, it makes no sense. It's not just in heavy development; it's written in a CMS that's also in heavy development. Basically noone could contribute to it at this point, because I'm the only one who knows my CMS. Or in any case its newest features, which I develop by developing Try REBOL, and other example sites. So developing Try REBOL means developing the CMS at the same time, and by definition, I'm the only one who can do that.
More generally, my projects are bleeding edge, innovative technology with a strong vision. The vision is mine, and to teach it to others, I have to build it to show how I intended it to work. So there's a catch 22: to enable others to contribute, I have to finish my projects first, because people typically don't understand them until I show them how they work.
There certainly are other projects where mass contribution makes more sense. Still, only the top projects get the contributors. We found that out the hard way. We created Syllable Desktop and Syllable Server with surrounding infrastructure for contributions. These are fairly classic, well understood operating systems that many people could work on in parallel. However, despite years of begging, we get very few contributions.
So, if you feel a burning need to contribute to our projects, please pick one of the many tasks in Syllable to execute. :-)

Qt4.5 vs Cocoa for native Mac UI

I've been developing for Windows and *nix platforms for quite some time, and am looking to move into Mac development. I am tossing up between using ObjC/Cocoa and C++/Qt4.5.
The C++/moc semantics make more sense to me, and improving knowledge in Qt seems like a sensible thing to do given that you end up with a skill set that covers more platforms.
Am I likely to handicap my applications by skipping Cocoa?
The sample Qt applications look pretty Mac-native to me, but they are quite simple so potentially don't tell the whole story. Are there other pros to the Xcode way that Qt doesn't have, such as packaging, deployment, etc.?
Here's an easy way to answer it:
If you were developing a Windows app with .NET or MFC, would you handicap your applications by using Qt? If the answer to that is yes, then the situation is likely to be the same on the Mac.
A few negatives I can think of off the top of my head:
Licensing
Qt apps, while good, are not completely a native UI experience and there's things a native UI designer can do in Cocoa which boggle the mind. While I can't be sure that all the same functionality isn't available in Qt, I doubt it.
Qt is always a little behind. If Microsoft or Apple come out with a great new technology, you have to wait for the Qt developers to update Qt.
However, with all that said, only you can determine the business value of using Qt. If you think cross-platform development is going to be a major part of your development, then Qt might be worth it, despite the issues mentioned.
Ask yourself: how many of the best Mac applications that you know of use Qt instead of native Cocoa?
For our robotic systems, we originally wrote our control software in C++ using the cross-platform wxWidgets library (we avoided Qt due to some licensing concerns), because we felt that we had to target Windows, Linux, and Mac platforms for our end users. This is what we shipped for over a year until I started tinkering with Cocoa.
Right away, the thing that most impressed me was how quickly you could develop using Cocoa. Eventually, we decided to drop support for Linux and Windows and rewrite our entire control applications in Cocoa. What had taken us years to put together in C++ required only three months to completely reimplement in Cocoa.
Aside from the "lowest common denominator" interface issues that others have pointed out, the rapid development allowed by Cocoa has become a competitive advantage for our company. Our software has advanced far more quickly since our conversion to Cocoa, and it has allowed us as a new company with one developer to pull even with 10-year-old competitors that have 20-man development teams. This appears to be a common story in the Mac development space, where you see a lot of small teams who are able to create products that compete with those of much larger companies.
As a final note, using Cocoa gives you the ability to stay on top of the new APIs Apple is continually rolling out. We're now working on a new control interface that will make heavy use of Core Animation, something that would be painful to deal with using Qt.
I'm currently developing both with QT (actually PyQT, but it makes no difference to your question) and native Cocoa app. For me it's no brainer, I'd chose Cocoa. It's really worth time to explore Cocoa in general, there are many great concepts within the Cocoa framework, and Objective-C 2.0 as well.
I'd use Qt if you want this to be a crossplatform application.
You can have a look at the QMacCocoaViewContainer class. It acts as some kind of wrapper for generic Cocoa views, so you can also have Cocoa elements which are not officially supported by Qt.
Of course this means learning a little about Cocoa and Objective C and how a Cocoa UI would need to look like. But if you already know Qt well and if it’s not like your application is all and only about the GUI this could be a good way to go.
And don’t forget about the QMacStyle::WidgetSizePolicy or you won’t understand why your tables come out so huge.
Obviously, the best option is to use a cross platform suite that supports native widgets.
With QT4 you can build your base user interface. Then just add native support for your specific target platform.
Sure, Cocoa has a lot of fancy stuff (and you can still use them trough QT4), but let me be clear. I see a lot of fancy Apps on the AppStore, pretty ones, but most of then are just crap, expensive.. what ever. I really missed my Kate text editor, my okular viewer, my krita drawing software... those are just better than the commercial and expensive alternatives and are free. so i just tweak the source code a little bit too have a REAL native and great experience.
What if i have to use a linux app on my main computer with is a mac os x? or windows? or whatever? only?
For example, why on earth i have to buy a expensive ,fancy but far less featured image editor software for my mac like pixelmator when i can use a full featured real image manipulation software like Gimp? YES Gimp is gtk2 based which is a pain on any platform, specially on Mac because is really ugly. Gimp should be ported to QT4. Inkscape should be ported to QT4 too, and it would feel so great.
Is so simple to do.. gosh!
http://doc.qt.nokia.com/4.7-snapshot/demos-macmainwindow.html
Even you can add support for the the new native lion fullscreen feature, unified title and toolbar menus, etc
I , as a user, i really care about efficient, featured, good and cross platform apps, i don't really care about developer's convenience or laziness .
I do a lot of cross-platform development (Mac, Windows, Linux), and for some projects use Qt. It is a fine framework, and provides a rich class library. If you need to deploy on multiple platforms, cannot afford to spend the time/effort on platform-specific front-ends, or the "generic" support for each platform is sufficiently good, then use Qt.
However, Qt inevitably suffers in some ways from the lowest common denominator syndrome, and sometimes does not feel quite native enough. There are also certain features that are either difficult to support, or are simply not provided in the Qt libraries. So if you can afford the time and effort, or your app really demands the attention to detail and fit & finish, then developing separate front-ends may be worth it.
In either case, you ought to be writing your back-end (aka domain) code in a platform-neutral and front-end neutral manner. This way, the front-end is easily replaced, or modified between platforms.
You could always start with a Qt front-end and go for a quick time to market, then develop a native front-end down the line.
In practice, I've noticed that a Qt app on Windows looks most "native", while on Mac there are certain subtle telltale signs that make it look/feel not quite right. And Mac users tend to have much higher expectations when it comes to UI/UX!
Since posting this, i've been learning the Cocoa / Objective-C way, and have been quite impressed. Despite what I initially thought was quite a quirky syntax, Objc appears to be a very effective language for implementing UI code, and the XCode sugar - things like Core Data and bindings - make short work of all of the boring bits.
I spent a while with the QT examples and documentation before digging into cocoa, and tend to agree with what has been said above w.r.t being slightly behind the curve and less 'aqua-ish' - albeit from a fairly trivial inspection. If I absolutely had to be build a cross-platform app i'd probably use QT rather than trying to separate out the UI code, as it seems like it would provide close-enough visuals, but for mac only purposes, Cocoa seems like a definite win.
Thanks all for your responses, they've all been very helpful!
DO NOT use Qt for a Mac app. You will get no hardware acceleration for 2D rendering, and you will not be able to deliver ADA compliance.
Depending on what kind of apps you want to write, another contender is REALbasic now called Xojo.
The move from C++ is pretty easy (I have 15 years C++ experience) and the framework and IDE extremely productive. You have the added bonus of being able to deploy to Linux and Windows with trivial effort. Their framework compiles to native code and uses native widgets so you don't have an emulated look and feel.
The big reason for learning Cocoa and coding in Objective-C is if you want to hone your iPhone skills or are chasing a really fancy user experience. If you wanted to rival the cutting edge of WPF development then I'd recommend Cocoa.

Is there any Subtext IDE or equivalent Example-driven Visual Programming Language/Interface published on the Internet?

I'm really excited about this new and experimental language named Subtext. But it's author haven't released nothing about it besides some papers and videos. Should I clone it? There are similar alternatives?
UPDATE I'm looking for an example-driven VPL, not just a VPL.
As Edwards' says in his related work section, the Self programming language is very similar. It shares subtext's emphsis on directness, uniformity, and liveness, but doesn't emphasize a tabular format (Schematic tables).
A lot of of work went into the Solaris version:
http://research.sun.com/self/papers/papers.html
seems there's a Mac & linux version, not sure how mature it is:
http://selflanguage.org/
Here's a video demo'ing Self, where they emphasize directness, uniformity, and liveness:
http://www.smalltalk.org.br/movies/
When you say "any VPL", do you mean none at all, or not a run-of-the-mill one? From the wording of the title question, I'll assume the latter. Here're a couple with some serious programming theory behind them:
Morphic is/was a/the UI piece of Self, and is now ported to Squeak:
http://wiki.squeak.org/squeak/2139
Prograph was a way-cool system, but I don't know of an available version.
A bit further out there is Kahn's Toontalk, based on Pictorial Janus:
http://www.toontalk.com/
I am sure you are aware of VPL On Wikipedia that lists many different VPL languages. You have not supplied information on what you are trying to achieve but another site is Synopsis. This is a commercial product.
From their website:
Synopsis is a completely visual RAD tool for Windows that frees you from having to write textual code and learning unnecesary programming details. With Synopsis you can concentrate on creating software instead of wrestling with mundane and complex low-level development tasks.
The image below shows how this application looks:
(source: codemorphis.com)
Granted my knowledge on this subject is limited and I do follow this to see if something really powerful can be created. I did see a project on CodeProject or CodePlex that was written in C# that allowed VPL but I cant find that URL.
If I ever do find that application I will edit this post!
You haven't provided more information about features you expect from such a VPL environment, but I think that "Tersus" could be interesting thing to look at. There're many VPLs, but mainly they're targeted as educational tools or addition to particular technologies (i.e VPL for Microsoft Robotics Studio) to simplify common tasks programming. The "Tersus" is full blown application development platform. It's open source and free to download for many OSes.
http://www.tersus.com
Coherence — The Director’s Cut
The Coherence home page is up at http://coherence-lang.org. The submitted version of the paper is there, with a new intro and a surprise ending.
Coherence claims to be an experimental programming language, a continuation of Subtext using other means.
Intentional shipped, but they are still kind of alpha, with limited distribution and testing. You can make example driven DSLs, but I don't know if the environment itself works that way.
http://lambda-the-ultimate.org/node/3287
You could look at the work on eve that is happening too:
http://incidentalcomplexity.com/

Which environment, IDE or interpreter to put in practice Scheme?

I've been making my way through The Little Schemer and I was wondering what environment, IDE or interpreter would be best to use in order to test any of the Scheme code I jot down for myself.
Racket (formerly Dr Scheme) has a nice editor, several different Scheme dialects, an attempt at visual debugging, lots of libraries, and can run on most platforms. It even has some modes specifically geared around learning the language.
I would highly recommend both Chicken and Gauche for scheme.
PLT Scheme (DrScheme) is one of the best IDEs out there, especially for Scheme. The package you get when downloading it contains all you need for developing Scheme code - libraries, documentation, examples, and so on. Highly recommended.
If you just want to test your scheme code, I would recommend PLT Scheme. It offers a very complete environment, with debugger, help, etc., and works on most platforms.
But if you also want to get an idea of how the interpreter behind the scenes works, and have Visual Studio, I would recommend Tachy. It is a very lightweight scheme interpreter written in c#. It allows you to debug just your scheme code, or also step through the c# interpreter behind the scenes to see what is going on.
Just for the record I have to mention IronScheme.
IronScheme will aim to be a R6RS conforming Scheme implementation based on the Microsoft DLR.
Version 1.0 Beta 1 was just released. I think this should be good implementation for someone that is already using .NET framework.
EDIT
Current version is 1.0 RC 1 from Oct 23 2009
Google for the book's authors (Daniel Friedman and Matthias Felleisen). See whether either of them is involved with a popular, free, existing Scheme implementation.
It doesn't matter, as long as you subscribe to the mailing list(wiki/irc/online-community-site) for the associated community. It's probably worth taking a look at the list description and archives to be sure you are in the right one.
Most of these are friendly and welcoming to newcomers, so don't be afraid to ask.
It's also worth searching the archives of their mailing list(or FAQ or whatever they use) when you have a question - just in case it is a frequent question.
Good Luck!
Guile running under Geiser within Emacs provides a nice, lightweight implementation for doing the exercises. Racket will also run under Geiser and Emacs, though I personally prefer Guile and Chez Scheme a bit more.
Obviously installation of each will depend on your OS. I would recommend using Emacs version 24 and later since this allows you to use Melpa or Marmalade to install Geiser and other Emacs extensions.
The current version of Geiser also works quite nicely with Chicken Scheme, Chez Scheme, MIT Scheme and Chibi Scheme.
LispMe works on a Palm Pilot, take it anywhere, and scheme on the go. GREAT way to learn scheme.
I've used PLT as mentioned in some of the other posts and it works quite nicely. One that I have read about but have not used is Allegro Common LISP Express. I read a stellar review about their database app called Allegro Cache and found that they are heavy into LISP. Like I said, I don't know if it's any good, but it might be worth a try.
I am currently working through the Little Schemer as well and use Emacs as my environment, along Quack, which adds additional support and utilities for scheme-mode within Emacs.
If you are planning on experimenting with other Lisps (e.g. Common Lisp), Emacs has excellent support for those dialects as well (Emacs itself can be customized with its own dialect of Lisp, appropriately named Emacs Lisp).
As far as Scheme implementations go, I am currently using Petit Chez Scheme, which is an interpreted, freely distributable version of Chez Scheme (which uses a compiler and costs money to obtain a license).