Before Some days my friend ask me some simple questions, but I have no answer.
Please tell me about these questions.
How many computer programming languages are used all in the world ?
I want to create a language like 'java or c#'. What is the procedure for creating a language and how it will create?
Which language is used for manipulate Window operating system?
What is the procedure of create Operating System like Windows/Linux/Mac and in which language it should create?
What is the procedure of create open source framework project in javascript and php?
How many computer programming languages are used all in the world ?
Wikipedia lists a lot of them!
I want to create a language like 'java or c#'. What is the procedure for creating a language and how it will create?
If you need an answer to this question probably you won't be able to create one, I guess (definitely I wouldn't be able to).
Anyway, if you want to go that way and create a very very simple language you should start by building a parser that takes the commands you wrote and interprets them to do something, checks for syntax errors etc. That already will take a big effort.
Which language is used for manipulate Window operating system?
You can use several: C++, C#, Visual Basic, etc etc etc
Microsoft provides several APIs (Application Programming Interfaces) to "manipulate" Windows
What is the procedure of create Operating System like Windows/Linux/Mac and in which language it should create?
As for #2. If you're starting programming you probably better focus on a simple project. Creating an OS is a huge effort and it requires profound knowledge of the computer architecture. You would probably create it using C++ and/or Assembly I guess. (as above, I wouldn't be able to create a programming language, an OS is completely out of question)
What is the procedure of create open source framework project in javascript and php?
This question does not make too much sense to me. You create your project and then release it to the public under an opensource licence, e.g. GPL.
Related
I am seeking a way to allow my non-tech users to specify a workflow and execute it (if anyone is interested, I want them to specify and execute test cases). Visual programming seems a good way to go.
Can I modify the Scratch IDE to remove some categories (such as sound, motion, etc), and add some of my own? Ditto for individual keywords (obviously, I then need to handle new keywords).
I have Googled, but the answer is not immediately apparent.
[Update] I have just found Google's Blockly
Blockly was influenced by App Inventor, which in turn was influenced
by Scratch, which in turn was influenced by StarLogo.
It looks very promising. Especially when it says
Exportable code. Users can extract their programs as JavaScript, Python, PHP, Dart or other language so that when they outgrow Blockly
they can keep learning.
Open source. Everything about Blockly is open: you can fork it, hack it, and use it in your own websites.
Extensible. Make Blockly fit with your application by adding custom blocks for your API and remove unneeded blocks and
functionality.
One possible snag is that it is browser based, but if my management don't like that, then I can create a dummy Windows based app consisting of little but a TWebBrowser component.
I will investigate and report back - unless someone else posts an acceptable answer first.
The short answer to your initial question is: no. You can't customize Scratch, or not to the extent that you seem to ask/want.
That said, look at:
custom blocks.
scratch extensions.
variants like snap
using scratch's source code in squeak to make your own variant.
other systems inspired from scratch, like appinventor and blockly.
Only the first two are compatible with the scratch web site.
A word on the site: depending on your purpose with Scratch, the exchange between users is a powerful part of scratch. Check how cooperation is supported, like the backpack. There's also a good wiki that documents much of the above.
I am trying to create my own programming language but I am already thinking ahead a little.
Of course when I can compile a little program I won't have a Standart Library at that time,
and you'd have to create one yourself. Now take for example I'd like to add some functionality to print a string to the screen, I am pretty sure I'd have to do a few System Calls to the operating system to get this displayed.
So to the point: What would be the best way to interact with the Operating System?
Possibilities I came up with myself:
- Generate Object Files and link those to the (for example) C Standart Library
- Writing the files with embedded assembly language containing System Calls
I have a feeling there are better possibilities!
I hope you can help me,
Christian
EDIT: It's a compiled language I am creating!
You have basically two options, like you say yourself. You can link your standard library with the standard C library, so that the I/O functions in your standard library can use C functions. Alternatively you can make system calls to the operating system directly.
The second approach seems like it's going to be more work: The system calls will be different on each operating system, so you'll have to put a lot of work into porting your system. The system calls may not be well documented, causing many frustrations.
You could start by linking your standard library to the C standard library and worry about other aspects of your language for the moment. Later you can look into replacing the C functions you use with syscalls.
Stdin and stdout are pretty much the minimum - if you are using a Unix environment you can then gain access to they keyboard, command line and also pipe text in and out to files.
If you are writing a new language - then StdError may also be worth considering too!
Can someone give me a clear, concise definition of the difference between a programming language and a framework? I have scoured the web and been unable to find an adequate definition.
For extra credit, is it possible for a language and a framework to become so inextricably linked that there IS no difference, or is there such a clear line between them that this isn't possible?
A language is syntax, grammar, semantics (and perhaps a core library) that implementers are required to support. A framework is a cohesive set of library code that together simplifies programming in any given language.
An application framework is the organizational structure of any application's code, including choices for conventions in files/folders, classes/functions, etc.
An application framework product is any tool that helps generate the framework for an application.
An application design pattern is any conceptual approach for organizing code at the application level.
An software language is a language-based tool that can be used to build applications, utilities, libraries, frameworks, etc.
A library is any extension in functionality to the native compiled functionality of a language.
A standard library is a library packaged with the language product itself.
An external library is a library outside of the language product itself and is either called remotely or installed locally.
A code-generator is any tool that dynamically generates permanent runtime code based on the developer's input.
Regarding the clear line between language and framework, i suppose you can count DSLs (Domain Specific Languages) as constructs that are both a Language and a Framework ( as it is a Framework in the original Language it is build upon).
Lisp is the only language i can think of now that may blur such distinction:
"The name LISP derives from "LISt Processing". Linked lists are one of Lisp languages' major data structures, and Lisp source code is itself made up of lists. As a result, Lisp programs can manipulate source code as a data structure, giving rise to the macro systems that allow programmers to create new syntax or even new domain-specific languages embedded in Lisp."
http://en.wikipedia.org/wiki/Lisp_(programming_language)
I hope i can explain using an example.
Dot net is a framework which consists of large libraries and supports many
programming languages.. C# is a programming language through which you can give
instruction to a machine mainly computer.. Now if your source code is in C#
you can use Dot net framework libraries and the source code which is written in other
languages..
At my point, a programming language looks like bunch of stuff (syntax,grammar, semantics etc.) which people are already combine them into one more convenient, more useful, easier to use, and more enjoyable - a framework, and I love to have a framework before start making a program.
I know some programming languages like C, PHP, ASP, Python, Java, and some frameworks like Yii, Zend, Pygame, Struts. All I see is there can be many frameworks built from a programming language, but a framework is built from only on programming language.
A programming language is a specified, standardized method of communication between the programmer and computer (in modern languages, technically it's between programmer and compiler, which "interprets" your code into simpler instructions the computer can work with). It is a pure abstraction that specifies its structure, syntax and semantics; implementations of the language are generally considered part of the environment in which the programmer develops, and incorporate the compiler and any virtual machine implementation.
A framework is a standardized set of pre-written code libraries designed to be used and reused by developers, and is again tied more to the environment. An environment is the intersection of the language, framework, virtual machine or runtime (an abstraction layer in which managed or interpreted code is translated from a machine-independent form into native code) and machine (the hardware layer on which native instructions are executed).
Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 7 years ago.
Improve this question
I am planning to develop an operating system for the x86 architecture.
What options of programming languages do I have?
What types of compilers are there available, preferably on a Windows environment?
Are there any good sources that will help me learn more about operating system development?
Is it better to test my operating system on a Virtual Machine or on physical hardware?
Any suggestions?
For my final year project in collage I developed a small x86 OS with a virtual memory manager, a virtual file system and fully preemptive multitasking. I made it open source and the code is heavily commented, check out its source forge page at:
https://github.com/stephenfewer/NoNameOS
From my experience I can recommend the following:
You will need x86 assembly language for various parts, this in unavoidable, but can be kept to a minimum. Fairly quickly you will get running C code, which is a proven choice for OS development. Once you have some sort of memory manager available you can go into C++ if you like (you need some kind of memory manager for things like new and delete).
No matter what language you choose you will still need assembly & C to bring a system from boot where the BIOS leaves you into any useable form.
Ultimately, the primary language you choose will depend on the type of OS you want to develop.
My development environment was the Windows port of the GNU development tools DJGPP along with the NASM assembler. For my IDE I used IBM's Eclipse with the CDT plugin which provides a C/C++ development environment within Eclipse.
For testing I recommend BOCHS, an open source x86 PC emulator. It lets you boot up your OS quickly which is great for testing and can be integrated into eclipse so you can build and run your OS at the push of a button. I would also recommend using both VMWare and a physical PC occasionally as you can pick up on some subtle bugs that way.
P.S. OS development is really fun but is very intensive, mine took the best part of 12 months. My advice is to plan well and your design is key! enjoy :)
Language and compiler depend entirely on what you're attempting to accomplish. I would suggest, though, that you might be approaching the problem from too low a level.
There are materials out there on operating system fundamentals. MIT has OpenCourseware on the subject. Read through Andrew Tannenbaum's Operating Systems series, and look at things like Minix.
Get an idea for what's out there. Start tinkering with things. Borrow ideas, and see where they go. You can reinvent the wheel if you really want, but you'll learn more by building on the works of others.
It doesn't really matter, what language you choose. If the language is Turing-complete, then you can write an OS in it.
However, the expressiveness of the language will make certain kinds of designs very easy or very hard to implement. For example, the "liveliness" and dynamism of the old Smalltalk OSs depends on the fact that they are implemented in Smalltalk. You could do that in C, too, but it would probably be so hard that you wouldn't even think about it. JavaScript or Ruby OTOH would probably be a great fit.
Microsoft Research's Singularity is another example. It simply couldn't be implemented in anything other than Sing#, Spec# and C# (or similar languages), because so much of the architecture is dependent on the static type safety and static verifiability of those languages.
One thing to keep in mind: the design space for OSs implemented in C is pretty much fully explored. There's literally thousands of them. In other languages, however, you might actually discover something that nobody has discovered before! There's only about a dozen or so OSs written in Java, about half a dozen in C#, something on the order of two OSs in Haskell, only one in Python and none in Ruby or JavaScript.
Try writing an OS in Erlang or Io, and see how that influences your thinking about Operating Systems!
There is an OS course offered at the University of Maryland that utilizes GeekOS. This is a small, extensively commented OS designed for educational purposes which can be run using the Bochs or QEMU emulators.
For an example of how it is used in a course, check out a previous offering of the course at the class webpage. There, you will find assignments where you have to add different functionality to GeekOS.
Its a great way to get familiar with a small and simple OS that runs on the x86 architecture.
You might want to look up XINU. it's a tiny OS for x86 that isn't really used for anything other than to be dissected by students.
Use ANSI C, and start off with an emulator.
When you port over to a real machine, there will be some assembler code. Context switching and interrupt handling (for instance) is easier to write in assembler.
Andy Tannenbaum has written a good book on OS. Many other good ones exist.
Good luck! There is nothing quite like haveing written your own OS, however small.
Also check out the OSDev.org which have all information you need to get started.
I've done that once for a 386SX, which was on a PCI board. A good source on how to start a X86 cpu in protected mode is the source code of linux. It's just a few assembly statements. After that you can use gcc to compile your C code. The result is objectcode in ELF format. I wrote my own linker, to make a program out of the objectcode. And yes, it worked! Good luck.
Be sure to check out the answers to my question:
How to get started in operating system development
Without a doubt, I'd use Ada. It's the best general-purpose systems-programming language I have come across, bar none. One example, Ada's much better for specifying bit layout of objects in a record than C. Ada also supports overlaying records on specific memory locations. C requires you to play with pointers to acheive the same effect. That works, but is more error-prone. Ada also has language support for interrupts.
Another: Safety. Ada defaults to bound checking array assignments, but allows you to turn it off when you need it. C "defaults" to no bound checking on arrays,so you have to do it yourself manually whenever you want it. Time has shown that this is not the right default. You will forget one where it is needed. Buffer overflow exploits are the single most common security flaw used by crackers. They have whole websites explainng how to find and use them.
As for learning about doing this, the two books I'm aware of are XINU (Unix backwards, nothing to do with Scientology), and Project Oberon. The first was used in my Operating Systems graduate course, and the second was written by Nikalus Wirth, creator of Pascal.
If you are making a full OS, you will need to use a range of languages. I would expect Assembly, C and C++ at the very least.
I would use a Virtual Machine for most of the testing.
C most probably...all major OS-es have been written in C/C++ or Objective-C(Apple)
If you want write an OS then you need a couple of people. A OS can not write a single people. I think it is better to work on existing OS projects
Reactos --> C, Assembler
SharpOS --> C#
JNode --> Java
This is only a short list of OS projects. How you can see there is a project for every possible language.
Is there a general procedure for programming extensibility capability into your code?
I am wondering what the general procedure is for adding extension-type capability to a system you are writing so that functionality can be extended through some kind of plugin API rather than having to modify the core code of a system.
Do such things tend to be dependent on the language the system was written in, or is there a general method for allowing for this?
I've used event-based APIs for plugins in the past. You can insert hooks for plugins by dispatching events and providing access to the application state.
For example, if you were writing a blogging application, you might want to raise an event just before a new post is saved to the database, and provide the post HTML to the plugin to alter as needed.
This is generally something that you'll have to expose yourself, so yes, it will be dependent on the language your system is written in (though often it's possible to write wrappers for other languages as well).
If, for example, you had a program written in C, for Windows, plugins would be written for your program as DLLs. At runtime, you would manually load these DLLs, and expose some interface to them. For example, the DLLs might expose a gimme_the_interface() function which could accept a structure filled with function pointers. These function pointers would allow the DLL to make calls, register callbacks, etc.
If you were in C++, you would use the DLL system, except you would probably pass an object pointer instead of a struct, and the object would implement an interface which provided functionality (accomplishing the same thing as the struct, but less ugly). For Java, you would load class files on-demand instead of DLLs, but the basic idea would be the same.
In all cases, you'll need to define a standard interface between your code and the plugins, so that you can initialize the plugins, and so the plugins can interact with you.
P.S. If you'd like to see a good example of a C++ plugin system, check out the foobar2000 SDK. I haven't used it in quite a while, but it used to be really well done. I assume it still is.
I'm tempted to point you to the Design Patterns book for this generic question :p
Seriously, I think the answer is no. You can't write extensible code by default, it will be both hard to write/extend and awfully inefficient (Mozilla started with the idea of being very extensible, used XPCOM everywhere, and now they realized it was a mistake and started to remove it where it doesn't make sense).
what makes sense to do is to identify the pieces of your system that can be meaningfully extended and support a proper API for these cases (e.g. language support plug-ins in an editor). You'd use the relevant patterns, but the specific implementation depends on your platform/language choice.
IMO, it also helps to use a dynamic language - makes it possible to tweak the core code at run time (when absolutely necessary). I appreciated that Mozilla's extensibility works that way when writing Firefox extensions.
I think there are two aspects to your question:
The design of the system to be extendable (the design patterns, inversion of control and other architectural aspects) (http://www.martinfowler.com/articles/injection.html). And, at least to me, yes these patterns/techniques are platform/language independent and can be seen as a "general procedure".
Now, their implementation is language and platform dependend (for example in C/C++ you have the dynamic library stuff, etc.)
Several 'frameworks' have been developed to give you a programming environment that provides you pluggability/extensibility but as some other people mention, don't get too crazy making everything pluggable.
In the Java world a good specification to look is OSGi (http://en.wikipedia.org/wiki/OSGi) with several implementations the best one IMHO being Equinox (http://www.eclipse.org/equinox/)
Find out what minimum requrements you want to put on a plugin writer. Then make one or more Interfaces that the writer must implement for your code to know when and where to execute the code.
Make an API the writer can use to access some of the functionality in your code.
You could also make a base class the writer must inherit. This will make wiring up the API easier. Then use some kind of reflection to scan a directory, and load the classes you find that matches your requirements.
Some people also make a scripting language for their system, or implements an interpreter for a subset of an existing language. This is also a possible route to go.
Bottom line is: When you get the code to load, only your imagination should be able to stop you.
Good luck.
If you are using a compiled language such as C or C++, it may be a good idea to look at plugin support via scripting languages. Both Python and Lua are excellent languages that are used to script a large number of applications (Civ4 and blender use Python, Supreme Commander uses Lua, etc).
If you are using C++, check out the boost python library. Otherwise, python ships with headers that can be used in C, and does a fairly good job documenting the C/python API. The documentation seemed less complete for Lua, but I may not have been looking hard enough. Either way, you can offer a fairly solid scripting platform without a terrible amount of work. It still isn't trivial, but it provides you with a very good base to work from.