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Disclaimer: Yes I know this will take 3 years, at least.
I am looking forward to writing a new interpreted programming language. I have a quite solid idea of what I want in terms of dynamicness, syntax, object model, etc, etc.
Now that I have the idea, I have a few questions before I start:
Should I begin writing the full specification and then implement, or write them both all along?
I'm still doubting between C and C++. C++ would allow for more clean design and faster development while C would (maybe) ensure portability to more platforms (microprocessors?). Performance is a must.
Should I try to interest people for the project before the first working prototype so they can cooperate (the end product will be a liberal license anyway), or keep working alone until I have something that runs?
How modular should it be? I am sure that I won't immediately start working on a bytecode interpreter but something easier to implement but slower thing first, so modularity is a must in order to be able to extend later, but I guess overdoing it will hamper performance and clearity.
The answers to your questions depend largely on why you're doing this- the primary reason. Are you trying to create the next Ruby, or is this a learning exercise?
Specification: If this is a personal project, this is not as important. PHP gets a bad rap for having been developed "on the fly," yet many people use it every day. A more complete spec will probably help get people involved if/when you want help.
If you want cross-platform and performance, C is the way to go.
If you want people to join in, prove something first. Write a killer-cool application with your language and blog/talk about why your language is different/special/better.
Modularity of what, the language itself or the compiler? If you want to extend the language, a good spec will help (see #1.) The compiler should be designed with all the best practices in mind, which should help make it extensible.
I hear the Dragon Book is good for learning to develop compilers.
Your specification will be broken unless you write it hand-in-hand with the implementation.
If you think C++ would give you cleaner design and faster development, you should probably use it.
You will have difficulty getting anyone interested in a project unless there is something that runs and demonstrates what is unique about your language.
If you think your language will ever require a byte-code interpreter (and you do say "Performance is a must") you should investigate the capabilities of existing byte-code interpreters before you finalize your language design.
I think you have set yourself too many goals. You say "performance is a must" but in a comment reply you say your goal is "to learn a lot about language design" and that it is "pretty unlikely" that you'll use it in a real project. New programming languages are created to solve problems; more precisely, they're created to help people express solutions to problems in better ways. Designing a language without using it seriously, intensely, continually is like writing software without any test cases: you're likely to wind up with something unusable.
If you want to try your hand at language design, then find a problem---one that you care about---that existing languages won't let you solve the way you want. Then do whatever you can to get a working implementation and start writing and running programs using it. You don't need a hand-crafted JIT compiler with a runtime written in highly bummed assembly code. If you target the JVM or .NET, you get a very high-performance GC, scalable threading system, libraries, and lots of other good stuff for free, even if it interferes with that awesome idea you had for ______.
On the other hand, if you just want to make something run fast, don't try to design a language at the same time. Just find one that you like, learn about implementation strategies, and see if you can do better.
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I'd just like to ask if there are other alternatives for REALStudio or Runtime Revolution?
I'm not looking for something like a .NET framework or a plugin. I want it to be fully self-contained like the aforementioned IDEs.
It should also be cross-platform.
NOTE:
Please don't mention Java. I already know of it.
Just to be clear, I'm looking for a programming environment that would let me create a desktop application for Windows, Mac OS X and Linux...
I still feel like I'm shooting in the dark by answering this question. It's unclear if you're looking for a programming language and GUI toolkit, or if you just want an IDE that is cross-platform. It's also unclear why you are abandoning REAL Studio, since it seems to meet your requirements.
Anyway, there are really a lot of options here, especially if you don't need one that uses the REALbasic language. I can only talk about the ones I am familiar with and have experience in using. Others can surely tell you more about dynamic languages like Perl, Python, Ruby, etc. etc.
First off, I'm not sure why you think that the .NET Framework is not "fully self-contained". Yes, it requires a runtime, much like Java does. But those two managed languages have gotten quite a bad rap for requiring a runtime. It seems people have forgotten that programs compiled in C and C++ can often require a runtime as well (at least they do on Windows).
I would take a second look at .NET. It is an extremely easy-to-use, rapid development environment, much in the style of REALbasic. VB.NET retains a lot of the syntax, while bringing you (in my opinion) even more powerful features. Since almost all desktop applications should be distributed with an installer (setup program), the requirement of a runtime is really a non-issue. Your installer should install the necessary dependencies at the same time as your application—the user will never be the wiser.
Of course, producing a desktop application with a user interface that is truly native across all three of your target platforms is going to be difficult at best. Windows, Mac OS X, and Linux all have vastly different platform conventions, and even though you can find environments that will let you generate an executable that runs on all those platforms, none of them are going to produce interfaces that actually look like a native application. I'm extremely picky about this, and you'll find that Mac users are, too. Windows and Linux users are much more accepting, but following standard platform conventions is the key to making your app easy to use and easy to understand. Conforming to the behavior the user expects and taking advantage of native widgets has a lot of advantage that developers (often prone to reinvent the wheel) seem to be forgetting recently.
The absolute best thing to do (in my opinion) is to write your code in a portable language like C++, and create the user interface using tools provided for each platform (For Windows, you might use the Windows API, or WinForms or WPF provided by the .NET Framework. For Mac OS X, you'll use Cocoa and Apple's Xcode/Interface Builder. For Linux, you'll do whatever it is Linux people do.) Then, you just have to recompile your application on each platform, and you get the best of both worlds.
A good compromise would be to use a GUI toolkit for C++ like Qt or wxWidgets that promises to generate cross-platform applications. Yes, the apps themselves are truly cross-platform, but they don't always have truly native interfaces. I understand that Qt has gotten better recently, but it's still not up to my standards. You and your users might be less picky. Note the "your users" part there. The Mac Office team discovered that Mac OS X users just wouldn't accept the ribbon as it was implemented in Windows. Mac Office 11 finally brings the ribbon to the Mac, but it looks completely different, having been entirely reimplemented to look like a native Mac OS X widget. By contrast, Apple's iTunes sticks out like a sore thumb on Windows. What's long been the standard for an innovative, easy-to-use interface on the Mac is regarded by many PC users as an abomination. But then again, native GUI is sort of my soapbox, so if you care, I recommend perusing my answers to other, similar questions:
Advice for supporting both Mac and Windows Desktops
What is the best library to use when writing GUI applications in C++?
If you goal is to have a self contained IDE with an easy to use GUI builder, that can produce standalone cross platform executables, then to the best of my knowledge, the options are pretty limited.
If you like BASIC (similar to RealBasic or RunRev), then you may want to look at www.PureBasic.com . Documentation and new material is sparse, IMHO. It has it’s own GUI builder, but for a bit more cash, you may want to pair it with PureVision.
For cross platform development using wxWidgets programming in C++, wxPython, wxLua or wxRuby, you may want to consider DialogBlocks.
The answers given here are terrible of course, but the question you are asking is a difficult one and there may not be an answer. I'm asking myself the same question as REALStudio doesn't work as well as I would like. Java is poor, difficult and ugly. .NET is the favourite but not cross platform.
Consider that appearance is a major problem. If the GUI doesn't look native, there's no reason why you can't design something superior (look at MojoWorld for example). I would tentatively suggest REBOL. Although it appears to be an interpreter a compiler could be purchased. As the software is free, if your program works reasonably well you might then buy the compiler. Not sure if it has an interface builder as the buttons are generated by code. The free version is moderately poor but has been improving in recent years.
Not being able to update the interface from a thread (Cocoa for example, I guess NextStep is really old now) seems to defeat the whole object of the exercise. Having Timers that don't run (REALStudio) also seems hopeless given that those are supposed to update the interface instead. Then you have Object-Orientation, an excuse for poor programmers unable to understand code. Not being able to 'GOTO' a button unless you put the code into a Timer pretending that it's a module (yey for for REALStudio). I can understand your problems. Try to realise that programming is HARD and that it only looks easy when you see the end results produced by experts like Apple.
So Java is proof that cross platform doesn't work. Give REBOL a try.
I am working on a new language, targeted for web development, embeding into applications, distributed applications, high-reliability software (but this is for distant future).
Also, it's target to reduce development expenses in long term - more time to write safer code and less support later. And finally, it enforces many things that real teams have to enforce - like one crossplatform IDE, one codestyle, one web framework.
In short, the key syntax/language features are:
Open source, non-restrictive licensing. Surely crossplatform.
Tastes like C++ but simpler, Pythonic syntax with strict & static type checking. Easier to learn, no multiple inheritance and other things which nobody know anyway :-)
LLVM bytecode/compilation backend gives near-C speed.
Is has both garbage collection & explicit object destruction.
Real OS threads, native support of multicore computers. Multithreading is part of language, not a library.
Types have the same width on any platform. int(32), long(64) e.t.c
Built in post and preconditions, asserts, tiny unit tests. You write a method - you can write all these things in 1 place, so you have related things in one place. If you worry that your class sourcecode will be bloated with this - it's IDEs work to hide what you don't need now.
Java-like exception handling (i.e. you have to handle all exceptions)
I guess I'll leave web & cluster features for now...
What you think? Are there any existing similar languages which I missed?
To summarize: You language has no real selling points. It just does what a dozen other languages already did, with syntax and semantics just slightly off, depending on where the programmer comes from. This may be a good thing, as it makes the language easier to adapt, but you also have to convince people to trouble to switch. All this stuff has to be built and debugged and documented again, tools have to be programmed, people have to learn it and convince their pointy-haired bosses to use it, etc. "So it's language X with a few features from Y and nicer syntax? But it won't make my application's code 15% shorter and cleaner, it won't free me from boilerplate X, etc - and it won't work with my IDE." The last one is important. Tools matter. If there are no good tools for a language, few people will shy away, rightfully so.
And finally, it enforces many things that real teams have to enforce - like one crossplatform IDE, one codestyle, one web framework.
Sounds like a downside! How does the language "enforce one X"? How do you convince programmers this coding style is the one true style? Why shouldn't somebody go and replace the dog slow, hardly maintained, severly limited IDE you "enforce" with something better? How could one web framework possibly fit all applications? Programmers rarely like to be forced into X, and they are sometimes right.
Also, you language will have to talk to others. So you have ready-made standard solutions for multithreading and web development in mind? Maybe you should start with a FFI instead. Python can use extensions written in C or C++, use dynamic libraries through ctypes, and with Cython it's amazingly simple to wrap any given C library with a Python interface. Do you have any idea how many important libraries are written in C? Unless your language can use these, people can hardly get (real-world) stuff done with it. Just think of GUI. Most mayor GUI toolkits are C or C++. And Java has hundreds of libraries (the other JVM languages profit much from Java interop) for many many purposes.
Finally, on performance: LLVM can give you native code generation, which is a huge plus (performance-wise, but also because the result is standalone), but the LLVM optimizers are limited, too. Don't expect it to beat C. Especially not hand-tuned C compiled via icc on Intel CPUs ;)
"Are there any existing similar
languages which I missed?"
D? Compared to your features:
The compiler has a dual license - GPL and Artistic
See example code here.
LDC targets LLVM. Support for D version 2 is under development.
Built-in garbage collection or explicit memory management.
core.thread
Types
Unit tests / Pre and Post Contracts
try/catch/finally exception handling plus scope guarantees
Responding to a few of your points individually (I've omitted what I consider either unimportant or good):
targeted for web development
Most people use php. Not because it's the best language available, that's for sure.
embeding into applications
Lua.
distributed applications, high-reliability software (but this is for distant future).
Have you carefully studied Erlang, both its design and its reference implementation?
it enforces many things that real teams have to enforce - like one crossplatform IDE, one codestyle, one web framework.
If your language becomes successful, people will make other IDEs, other code styles, other web frameworks.
Multithreading is part of language, not a library.
Really good languages for multithreading forbid side effects inside threads. Yes, in practice that pretty much means Erlang only.
Types have the same width on any platform. int(32), long(64) e.t.c
Sigh... There's only one reasonable width for integers outside of machine-level languages like C: infinite.
Designing your own language will undoubtedly teach you someting. But designing a good language is like designing a good cryptosystem: lots of amateurs try, but it takes an expert to do it well.
I suggest you read some of Norman Ramsey's answers here on programming language design, starting with this thread.
Given your interest in distributed applications, knowing Erlang is a must. As for sequential programming, the minimum is one imperative language and one functional language (ideally both Lisp/Scheme and Haskell, but F# is a good start). I also recommend knowing at least one high-level language that doesn't have objects, just so you understand that not having objects can often make the programmer's life easier (because objects are complex).
As for what could drive other people to learn your language... Good tools/libraries/frameworks can't hurt (FORTRAN, php), and a big company setting the example can't hurt (Java, C#). Good design doesn't seem to be much of a factor (a ha-ha-only-serious joke has it that what makes a language successful is using {braces} to delimit blocks: C, C++, Java, C#, php)...
What you've given us is a list of features, with no coherent philosophy, or explanation as to how they will work together. None of the features are unique. At best, you're offering incremental improvements over what's already there. I'd expect there's already languages kicking around with what you've said, it's just that they're still fairly obscure, because they didn't make it.
Languages have inertia. People have to learn new languages, and sometimes new tools. They need incentive to do so, and 20% improvement in a few features doesn't cut it.
What you need, at a minimum, is a killer app and a form of elevator pitch. (The "elevator pitch" is what you tell the higher-ups about your project when you're in the elevator with them, in current US business parlance.) You need to have your language be obviously worth learning for some purpose, and you need to be able to tell people why it's worth learning before they think "just another language by somebody who wanted to write a language" and go away.
You need to form a language community. That community needs to have some localization at first: people who work in X big company, people who want to do Y, whatever. Decide on what that community is likely to be, and come up with one big reason to switch and some reasons to believe that your language can deliver what it promises.
No.
Every buzzword you have included in your feature list is an enormous amount of work to be spec'd, implemented, documented, and tested.
How many people will be actively developing the language? I guess the web is full of failed programming language projects. (Same is true for non-mainstream OSes)
Have a look at what .Net/Visual Studio or Java/Eclipse have accomplished. That's 1000s of years of specification, development, tests, documentation, feedback, bug fixes, service packs.
During my last job I heard about somebody who wrote his own programming framework, because it was "better". The resulting program code (both in the framework and in the applications) is certainly unmaintainable once the original programmer quits, or is "hit by a bus", as the saying goes.
As the list sounds like Java++ or Mono++, you'd probably be more successful in engaging in an existing project, even if it won't have your name tag on it.
Perhaps you missed one key term. Performance.
In any case, unless this new language has some really out-of-this-world features(ex: 100% increase in performance over other web development languages), I think it will be yet another fish in the pond.
Currently I'm responsible for maintaining a framework developed/owned by my company. It's a nightmare. Unless there is a mainstream community, working on this full time, it's really an elephant. I do not appreciate my company's decision to develop its own framework(because it's supposed to be "faster") day 'n night.
The language tastes good in my opinion, I don't want use java for a simple website but I would like to have types and things like that. ASP .NET is a problem because of licensing and I can't afford those licenses for a single website... Also features looks good
Remember a lot of operator overloading: I think is the biggest thing that PHP is actually missing. It allows classes to behave much more like basic types :)
When you have something to test I'll love to help you with it! Thanks
Well, if you have to reinvent the wheel, you can go for it :)
I am not going to give you any examples of languages or language features, but I will give you one advice instead:
Supporting framework is what is the most important thing. People will tend to love it or hate it, depending on how easy is to write good code that get job done. Therefore, please do usability test before releasing it. I mean ask several people how they will do certain task and create API accordingly. Then test beta API on other coders and listen carefully to their comments.
Regards and good luck :)
There's always space for another programming language. Apart from getting the design right, I think the biggest problem is coming across as just another wannabe language. So you may want to look at your marketing, you need a big sponsor who can integrate your language into their products, or you need to generate a buzz around it, easiest way is astroturfing. Good luck.
http://en.wikipedia.org/wiki/List_of_programming_languages
NB the names G and G++ aren't taken. Oh and watch out for the patent trolls.
Edit
Oops G / G++ are taken... still there are plenty more letters left.
This sounds more like a "systems" language rather than a "web development language". The major languages in this category (other than C++/C) are D and Go.
My advice to you would be to not start from scratch but examine the possibility of creating tools or libraries for those languages, and seeing just how far you can push them.
I'm a Python programmer who knows a bit of Ruby and PHP as well. I don't really know enough about Java to do anything meaningful, and I certainly don't know C, C++, or other low-level languages. I've heard all the "Who cares about speed because hardware is cheap, but coders are expensive" arguments, and I'm not trying to raise a debate here. I want to understand 2 things about the community of lower level programming languages (whether it's C or even assembly):
What is the main reason you choose to still use it (job requirements, speed, desktop vs web, etc)?
Is it still worth me taking the time to learn C++ (monetarily speaking) or others this late in the game, or will I benefit?
Also, consider the benefits / disadvantages of dynamic vs static typing, when choosing your reasons. I primarily program for the web, but don't take that fully into consideration because it's partly due to the fact that the web is all I know.
Unashamed Fortran programmer here. Speed speed speed. Oh, and all the scientists I work with are reasonably fluent in Fortran. But then I work in computational electromagnetics on large clusters and supercomputers and wouldn't recognise a web application if it leapt up and bit me on the nose.
I wouldn't regard Fortran as low-level or less-expressive, I think it's a DSL for linear-algebra and more general number-crunching. So why did I take the bait and respond to this question ?
Dynamic vs static typing ? Static please, everything tied down at compile time so the compiler can work its socks off optimising.
For a web programmer, C/C++ will offer you virtually no advantage. It is less expressive than Perl, Ruby, Python, etc. and requires more code and attention to detail of memory management. Unfortunately, choosing a language for its "features" is often second to choosing for its platform. C++ isn't as clean and elegant as C#, most of that comes from its C compatibility. Sadly, even though there are better languages for certain things, most aren't compiled and most aren't widely supported.
If you plan to develop a commercial product that the customer will download or receive on CD, then C/C++ offers you protection of your Intellectual Property (hard to reverse engineer), and a small runtime footprint, as well as ability to target older platforms like Windows XP.
It is not too late in the game to learn C/C++. C/C++ will be around as long as all the higher level languages are around, because those languages are implemented in C/C++. It is not as if we will all move to Python one day and C/C++ will be retired. High level, non-compiled languages are not self-hoisting, so they cannot exist without C++.
It is the tool to use if you are going to implement higher level things like languages, APIs, toolkits, drivers, IDEs, etc. But C++ is not the tool to use if you want the fastest way to develop an internal GUI app or a Web app.
Just learn the tool for the job. If the job changes, or you wish to change the job, then you may want to push yourself to learn C++ to see the other side of the Computer Science world, the side between the CPU and what you currently write your web apps in.
I'd think the big three reasons here are going to be Performance, Legacy System Support, and Embedded Development.
So mega subjective it renders any answer next to useless.
For the numerical calculations I do writing straight C++ is just faster than using e.g. straight Python. Sure, I can interface my C++ libraries to higher-level languages (and I do), but since most of my work is done on the low-level numerical side, I wouldn't gain too much.
Also consider that a lot of libraries especially in scientific computation are in FORTRAN, C or C++ and linking against them from C++ is much faster (especially if you just want to get done with it) that creating wrappers and interfaces all yourself.
If you would gain anything from learning a low-level language depends a lot on your problem domain.
There are several good reasons for lower-level languages.
First, there's a lot of applications where performance does matter. The main application I work on is slow enough as it is (it does a whole lot of things), and would be unusable in Python.
Second, there are applications that require standalone executables that aren't all that big.
Third, there's a tremendous amount of legacy code in C and C++, and it isn't going away any time soon.
Fourth, operating systems are normally written in C or C++ or similar languages, and expose APIs in them. If you need to get chummy with the OS, for whatever reason, you're better off using the OS language.
Dynamic typing is very clearly better for getting an application up and running fast, and my Lisp background pushed me to believe that static typing is normally just premature optimization. However, lots of people believe that static typing is much better for enforcing correctness in large projects, and C and C++ are well suited for large projects.
For your second question, I have no idea what you want to do in the future, so I don't know if it would be worthwhile for you to learn C++. For professional development, I'd strongly suggest learning a variety of languages, including C or a similar language. There are other questions on SO about what languages to learn.
Why aren't Python, Ruby and PHP written in itself?
Mission critical applications need best possible performance and algorithms and doesn't need things like metaprogramming.
C++ has some great ideas and libraries, which I then found in those modern languages, sometimes better sometimes worse (compare power of templates in C++ and generics in Java).
Low level languages will make you learn something more about lower level abstractions of the computer, operating systems or networks.
Static restricts you in programming and often makes you write out the types, however it also let's you better express your intent in a way, which is automatically provable by compiler and you can get support for tools. Dynamic gives you free hands, you can do more and maybe easier, however you have to test better.
I may be misunderstanding you here but it sounds like you're under the impression that C++ is the appropriate language for every kind of project. It isn't. You wouldn't use a Liebherr truck for a cross country road trip. Every popular language in existence got that way because it works well for some situations. There was a time when C++ was used to write web applications which quickly gave way to Perl scripts because the trade-off between production and performance. So in response to your first question, mainly people still use it because in certain situations it's the best tool for the job.
As far as whether or not you should learn it, I say if you have the time and the desire go for it. Even if C++ is never the correct tool for any of the projects you take on a decent understanding of concepts that are necessary in C++ will make you a better developer in every language.
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In every technical publication, and on this site too, people are always comparing OO languages to Smalltalk. My experience is in Java: is Smalltalk so important that I should study it?
Smalltalk was one of the earliest object-oriented (OO) languages (with others like Simula and Eiffel) and can be said to be extremely "pure" in an OO sense:
Everything is an object and objects are only communicated with via the sending of messages
No primitives (no ints, booleans etc)
No control structures (no for, while, if etc). Sounds impossible but it's true!
No statics
It also pioneered some other, now common, stuff:
the virtual machine (and JIT compilation)
Debugging by inspection
"Hotswapping" running code
the modern IDE
Closures
Duck typing
Model-View Controller (MVC) architecture for UIs
Test-driven development (TDD) and agile methodology
And there are other things connected with Smalltalk which didn't really make it into the mainstream:
"Image"-based system rather than file-based.
Object-oriented databases
And it's fair to say that the Java collections API and the apache-commons collections API are heavily influenced by Smalltalk.
I wouldn't say that you should learn Smalltalk per se, but a familiarity with the fundamentals of these features (now present in many other languages) is surely advantageous to you.
Note that there are currently only 123 questions on here about the language, which was originally intended as an educational language (i.e. aimed at children) by its creator, Alan Kay. It is not particularly heavily used anymore. That's not to say it isn't used. JPMorgan, for example, has a large exotic derivatives risk-management system written in it.
Smalltalk has many brilliant innovations - things we're all taking for granted today, including:
being the first ever IDE
providing programmatic support for a GUI with a mouse If you learn Smalltalk GUI programming, you really will have understood MVC properly.
being built out of a small number of powerful ideas that work together extremely well
The Smalltalk way isn't to crash out on unexpected behaviour - it's to adapt. If you send a message to an object that doesn't understand it, the debugger comes up and invites you to write that method... so it provides excellent support for incremental development.
The IDE, the app that you're writing and your data are all part of the same system - so you can write your own tools and debug instrumentation far more easily.
The TDD toolset in Smalltalk is still better than any other language (see below).
Squeak Smalltalk has quite a bit of cutting-edge design research:
the morphic UI - you can get familiar with the concept of "liveness"
the seaside web framework - learn what a continuation server is and how it's radically different
Squeak has a strong connection with the OLPC software (one laptop per child) project - and could yet have a big influence on the world.
Find out what a "trait" is...
Play with the radical 3D immersive environment called Open Croquet.
Because Smalltalk is a smaller, simpler and more consistent language, with it's own built-in environment it's a much less confusing place to start teaching OOP. People who go this route end up being better Java, Ruby and C# programmers because they can learn basic OOP without all the messy inconsistencies of mainstream languages.
Some commercial Smalltalks have amazing, multi-node distributed OO database environments. I'm thinking about Gemstone.
Want to know the difference between Model-View-Controller and Model-View-Presenter - look at Dolphin Smalltalk...
The single most important reason to learn Smalltalk today is that extreme programming and scrum both got invented in the Smalltalk community... and the highly interactive style of programming you experience in Smalltalk is simpler, more powerful and direct than anything you can do with Java or C# or Ruby... and you can't really understand how well agile methods can work until you've tried to do extreme programming in Smalltalk. Few other languages (no mainstream ones anyway) have a comparable feature set.
... to really understand what TDD can be you need to use SUnit. JUnit just shows you where your tests failed. SUnit actually allows you click into the debugger at the point where the test failed and see the actual objects and how they're connected so you can see, live in the debugger how the code failed and fix it right there.
Yes, Smalltalk is so important you should study it. Why? You can understand object-oriented programming in pure, simple form. What people forget is that the Smalltalk-80 "Blue Book" has only about 90 pages devoted to the language—the language is just that simple. The other 300 pages talk about the predefined class hierarchy, which is a masterpiece of design for a class-based, object-oriented language that uses single inheritance. You will get a much deeper understanding of objects (e.g., classes are objects, and they have metaclasses, and so on off to infinity... except the knot is carefully tied to keep the system finite) than you would ever get from studying a hybrid language like Java or C++. Smalltalk matters not just because of its history but because of its simplicity:
Simple enough so you can understand the entire language and the libraries
Shows one idea (objects are all you need) pushed to its logical extreme
Everybody has something to learn from Smalltalk!
Smalltalk is one of the first two original OOP languages, the other being Simula-67. Consequently, there are two large families - the statically typed model centered around method invocation, pioneered by Simula (C++, Java, C# all belong here), and the dynamically typed model centered around message passing, pioneered by Smalltalk (Python, Ruby belong here).
Today, Smalltalk isn't particularly important on its own - there are some people still using it to write stuff, but it's definitely not mainstream. Learning it will give you some insight in how and why OOP evolved, however.
I spent about 5 minutes in a presentation at a conference last month on Smalltalk's history and influence. See Image-based development with Smalltalk. One of the more foreign concepts to today's programmers is the "image-based" development. There are some good analogies, including a DBMS and a spreadsheet.
Yes. Download the seaside one-click image, start using it with the tutorial from James Foster and you will learn at least:
how web applications should be build
how debugging is supposed to work
I agree with the others. I'm not sure if it's important per se, but it is COOL (imho).
I love that there are no loops or conditionals in the language. If-then-else is a message sent to a boolean object. Objects of type True do one thing, objects of type False do another. (Yes, True and False are subtypes of Boolean, with a single value each, true and false respectively).
It starts out being kind of counter-intuitive, but it does give you a very interesting, and deep, view of how OO programming should work...
Not only was it one of the first, Smalltalk remains to this day a paragon of OO language design. The more popular languages that came later — C++, Java, even Objective-C — all have more primitive object-orientation and are more restrictive than good old Smalltalk. Smalltalk had pervasive first-class objects, great support for runtime introspection, very natural use of duck typing and closures that worked better than I've seen in any non-functional language. I mean, we're talking about a language that had no native control structures (if, while, etc.) but was able to create them out of its object system in a way that worked seamlessly. How cool is that?
I wouldn't recommend Smalltalk for any intensive desktop app development these days (there just isn't a viable implementation IMO), but if you want to see how OO was meant to be and maybe pick up some ideas you can use in your apps, Smalltalk is a great place to look.
If you only know one object-oriented language you should consider learning a second and a third and a fourth in order to gain a broader perspective on programming with objects. Learning Smalltalk will stretch your brain because a lot of the familiar concepts we're used to in other languages (e.g. if-then-else, for(;;), while(), etc) are not there in Smalltalk. There are equivalents, obviously, but Smalltalk does things differently, and learning about different ways to do things is always a good idea.
Good luck.
I've just started to revive my interest in Smalltalk, and in my opinion, there are a few compelling things that are special about Smalltalk:
Highly productive development
environment
Built-in support for Agile/Extreme
programming methodologies
"Pure" object model
Easy to use graphics framework
None of these make it especially useful for people who are not in the software development business. My first exposure to it was when I saw a user interface for an embedded device prototyped on a PC using Smalltalk. This allowed the user interface to be modified and tested very quickly, and when completed, provided the embedded developers an "executable specification" that was far more precise than any document. I'm surprised I haven't seen this technique used far more often than I've observed in my travels during the last 20 years.
Using Smalltalk as a prototyping tool is where my interest lies: I think that given a new problem, different approaches to solving it can be tried and validated very quickly and easily in a Smalltalk environment, and once the desired solution is found it should be relatively mechanical to convert it to Java/C++/C# etc. etc. In fact, for repetitive sorts of things, it might well be possible to use Smalltalk to generate code for parts of the solution in some other target language.
The other thing about SmallTalk is that its alumni include Kent Beck and Ward Cunningham. Their work with SmallTalk spawned automated xUnit testing, software design patterns, CRC Cards and other practices which ed into XP/Agile, etc. So it could be argued that SmallTalk has been a major contributor to the modern programming landscape.
Just two comments:
Smalltalk is not object "oriented", is real objects, only objects and messages in the environment.
Smalltalk is not a language, is an environment that has a language (of the same name), but most of the "magic" here is thanks to the environment (the image).