Building a simple DSL in Haskell with C++ interop - c++

I'm designing a simple interpreted language for testing real-time embedded systems. The control flow is severely restricted to provide strong static guarantees on what the scripts will do + how long they will run. For example, you can only branch on constant conditionals or loop over fixed ranges.
There is a large existing codebase in C++ with relevant models and IO libs, so this language must be able to call into C++. The systems under test have hard timing requirements, so we can't tolerate much jitter in the test framework. Our past solution was a custom DSL embedded in the C++ runtime, but we ended up re-inventing too many wheels (parser, linter, interactive interpreter, etc..) to achieve the static guarantees we need.
Haskell's facilities for crafting embedded DSLs with these guarantees are extremely appealing to me, but I'm stuck in determining how to embed it into the soft real-time C++ runtime. Any ideas? Pointers to any libraries / existing projects would be greatly appreciated!

Sounds like the path of least resistance would be an EDSL that generates C++. This way, you don't have to worry about the potential mismatch between soft real-time and the GHC RTS.
You might look at how other EDSLs that generate PLs are implemented:
HJScript uses a free monad approach to embedding JS.
JMacro uses more of an external DSL approach but embedded via TH. Wouldn't be my choice.
Instead of generating strings of C++ code, it's nice to have a data structure. Unfortunately, there doesn't seem to be a package available for C++. However, you could take a look at language-c — perhaps extend that or build your own. You might even consider generating C and using the C to C++ interop provided by those languages.
I'd probably dissuade you from looking at the design of Cryptol or Cogent as these are fully-fledged programming languages (that you have indicated you are inclined to steer away from).

Related

Deciding on a language/framework for a modular OpenCV application

What's this about?
We have a C++ application dealing with image processing and computer vision on videos using OpenCV, we're going to rewrite it from scratch and need some help deciding what technologies to use. More specifically, I need help on how to choose the technology I'd use.
About the app
The app's functionality is divided in modules that are called in an order defined by a configuration XML file and can also be changed in runtime, but not in realtime (i.e. the application doesn't need to close, but the processing will start from scratch). These modules share data in a central datapool.
Why are we starting from scratch?
This application wasn't planned to be as dynamic as it currently strives to be, so it's grown to be a collection of buggy patches, macros and workarounds; it's now full of memory leaks, unnecessary QT dependencies, slow conversions between QT and OpenCV image formats and compilation and testing times have grown too much.
Language choice
The original code used C++, just because the guy who originally started the project only knew C++. This may be a good choice, because we need it to be as fast as possible, but there may be better choices to account for the dynamic nature of the application.
We're limited by the languages supported by OpenCV (C++, Java and Python mainly; although I've read there is also support for Ruby, Ch, C# and any JVM language)
What is needed
Speed: We're aiming for realtime tracking. This may rule out Python and Ruby.
Class Instantiation by name: Although our C++ macros and class registration system work, a language designed to be dynamic that has it's own runtime would be nice. Maybe Objective-C++, or Java.
What would be ideal
Module/Plugin/Extension/Component Framework: Why reinvent the wheel, using a good framework for this would let us focus on what's special about our app. There are many options here. Objective-C has it's NSBundles; C++ has libraries like Boost.Extension, Pluma, DynObj, FxEngine, etc; C has C-Pluff; I'd even say there are too many options.
Runtime class loading and reloading: From a developing point of view, it would be interesting to be able to compile and reload just one module. I've seen this done in via code injection in Objective-C and using Java's reflection.
What am I missing?
I have too many interesting options!
Here's where I need help, based on your experiences in modular app development, with this constraints, what kind of language/framework feature should I be looking for?
What question should I make myself about this project that would let me narrow my search?
Edit
I hadn't noticed that OpenCV had GPU bindings only for C++, so I'm stuck with it.
Now that the language is fixed, the search has narrowed a lot. I could use Objective-C++ to get the dynamism needed (Obj-C runtime + NSBundle from Cocoa/GnuStep/Cocotron), which sounds complicated; or C++ with a framework.
So I'll now narrow my question to:
Is using NSBundle in a crossplatform way with Objective-C++ easier than it sounds?
What C++ framework will provide me with hot-swappable modules?
The main reason for swapping modules in runtime is to be able to change code in a fast way, would Runtime-Compiled C++ be a better solution?
Meta: I did my research on how to ask a question like this, I hope it's acceptable.
"What question should I make myself about this project that would let me narrow my search?"
if you need gpu support(cuda/ocl), your only choice is c++.
you can safely discard C, as it won't be supported in the near future
have no fear of python, even if you need direct pixel access, that's all numpy arrays (running c-code again)
i'd be a bit sceptical of ruby, c# ch and the like, since those bindings are community based, and might not be up to date / maintained properly, while the java & python bindings are machine - generated from the c++ api, and are part of the official distribution.
If you're looking for portability and have large memory for disposal then you can go with Java.
The performance hit between C++ and Java is not that bad. For conversion between Mat and other image format I'm still not sure, coz it needs deep copy to perform that, so if your code can display the image in openCV native format then you can fasten the application
pro :
You can stop worrying about memory leak
The project is much more portable compared to C/C++(this can be wrong if you can avoid using primitive datatypes which size is non consistent and for example always use int*_t in C)
cons:
slower than C/C++
more memory and CPU clock needed
http://www.ibm.com/developerworks/java/library/j-jtp09275/index.html

Good cross platform functional language for library use in a C++ application?

What are my options in terms of a fast functional language for library use in a cross-platform Qt C++ application?
It seems almost all languages (functional or not) have some way of calling C/C++ code in an easy manner. I'd like to go the other way around - write an application in Qt using C++ for stateful business logic, GUIs and stuff but drop down and use a functional language for the core calculation library.
Which ones are easy to use in this manner? Can for instance OCaml code be compiled into a static library and then consumed by a C++ app?
Thanks,
Rickard
Haskell has this capability, though the interaction with Qt/qmake and your build process with ghc may take a little trickery to get working:
http://www.haskell.org/haskellwiki/Calling_Haskell_from_C
There is also a project called HaskellDirect which seems similar to your purpose as well:
http://www.haskell.org/hdirect/
AutoCAD uses AutoLisp so my suggestion would be Lisp.
I'd be tempted to check out qtHaskell and to do the whole thing in Haskell. My opinion is based on Don Stewart's remarkable success doing xmonad in Haskell.
Lisp and Haskell are excellent functional languages but if we consider the ease of binding C/C++ code along with the language, I'd recommend lua.
It is extremely straightforward to bind C functions to lua right off the bat, the interpreter is super compact and easy library to build, it's among the fastest scripting languages out there, and, with luabind, you can easily bind C++ classes, template instantiations, etc. I've had to do bindings for numerous scripting languages in the past and I've never found one that's quite as straightforward as lua. It's also supported with swig if you prefer to bind things through swig which will allow your application to support multiple scripting languages.
From a pure language point of view, the meta-feature/metaprogramming aspect of lua (comparable to lisp) makes it very easy to support all kinds of programming paradigms, though I personally find it best suited for functional programming. It's extremely customizable and well-suited for embedded use.
However, since you are already using qt, qtHaskell might be a nice choice to consider as well.

What apps do program in C++ nowadays

With RoR, Java, C#, PHP etc.. what do people use C++ for these days?
You're comparing apples to oranges. Languages such as PHP, Ruby, and Python are scripting languages. They a) are interpreted, and b) don't provide the kind of low-level memory access that C++ does, and thus aren't suitable for things that need to talk directly to hardware. Java and C# both run in a runtime environment on top of a particular platform and for the same reason aren't always the best choice. In all of these cases, things such as garbage collection can get in the way of speed and performance.
Languages are just tools; you choose the best tool for the task at hand. Just because higher-level languages make many tasks easier for a particular application domain doesn't mean that lower level languages don't have their place.
C++ is the preferred language when the user experience is more important than
development cost.
Performance. When Users time is valuable enough to spend some extra development hours.
Stability. Other languages may quick whip up something of descent quality.
But If you want it flawless, C++ is a better choise. As usual in c++ it is both
easier to get it totally wrong and totally right, depending on your skill and time available.
Ease of use. You can deliver a single binary that works everywhere. No need
for inexperienced end user to fiddle with installling runtimes and
interpreters, worring about VM versions and GC tweaking.
Users resources. Just because the user has 2gb of ram doesn't mean that she
wants our program to use all of it.
Usability. If you want specialized non-standard streamlined user interface.
Something that seems to have been overlooked so far are projects where there is already a substantial C or C++ code base. Most programming work is not going into creating brand new programs. If you are so blessed as to be creating something completely de novo, great, but that's not the common situation.
It's possible to mix languages, of course, so you can have the old C++ core program with additional code written in some other language. But, this is not easy, for a number of reasons:
There's the impedance mismatch between the languages themselves. Try to send a C++ std::multiset to Perl. It's kind of like an associative array, but not really. You end up using lowest-common-denominator data structures, avoiding anything that's specific to only one of the two languages. You then lose out on some of the features you were trying to gain by mixing languages.
You have to spend a lot of effort to define some kind of API between the two parts of the program. Most programs are not already architected to have such a layer. Refactoring and packaging the old core functionality to provide this is not easy, and it's ongoing work as the program's scope expands.
You either have to integrate the interpreter for the other language into the old C++ core, or you have to run it as a separate program and arrange for coordination between these two different programs. They must start up and shut down together, they have to maintain their IPC channels, etc.
Having overcome all the above, you will frequently find yourself needing to write code for both halves of the program. You will always have some delay while your brain makes a kind of mental context shift between the two languages. It never drops to 0 delay. This soaks up some of the superior productivity of the higher-level language. This is especially bad when working on a new feature in the high-level code that requires adding something to the old C++ core, so you're constantly bouncing between the two. It can be done, but it's a drag on productivity, the main claimed advantage from switching to some other language.
Two of the most common usage of C++ I would think are graphical interfaces and video games programming.
Almost everything on the desktop (except paint.net)
Everything on the server that RoR, php etc is running on top of (any language that can't write it's own compiler is probably written in C++)
Anything embedded smaller than an iPhone
Anything with a lot of computation - that isn't in Fortran ;-) Yes I know C# performance has improved, anybody got round to rewriting LAPACK, BLAS or NAG in it yet?
edit -
Is there a badge for most comments?
This is why SO doesn't work for discussions. Notice the order of comments change as they are voted. If you want to have childish arguements there is always reddit.
Anything where performance is a high priority. Garbage collection, HTML rendering, animation, games, intensive computation...
And from personal experience Computer-aided Design (CAD) plugins/addins are also C++, especially if you want to target multiple CAD systems (e.e Pro/Engineer, SoludWorks, CATIA, UG, AutoCAD etc).
Backends to projects. Many projects are written in multiple languages, where all the backend operations are written in C++ where APIs to other languages are provided.
The best project I can think of that does this is GNU Radio. Basically, how GNU Radio works is that all the DSP blocks (modulators, filters, etc) are written in C++. However, you make your radio using python, that is you connect the blocks together in python.
While other languages have come along. Many poeple who have used C++ in the past aren't just going to jump bandwagon with Java or C#. Linux all well and good in it's own right, but the majority of the computer Market still belongs to the Evil Empire. Java is NOT the dominant language there, no matter how much the religeous zelots claim it to be. Actually in small business apps, VB is king. I think I saw one figure giving it 58% of internal development for GUI front ends. C# is picking up momentum, but I suspect it primarily from the younger crowd who are less set in there ways. You can argue till your blue in the face virtues of a new language with someone who's been using a language for 15 years, and they just won't care. "Oh that's neat." and they turn back around and continue typing their C++.
Edit:
OS development, C maybe C++.
Tool & Langauge development, C maybe C++.
Industrial control, C, C++, Labview in somecases, FPGA development and NO trendy languages.
Embedded alot of C, some C++ and some assembly required.
(The IPhone is a general purpose palm computer, with phone capability. Not special
purpose computer designed for a singular purpose.)
PS3 C, C++ and some assembly required.
XBox360 Some C#, mostly C++ and some C and again some assembly required.
GPU Programming? It ain't PHP that's for DAMN sure.
Windows Programming C++, C#, and even some C still, VB.
Edit:
#Jeff L:
The Cult following that many these language have, I find irrational and distasteful. I start edging away from anyone who waxes poetic about ANY language, it's just mental. It's not a matter of opinion that professionally sold applications AREN'T written in Java for Window, it's fact. I'm sorry, but it's true. Maybe in the IT world it's useful, but not for shrink wrapped Windows software. I write embedded software, and the "feature" of not having pointers means that in order to do any practical work there or on OSs and device drivers requires hacks that violate the language it's self. There are cases where you have to "fly without a net" and the interpretive languages are designed SPECIFICALLY not to let you do that.
And not to be too argumentative with, but the heritage code base is a hard issue to get around. While we write new code in C and C++, I can't even get management PAY to upgrade old code written in Fortran or Ada to C or C++ forget Java that requires a whole new coding standard and butt loads procedures and documentation have to update, that cost even more. And unless the only software you write is GPL and freeware, who's paying for it is the primary concern. And in many cases "if it's isn't broke don't fix it" doesn't even apply, "if it's broke and no one bitching, we're not paying to fix" is managements choice.
Any project that needs direct hardware access, like drivers, operating systems
Any project where better performance is a competitive advantage, like games, simulations
Any project that needs a small footprint, like embedded systems
Check out the click modular router. Written completely in C++ (with some C where necessary)
A lot of micro ISVs are (enthusiastically) using C++ for almost anything you can think of.
It isn't maintained regularly, but here is a list of apps written using C++ Builder. I was pleasantly surprised to see WinRAR and Partition Magic.
I just interviewed with a company that has C++ programs using VS5.0 as they keep planning on phasing the C++ apps out, so updating is not needed. After 12 years you would expect that they would just upgrade their compiler.
If you want to use DirectX the you have to use C++ now, as MS dropped support for a Managed DirectX API.
As was mentioned, in the embedded world C++ or C is the primary languages.
If you work in a system that cannot crash, then you will may use C or C++ and just don't use new or malloc, but use arrays, so that you won't have any memory leaks, which can be a likely reason a long running process may run out of memory and crash.
If you are going to do a great deal of kernel level programming then C or C++ makes more sense as there will be some functions to call that will be incredibly difficult to call from C#, for example.
We do these projects in c++:
Simulation
Game
GIS tools
if you need performance, you should use c++...

What is a good scripting language to integrate into high-performance applications?

I'm a game's developer and am currently in the processing of writing a cross-platform, multi-threaded engine for our company. Arguably, one of the most powerful tools in a game engine is its scripting system, hence I'm on the hunt for a new scripting language to integrate into our engine (currently using a relatively basic in-house engine).
Key features for the desired scripting system (in order of importance) are:
Performance - MUST be fast to call & update scripts
Cross platform - Needs to be relatively easy to port to multiple platforms (don't mind a bit of work, but should only take a few days to port to each platform)
Offline compilation - Being able to pre-parse the script code offline is almost essential (helps with file sizes and load times)
Ability to integrate well with c++ - Should be able to support OO code within the language, and integrate this functionality with c++
Multi-threaded - not required, but desired. Would be best to be able to run separate instances of it on multiple threads that don't interfere with each other (i.e. no globals within the underlying code that need to be altered while running). Critical Section and Mutex based solutions need not apply.
I've so far had experience integrating/using Lua, Squirrel (OO language, based on Lua) and have written an ActionScript 2 virtual machine.
So, what scripting system do you recommend that fits the above criteria? (And if possible, could you also post or link to any comparisons to other scripting languages that you may have)
Thanks,
Grant
Lua has the advantage of being time-tested by a number of big-name video game developers and a good base of knowledgeable developers thanks to Blizzard-Activision's adoption of it as the primary platform for developing World of Warcraft add-ins.
Lua is a very good match for your needs. I'll take them in the same order.
Lua is one of the fastest scripting languages. It's fast to compile and fast to run.
Lua compiles on any platform with an ANSI C compiler, which afaik includes all gaming platforms.
Lua can be pre-compiled, but as a very dynamic languages most errors are only detectable at runtime. Also precompiled code (as bytecode) is often larger in terms of size than source code.
There are many Lua/C++ binding tools.
It doesn't support multi-threading (you cannot access a single instance of the interpreter from multiple threads), but you can have several instances of the interpreter, one per thread, or even one per game object.
Lua have been used in video-game industry for years. Lightweight and efficient.
That being said, ChaiScript and Falcon are good candidates matching your needs and with higher level language than Lua but with less history and community support.
Lua
Boost Python
SWIG
We've had good luck with Squirrel so far. Lua is so popular it's on its way to becoming a standard.
I recommend you worry more about memory than speed. Most scripting languages are "fast enough" and if they get slow you can always push some of that functionality back down into C++. Many of them burn through lots of memory, though, and on a console memory is an even more scarce resource than CPU time. Unbounded memory consumption will crash you eventually, and if you have to allocate 4MB just for the interpreter, that's like having to throw 30 textures out the window to make room.
Lua, and then LuaJIT for extra blaziness!
just don't expect too much from automatic C++ binding libraries, most are slow and restrictive. better do your own binding for your own objects.
as for concurrency, either LuaLanes, or roll your own. if your C++ program is already multithreaded, just call separate LuaStates from each thread, and use your own C++ shared structures as communications channels if needed.
as you might already know, the most often repeated answer in Lua is 'roll your own', and it's often the best advice! except when it's about bindings to common C/C++ libraries, in that case it's quite probable there's already one.
If you haven't looked at it yet I would suggest you check out Angelscript.
I have successfully used it in a cross platform environment (Windows and Linux with only a recompile) and it is designed to integrate well with C++ (both objects and code).
It is lightweight and supports multi-threading (in the sense that the question was asked), performs well and compiles to byte code which could be done in advance.
Start with Python.
If you can prove that you need more speed, then look at Stackless Python. That's what EVE Online uses for their game.
JavaScript may be a reasonable option, because of the mountains of effort that have gone into optimizing the various implementations for use in web-browsers.
These come to mind:
Lua
Python with boost::python
MzScheme or Guile
Ruby with SWIG

What's the best alternative to C++ for real-time graphics programming? [closed]

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C++ just sucks too much of my time by making me micro-manage my own memory, making me type far too much (hello std::vector<Thingy>::const_iterator it = lotsOfThingys.begin()), and boring me with long compile times. What's the single best alternative for serious real-time graphics programming? Garbage collection is a must (as is the ability to avoid its use when necessary), and speed must be competitive with C++. A reasonable story for accessing C libs is also a must.
(Full disclosure: I have my own answer to this, but I'm interested to see what others have found to be good alternatives to C++ for real-time graphics work.)
Edit: Thanks everyone for the thoughtful replies. Given that there's really no "right" answer to this question I won't be selecting any particular answer. Besides I'd just pick the language I happen to like as a C++ alternative, which wouldn't really be fair.
What about D Programming Language?
Some links requested in the comment:
Win32 Api
Derelict (Multimedia lib)
I wouldn't discard C++. In fact, I would consider adding Boost to your C++ library, which makes the language much more usable. Your example would become:
BOOST_FOREACH( Thingy& t, lostOfThingys ) {
// do something with 't'
}
Boost has tons of tools that help make C++ a better language.
C# is a nice language that fits your requirements, and it is definitely suited for graphics, thanks to the efforts of Microsoft to provide it with great tools and libraries like Visual Studio and XNA.
Real-time + garbage collection don't match very well I'm afraid.
It's a bit hard to make any real-time response guarantees if a garbage collector can kick in at any time and spend an undefined amount of processing...
I disagree with your premise. When used carefully and properly, C++ is a great language, especially for a domain like real-time graphics, where speed is of the essence.
Memory management becomes easy if you design your system well, and use stl containers and smart pointers.
std::vector::const_iterator it = lotsOfThingys.begin()) will become much shorter if you use
using namespace std;
typedef vector::const_iterator ThingyConstIter;
And you can shorten compile times significantly by breaking up your systems into reasonably self-contained modules, by using precompiled headers, or by using the PIMPL idiom.
Perhaps a hybrid approach. Python and C++ make a good combination (see, for example, PyGame).
Some variation of Lisp that compiles to machine code could be almost as fast as C++ for this kind of programming. The Naughty Dog team created a version of Lisp called Game Oriented Assembly Lisp, which they used to create several AAA titles, including the Jak and Daxter series. The two major impediments to a Lisp approach in the game industry would be the entrenched nature of C/C++ development (both tools and human assets are heavily invested in C/C++), as well as the difficulty of finding talented engineers who are stars in both the game programming domain and the Lisp language.
Many programming teams in the industry are shifting to a hybrid approach wherein the real-time code, especially graphics and physics code, is written in C or C++, but game logic is done in a higher-level scripting language, which is accessible to and editable by programmers and non-programmers alike. Lua and Python are both popular for higher-level scripting.
Let's not forget to mention the new 'auto' use:
auto it = lotsOfThingys.begin(); // Let the compiler figure it out.
auto it2 = lotsOfFoos.begin();
if (it==it2) // It's still strongly typed; a Thingy iter is not a Foo iter.
As a developer/researcher/professor of 3D VR applications for some 20 years I would suggest there is no alternative (except possibly C). The only way to reduce latency and enable real-time interaction is an optimized compiled language (eg C or C++) with access to a fast relaible 3D graphics library such as OpenGL. While I agree it is flustrating to have to code everything, this is also essential for performanc and optimization.
Sometimes, looking outside the beaten path you can find a real gem. You might want to consider PureBasic (Don't let the name mislead you). Here's some details:
PureBasic Features
Machine Code (Assembly) executables (FASM)
In-line Assembly support
No run-times needed (no DLLs needed,etc.) 1 executable file
Tiny executables (as small or smaller/as fast or faster than C++ w/out the runtime)
You can write DLLs
Multi-thread support
Full OS API support
Multi-platform support
Windows 95-2003
Linux
Mac-OS X
Amiga
2D & 3D game development
DirectX
OGRE
Generous Licensing
Inexpensive (79 Euros or about $112)
Life-time license (all future updates & versions included)
One price for all platforms
External Library support
3rd party DLLs
User Libraries
On-line Support
Responsive development team led by it's creator
On-line forum
One place for answers (don’t have to go all over the net)
Huge amount of sample code (try code out while in IE with IEtool)
Fast replies to questions
Bonus learning (alternative to learning C++)
API
Structures
Interfaces
Pointers
Visit the online forum to get a better idea of PureBasic (http://www.purebasic.fr/english/index.php) or the main site: www.purebasic.com
I completely agree with the mention of C# for graphics programming. It has the slight disadvantage of being a managed language and allowing the garbage collector free reign over your application is framerate suicide after a while but with some relatively intelligent pool allocations made early in the program's life any real issues can be avoided.
Several people have already mentioned XNA, which is incredibly friendly and well-documented and I would like to echo that recommendation as well. I'm personally using it for my hobby game projects and it has treated me very well.
XNA isn't the only alternative, though. There is also SlimDX which is under constant development as a means of providing a lean wrapper of DirectX in a similar fashion as Managed DirectX (which was, I believe, discontinued by Microsoft in favor of XNA). Both are worthy of research: http://code.google.com/p/slimdx/
There are no true alternatives for big AAA titles, especially on the consoles. For smaller titles C# should do.
C# is a good answer here - it has a fair garbage collection (although you'd have to profile it quite a bit - to change the way you handle things now that the entire memory handling is out of your hands), it is simple to use, have a lot of examples and is well documented.
In the 3D department it gives full support for shaders and effects and so - that would be my choice.
Still, C# is not as efficient as C++ and is slower due to overhead, so if it is speed and the flexibility to use any trick in the book you like (with pointers and assembly if you like to get your hands dirty) - stick to C++ and the price would be writing way more code as you mentioned, but having full control over everything including memory management.
I would say the D programming language is a good option. You can link to C object files and interface with C++ code through C libraries. D has garbage collection, inline assembly, and game developers have created bindings to SDL and OpenGL libraries, and are also actively working on new game development apis. I love D. Too bad my job doesn't demand it's use. :(
Like James (hopkin), for me, the hybrid approach is the best solution. Python and C++ is a good choice, but other style like C#/C++ works. All depends of your graphical context. For game, XNA is a good platform (limited to win32), in this case C#/C++ is the best solution. For scientific visualization, Python/C++ is accepted (like vtk's bindings in python). For mobile game JAVA/C++ can works...
If you are targeting Windows, C++/CLI (Microsoft's .NET 'managed' dialect of C++) is an interesting possibility, particularly if you want to leverage your C++ experience. You can mix native code (e.g. calls to C-style libraries) with .NET managed code quite seamlessly, and take advantage of .NET GC and libraries.
As far as concerns about GC impacting 'real time' performance, I think those tend to be overblown. The multi-generational .NET GC is very good at never taking much time to do a collection, unless you are in some kind of critical low-memory situation. I write .NET code that interacts with electronic derivatives exchanges, where time delays == lots of $$$, and we have never had a GC-related issue. A few milliseconds is a long, long time for the GC, but not for a human interacting with a piece of software, even a 'real time' game. If you really need true "real time" performance (for medical devices, process control, etc.) then you can't use Windows anyway - it's just not a real-time OS.
Lot of game engines can fit your need, I suppose. For example, using SDL or Cairo, if portability is needed. Lot of scripting languages (coming in general with easy syntax and garbage collection) have binding to these canvas.
Flash might be another alternative.
I will just point out Processing, which is an open source programming language and environment for people who want to program images, animation, and interactions.
Actually, it is a thin wrapper around Java, making it look like a scripting language: it has a (primitive) IDE when you can type a few lines of code and hit Run without even having to save the file. Actually it wraps the code around a class and adds a main() call, compiles it and run it in a window.
Lot of people use it for real-time exhibitions (VJ and similar).
It has the power and limitations of Java, but adds out of the box a number of nice wrappers (libraries) to simplify access to Java2D, OpenGL, SVG, etc.
Somehow, it has become a model of simple graphics language: there are several applications trying to mimic Processing in other languages, like Ruby, Scala or Python. One of the most impressive is a JavaScript implementation, using the canvas component implemented in Firefox, Safari, Opera, etc.
I vote c++0x. Partial support is already available in gcc-4.3+ using the -std=c++0x flag.
Would 'C' be too obvious an answer?
I have very successfully used C++ for the engine, with the application written in Lua on top. JavaScript is also very practical, now the latest generation of JIT based JS engines are around (tracemonkey, V8 etc).
I think C++ will be with us for a while yet; even Tim Sweeney hasn't actually switched to Haskell (pdf) yet, AFAIK :-)
Java and LWJGL (OpenGL wrapper) has worked well for me. If you're looking for more of a scene graph type library like Orge have a look at jMonkeyEngine which we used to create a google earth type application (see www.skapeworld.com). If you're sensible with object creation the garbage collection is a non issue.
If your target is a PC, I think you can try C#, or embed Lua in your C++ app and run scripts for 'high-level' stuff. However if your target is a console, you must manage your own memory!
Objective-C looks like a good match for your requirements (the latest version with optional GC), although it is too dynamic and Smalltalk-like for my taste.
XNA is your best bet I think. Being supported by the .NET framework you can build for a Windows or Xbox 360 platform by simply changing a setting in Game Studio. Best yet, all the tools are free!
If you decide to go with XNA you can easily get started using their quickstart guide
XNA Quickstart guide
It has been a rewarding and fun experiance for me so far, and a nice break from the memory management of C++.
Garbage collection is a must (as is
the ability to avoid its use when
necessary)
You can't disable a garbage collector temporarily. You would need a deterministic garbage collector then. But such a beast does come with a performance hit also. I think BEA JRockit is such a beast and then you should stick to Java.
Just to comment on your example; typedef is your friend...
typedef std::vector<Thingy> Thingys;
Thingys::const_iterator it = lotsOfThingys.begin()
Don't overlook independent languages in your quest. Emergence BASIC from Ionic Wind Software has a built in DirectX 9 engine, supports OOP and can easily interface with C libraries.
http://www.ionicwind.com
James.
The best enviroment for your project is the one you get your task done in the fastest way possible. This - especially for 3D-graphics - includes libraries.
Depending on the task, you may get away with some minor directx hacking. Then you could use .NET and slimdx. Managed languages tend to be faster to programm and easier to debug.
Perhaps you need a really good 3D-engine? Try Ogre3D or Irrlicht. You need commercial grade quality (one might argue that Ogre3D offers that) - go for Cryengine or Unreal. With Ogre3D and Irrlicht you might uses .NET as well, though the ports are not always up to date and plugins are not as easyly included as in the C++ versions. For Cryengine/Unrealengine you won't have a real choice I guess.
You need it more portable? OpenGL for the rescue - though you might need some wrapper (e.g. SDL).
You need a GUI as well? wxWidgets, QT might be a possiblity.
You already have a toolchain? Your libraries need to be able to handle the file formats.
You want to write a library? C / C++ might be a solution, since most of the world can use C / C++ libraries. Perhaps with the use of COM?
There are still a lot of projects/libraries I did not mention (XNA, Boost, ...) and if you want to create some program that does not only display 3D-graphics, you might have other needs as well (Input, Sound, Network, AI, Database, GUI, ...)
To sum it up: A programming language is a tool to reach a goal. It has to be seen in the context of the task at hand. The task has its own needs and these needs may chose the language for you (e.g. you need a certain library to get a feature that takes long to programm and you can only access the library with language X).
If you need the one-does-nearly-all: try C++/CLI (perhaps in combination with C# for easier syntax).
Good question.
As for the 'making me type far too much', C++0x seems to address most of it
as mentioned:
auto it = lotsOfThingys.begin()) // ... deduce type, just like in *ML
VS2010beta implements this already.
As for the memory management - for efficiency - you will have to keep good track of memory allocations, with or without garbage collection (ie, make memory-pools, re-use allocated object sometimes) anyhow, so that eventually whether your environment is garbage collected or not, matters less. You'll have to explicitly call the gc() as well, to keep the memory from fragmenting.
Having consistent ways to manage memory is important anywhere.
RAII - is a killer feature of C++
Another thing - is that memory is just one resource, you still have to keep track of other resources with a GC, so RIAA.
Anyhow, C# - is a nice alternative in many respects, I find it a very nice language, especially the ability to write functional-style code in it (the cute lambda -> syntax, map/select 'LINQ' syntax etc), thus the possibility to write parallel code; while it's still a 'standard curly-brackets', when you (or your colleagues) need it.
Have a look to Delphi/Pascal Object and some exemples :
http://www.delphigamer.com or http://glscene.cjb.net/
You can look at Ada. There is no garbage collector but this language is oftenly used for real-time system needing high reliability. That means less debuging times for your 3D applications.
And, you can also look at Haskell, if you don't know the functional paradigm this language will look weird to you, but it's worth a bit of your time. Tim Sweeney (EPIC Inc) is considering this language as a C++ alternative.