How Compatible is GNU Smalltalk with Squeak - smalltalk

I'm working on an app in squeak that requires no graphics at all, its all just data manipulation. The problem is that I work in a fairly conservative environment and I dont think I'll be able to sell a squeak app to my managers (I feel like the bright colors, round interface and general "what-the-heck-is-that" feel of squeak will scare them off). So I'm considering running the app under GNU Smalltalk, as a more "traditional" command-line interface is less likely to scare off stakeholders.
So, can anyone either provide, or point me towards, a list or set of what features/classes are or are not compatible between Squeak and Gnu Smalltalk. In other words, how hard will it be to port an app from one to the other (again assuming that its non-graphical, so no need to worry about morphic)?
Thanks!

I agree 100% with igouy; in addition to that, the main difference will be the filesystem classes. GNU Smalltalk's are more similar to what you get with Squeak's Rio package.
You can convert your code from Squeak to GST with gst-convert which will also take care of some of the difference.

There is an ANSI Smalltalk Standard (http://www.smalltalk.org/versions/ANSIStandardSmalltalk.html). Gnu seems to be a full implementation of the standard (see Gnu Wiki) and Squeak seems to be fairly compliant (see Squeak Wiki). So stick to the standard and you should do well.

The GST implementation will give you a much better answer than we can - so just try it - file out your code, and see what fails with GST.
I don't know how up-to-date the Rosetta "Cross-Dialect Smalltalk Code Interchange Tool" is but it might help.
Here are some minor differences that were leveled out to make things easier on the benchmarks game - GNU Smalltalk :: Squeak
When you hit specific problems ask about them on the GNU Smalltalk Mailing List.

In addition to the other suggestions, make sure your SUnit test cases are up-to-date; it's much easier to find any missing methods in GNU Smalltalk that your application is using that way.

Pharo looks more professional, and might help. Or if you have less than 4GB of data, Gemstone. A Seaside user interface looks the same as a ASP.NET MVC or Rails one, and can be created easier.

Related

Compiling Objective-C app for Linux (API coverage)

I might be asking something strange here, but I'm unsure where to begin. The thing is that I am considering writing a command line tool on a Mac using Obj-C and the Foundation classes.
But there is a very big risk that I would like to be able to compile it for different Linux distributions to run as a server app in the future.
I understand that it is not a problem in itself to compile Objective-C for Linux, but what I don't understand is the API coverage.
As I have understood it so far I can use GNUStep to compile for linux, but is there a good way for me to get an overview of the API coverage? What I mean is, if I use a class that has been added to the Foundation framework in OSX Lion lets say, how big is the risk of that not being available in GNUStep at that time?
I hope I am asking a question that you guys can understand, basically I want to avoid writing an app that can theoretically be compiled for linux, but not in practice because of missing classes etc.
Thanks!
An opinion: The risk is fairly high. GNU Step is an open source project and dependant on its volunteers to keep it up to date. OS X Lion has a small number of additions to Foundation and AppKit.
Your best option if you want it for *nix in the future will be to write it in generic C/C++ and then thinly wrap it in an NSTask if you want a GUI.
You should be able to check if the API's you're using are available by consulting the GNUStep base API docs.
You may want to target GNUStep as your base if compatibillity is a big concern. Compiling for mac should then be rather trivial, compared to moving the code the other way. Of course you always have the option of helping inplement whatever is missing from GNUStep too.

Decompiling Objective-C libraries

I've just finished a library in Objective-C that I compiled as a Static Library for distribution.
I'd wanted to know what chances to get this decompiled are out there.
Do you know any software that can do this?
If so, how could I protect me better?
EDIT: My static lib is made for iPhone / ARM
I created an algorithm that depending on the some parameters of the app, it can run as demo or as full code. You init the object with X variables and unlock the full version. I was wondering if they'll be able to see this algorithm so they can create a key generator.
If it executes, it can be decompiled. Objective-C is particularly easy to decompile into readable code thanks to its dynamic features. If you want to make things a little bit harder, you could write most of your code in plain C and strip the executable — which of course has the tradeoff of making your application design harder to manage. But be honest with yourself: If somebody wants to crack your code, you are not going to be able to stop them. Crackers have practically unlimited amounts of time and enthusiasm and will actually be excited by any novel efforts you put in to stop them. Nobody has yet made uncrackable software, and the biggest corporations in the world have tried. You're not going to do better than them, especially if you need to ask about it on Stack Overflow.
Take the time that you would have put into thwarting decompilation and use it to make your product better — that will have a much better ROI.
It's not clear what you are trying to protect yourself from. Yes, it can be reverse engineered. The simplest tool is otool, part of the standard developer distribution:
otool -tV <library>
From that they run up to things like IDA Pro, which has iPhone support and is very nice for this kind of work. In between, I'm really surprised that I haven't seen a rework of otx for iPhone/ARM yet. I wouldn't be surprised to see one show up eventually. And of course there's gdb if you're trying to work out how things flow and what the data is at various points.
If you have more details about what you're trying to protect yourself from, there may be some targeted answers. Beyond that, read Chuck's comments.
ChanceGetsDecompiled = ExpectedGainFromBeingDecompiled / PopularityOfLibrary
Well if you REALLY want to know I would try decompiling it your self. You don't say if this is for PPC, Intel, or ARM which makes a difference. Here is a decompiler for Intel
i386 Decompiler
I don't know what you could do (I don't think there is much) to limit this. Code can always be reverse engineered. Be happy that your not using java or .net. Their decompilation is so nice.

Programming features missing in C++ and Java

What are the programming features that are missing in C++ and Java ?
For eg. You can't do recursive programming in QBasic ? You can't dynamically allocate memory in QBasic.
What would be the good to have features in C++, Java.
I think Lisp Programmers will be able to add a few.
I miss lambda expressions.
This answer deals only with C++
Things I miss from the syntax, or the standard library:
RegExp as part of the standard library
Threads as part of the standard library
Pointer to member methods (not objects!)
Properties would be nice (I have seen codes that emulate this via C++ preprocessor... note an nice looking code).
Some lower level networking API (sockets!), and higher level API (give me this file from this ftp, submit "this" to this site via POST).
This is the list of things I would like to see, but I assume other people will disagree with me.
Memory garbage collector is nice.
A n interface for a GUI toolkit - let MSVC map it to win32, and on Linux... (good question!)
A stable ABI. In C it's a standard - but on C++ we are still missing a few decades. I want also stable ABI between compilers - I want to compile one library in MinGW, the other with CL and all should work.
This is the list of things I want to see, but I know they will not get away:
Compatibility with C. Really, it's a myth right now. using namespace std killed it.
Include, headers. Most of the information is already available in the DLL/so/a/"library", do we really need to keep this bad decision from 30 years ago? If needed the compilers should keep information in the binaries.
The need for Makefiles - the compiler should be smart enough to know what to do with this code, from the code itself. Pascal is doing it quite good. I think also D.
(I might be wrong, please correct me) The official standard openly and freely available for viewing. Why should I pay for the official papers? Do I need to do it for HTTP? UTF8? Unicode?
I think this is a very subjective question. From a theoretical point of view there's nothing "missing" in Java because you can do everything you want to from the perspective of the outcome as an application.
As with QBasic - recursion may not be possible but that doesn't prevent you from changing your recursive algorithm to an iterative algorithm. Programming language theory tells us that you can do this with every recursive problem. So there's also nothing missing here.
I think what you mean are features that are "nice to have" - and here everyone has to decide for himself. I'd even say there are features in the language which would have been "nice not to have" such as static imports - but again this is my subjective opinion...

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).