I have an application that is written in SBCL and is deployed as an executable on Windows. The need has arisen for it to interact with Excel via COM and another application via DDE (I know, I know).
DDE is simple enough for me to have quickly wrapped what I needed in a very small, simple to maintain C library. COM, on the other hand, seems like a large enough project to just implement this portion of the functionality in Python with the Win32 extensions library.
This, to me, is annoying in that a lot of CL code is being augmented with some Python that is of varying degrees of integration with the main project.
I've seen that LispWorks and Allegro CL both allow for COM interaction but cannot find any open source implementations of the same functionality via google or CLiki.
Does such a thing exist?
There are bindings called cl-win32ole, implemented using CFFI.
You are asking for Excel integration, so the Excel example included in cl-win32ole might be of interest to you:
I'm not aware of open source COM wrappers that work on multiple CL implementations, SBCL including.
Your best bet might be checking out Corman Lisp which is Windows specific and includes a COM server. Check out its features page: http://www.cormanlisp.com/features.html
My impression is that Corman Lisp isn't actively supported any more but I could be very wrong on that, but at least you might glean something useful from its source code.
Related
This question follows the previous one below:
Easy way to guarantee binary compatibility for C++ library, C linkage?
I wondered if making interface functions of C++ DLL or shared library with C linkage brings forward compatibility of Compiler and of standard library.
extern "C" someAPI();
The most voted answer was saying that I am wrong. The answer recommended making it open-source. And never mentioned about COM or CORBA. Making it open-source is not always possible.
But recently I am reading books about Windows COM. And I think COM maybe brings the compatibility I wanted. And there is another thing CORBA.
So I wonder if these things, COM and CORBA, really brings forward compatibity of compiler and standard library?
I think network library ACE uses CORBA. And that is only one I know about CORBA.
Isn't CORBA popular nowadays?
What about COM? ActiveX is maybe disappearing but WDF(Windows Driver Foundation) depends on COM.
Thank you very much!
Yes, COM was created, among other reasons, to overcome source code (and .obj, static lib, etc.) reuse issues, whether that source is C/C++ or anything else.
The essence of COM (v-table layout + IUnknown, forget about registration, OLE, Automation, marshaling, and other additional stuff) is very simple (in fact, it's hard to make it more simple). Since it only relies on binary contracts, you can write COM client and/or server code using any language (and any platform, but in reality, only Windows uses it). So you can have a 32-bit COM client written in python talk to a 64-bit COM server written in C++ for example (well, this example in fact requires some cross process marshaling, so it's not pure lightweight COM).
COM is very far from being dead or disappearing (because it's, again, quite simple). "ActiveX" was a marketing / tech mix name, but it's basically COM, and is massively used in Windows, by Windows and 3rd parties.
COM over the physical network (DCOM) is indeed disappearing (in favor of other technologies, like Web, sockets, HTTP, REST, or in general technologies more simple than COM), and what's still used today is basically in-process and out-process COM (out-process is somehow DCOM on the same machine).
I know that CORBA was once upon a time a strong COM competitor (especially because it was available on multiple platforms, including Windows), but it seems to be seriously declining, also in favor of the same more simple technologies (web, etc.).
We'd like to offer a compiled library that implement a protocol layer to be imported into C/C++ source code project for microcontrollers. And eventually expose a sort of compiled function to the source code project. let's say a sort of "dll". Is there any know technique to realize something of similar?
While it is possible to provide functions via a library, generally in the microcontroller/embedded realm it quickly becomes impractical.
Each microcontroller core will have a unique instruction set. Further, micros from the same family may have a variety of extensions which are either supported or not... So you're left with providing a library file for each individual microcontroller (from each vendor) that you'd like to support.
But...
In my experience, calling conventions between compilers are not the same. So a library compiled by one toolchain will not be able to be linked to object files created by another toolchain.
That leads you to then provide a library for each individual micro from each vendor for each toolchain someone might use. Ick. Oh, and don't rely on an OS calls either, as you don't know what you'll be linked with...
A more conventional approach is to use the same approach RTOS vendors tend to use: provide the source, and protect your IP with licensing terms. The reality is that if your end users want to, they can step through the assembly and figure out exactly what is happening, so you're not hiding your implementation that carefully anyway.
Ultimate goal would be using VB.net to interface with webcam and do image processing.
Currently I'm just using Matlab, but it is insanely slow. Since I'm going into the area of image processing,coupled with object recognition, which path should I go down to? This by meaning is it GDI+? DirectX? or some other APIs? What is the API that supports manipulating and analyzing graphical input data? By which I may go delve deeper, and create a standalone software just for my own interest/project.
Before going deep into digital image processing with VB.Net, I strongly suggest that you take your time to learn the basics first, after that moving on to the next step which is dealing with the APIs you mentioned.
However, to answer your question, API (Application Programming Interface) is a set of programming instructions and standards communicate your application with other applications.
Which basically allows two different pieces of software to speak to one another through a common interface.
As for the DLL (Dynamic link library) files, they are a set of executable functions or data that can be used by a Windows application.
Or as I quote from Wikipedia:
Dynamic-link library (also written unhyphenated), or DLL, is Microsoft's implementation of the shared library concept in the Microsoft Windows and OS/2 operating systems. These libraries usually have the file extension DLL, OCX (for libraries containing ActiveX controls), or DRV (for legacy system drivers). The file formats for DLLs are the same as for Windows EXE files — that is, Portable Executable (PE) for 32-bit and 64-bit Windows, and New Executable (NE) for 16-bit Windows. As with EXEs, DLLs can contain code, data, and resources, in any combination.
Basically, you shouldn't go too deep while you are in the beginning and I strongly encourage you to start learning the language itself then, step by step until you master the language.
I would like to say something to you IvanWong....Welcome to the world of programming, Fun and challenges!!!
I've got a game in VB6 and it works great and all, but I have been toying with the idea of creating a scripting engine. Ii'm thinking I'd like VB6 to read in flat text script files for me and then lex/parse/execute them.
I have good programming experience, and I've built a simple C compiler, as well as a LOGO emulator before.
My question is:
Are there any tools that I can use, like Lexx/Yakk/Bison to help me? How should I approach this problem in regards to lexing, parsing, and feeding the commands back to VB6 so I can handle them? Is this idea a BAD IDEA in the sense that there are too many obstacles in the way (For example, building minesweeper in assembly, though not impossible, is very difficult, and a bad idea.)?
Use the Microsoft® Windows® Script Control because it is easy to integrate into existing VB6 applications. The control supports VBScript, JScript, or any other "Active Script" implementation.
I have used the Windows Script Control in four projects and it works extremely well. Very easy to integrate. I wish Microsoft would have given us a replacement in .NET, and made it as easy to use. (I understand the control is not needed in .NET, but having the ability to simply create an object that handles everything is nice.)
Windows Script Control
The Microsoft® Windows® Script Control
is an ActiveX® control that provides
developers with an easy way to make
their applications scriptable. This,
in turn, enables users to extend
application functionality through
scripts, much as they do with macros
today.
INFO: Where to Obtain the Script Control at http://support.microsoft.com/kb/184739. Includes links to other howto support articles.
Chapter 13: Adding Scripting Support to Your Application at http://msdn.microsoft.com/en-us/library/aa227413(VS.60).aspx
Designing a Calculator at http://msdn.microsoft.com/en-us/library/aa227421(VS.60).aspx
How To Use Script Control Modules and Procedures Collections, Inserted from http://support.microsoft.com/kb/184745
How To Use the AddObject Method of the Script Control, Inserted from http://support.microsoft.com/kb/185697
SAMPLE: SCRIPTEX.EXE Uses the ScriptControl with Visual Basic, Inserted from http://support.microsoft.com/kb/189484
Windows Script Control can be downloaded at http://www.microsoft.com/downloads/details.aspx?familyid=d7e31492-2595-49e6-8c02-1426fec693ac&displaylang=en. (Supported Operating Systems: Windows 2000; Windows 98 Second Edition; Windows ME; Windows NT; Windows Server 2003; Windows XP)
MSDN Search of "MSScriptControl.ScriptControlClass" at http://social.msdn.microsoft.com/Search/en-US?query=%22MSScriptControl.ScriptControlClass%22&ac=8
MSDN Search of "Windows Script Control" at http://social.msdn.microsoft.com/Search/en-US?query=%22Windows+Script+Control%22&ac=8
MSDN Search of "MSSCRIPT" at http://social.msdn.microsoft.com/Search/en-US?query=MSSCRIPT&ac=8
Unless you're doing it for your own instruction, you may want to try using Lua: VB6 - Lua Integration
If you're willing to use VBScript rather than VB6 you might be able to just use the MSScriptControl to run the commands rather than creating your own. Here's an article discussing using it from a .Net app, though it's an ActiveX control so should give you quite a bit of flexibility.
The control can be downloaded from here.
I've actually seen some quite reasonable implementations of compilers/interpreters in VB6[1] - It's not the language I would choose (few functional features, insufficent static type system), but with experience, you can outweigh these drawbacks and be quite productive - So why not.
You can use the GOLD parser generator that supports VB6 as a start.
[1]: Somewhere on PSC or in this download repository I think ...
Note that there is the MSScriptControl too.
There also appears to be an additonal alternative for VB6:
SadScript is an variant of VB6 most prominently used for VB6 as an scripting engine in MMORPGS .
See here for more : What is sadscript? Can I use it in vb.net? Why hasn't anyone I have asked heard of it?
We have a business logic that works with the file systems on OS that we want to implement on both Linux and Windows platforms. The language we have selected is Python for Linux and C# for Windows. GUI is not a priority for now. We were looking for ways to abstract the business logic in a way that we dont have to repeat the business logic (ofcourse I understand since it is related to file system, some code will differ from platform to platform).
Any ideas on how to implement it? Is C/C++ the only option. We dont want to use Java.
Thanks,
Pranz
yea, pick a common language for the logic first. Punting down in to C/C++ pretty much eliminates any of the real values to development that the Python and C# languages provide. Done write, MOST of your logic will be "Business Logic" with the rest glue to external services (i.e. databases, etc.).
So, you should pick a portable environment from the get go. Dropping down to C/C++ and linking it in is a viable alternative, but most likely not worth the time.
Mono is an option you'll probably want to look into.
Quote from the site for easy explanation:
Mono is a software platform designed to allow developers to easily create cross platform applications. Sponsored by Novell, Mono is an open source implementation of Microsoft's .NET Framework based on the ECMA standards for C# and the Common Language Runtime. A growing family of solutions and an active and enthusiastic contributing community is helping position Mono to become the leading choice for development of Linux applications.
Either use Mono or Python.
Mono allows you to run C# .NET code on both platforms. Python can be executed on both platforms already.
Qt has cross-platform libraries for all sorts of things, including UI and file system. It does, however, use C++.