Last updated: 27-06-2008

Visual Prolog Frequently Asked Questions (FAQ)

Q: How to get started with Visual Prolog?

A: Start by reading Getting Started with Visual Prolog.

Q: Can I compile my Visual Prolog 5.x program in the current version of Visual Prolog?

A: No, the current version of Visual Prolog is not backwards compatible with Visual Prolog 5.x.  The syntax has been changed in certain respects, and all Visual Prolog code must be in classes.  But Visual Prolog  contains backwards-libraries that have almost identical interface and behavior.

Prolog Development Center has released the migration tool that can assist in migrating code from Visual Prolog 5.

Q: Which platforms does Visual Prolog support?

A: Visual Prolog  supports  Windows/NT4/2000/XP/Vista. 

There are no plans for supporting Linux or any Unix platforms.

Q: What are the differences between Visual Prolog and traditional Prolog?

A: The differences between traditional Prolog and Visual Prolog can be broadly divided into these categories:

1. Program structure differences
   There are distinct, yet easy to understand differences between the structure used in traditional Prolog and that used in Visual Prolog. It essentially comprises of understanding how to mark out the declarations from the definitions, and to indicate the main Goal that the program has to seek using specific keywords.
2. File considerations
   Visual Prolog gives various facilities to organize the structure of the program into different kinds of files.
3. Scope access issues
   A Visual Prolog program can pick up functionality developed in other modules using a concept called scope identification.
4. Object orientation
   A Visual Prolog program can be written as an object-oriented program, using classic object oriented features.

Q: Where can I find examples and demos?

A: Visual Prolog examples and demost are available in several ways:

1. Visual Prolog disctribution includes sample projects  that can be installed from the Integrated Development Environment (IDE) with the help of the command Help |  Install Examples.
    
2. This site contains examples provided by the Prolog Development Center (PDC) and members of Visual Prolog Community.
    
3. Visual Prolog tutorials discuss examples that might be downloaded. You will be suggested to download source files while reading these tutorials.
   For example, the tutorials "Fundamental Prolog" and "Fundamental Visual Prolog" discuss a well-known prolog family example in details.

Q: How do I make and use COM objects?

A: Visual Prolog is COM compatible, the IDE can generate necessary wrap classes and interfaces based on a type library supplied with the COM object.

Please read the tutorial.

Q: Does the current version of Visual Prolog include the Help Maker from Visual Prolog 5.x?

A: No. Visual Prolog 5.2 Help Maker provided creating Help systems in WinHelp format (.hlp) that is outdated now.

To create Help systems for Visual Prolog  applications, please, use MS Help Workshop or third-party tools that create Help systems in MS HTML Help format (.chm) or other modern Help formats.

Q: Is it possible to use a DLL, created by Visual Prolog, in a Microsoft.NET project?

A: Yes. It is possible. Such DLL created by Visual Prolog  should have predicates exported with stdcall calling convention. And VB.NET or C#.NET code should call it in the same manner as invocation of an API function.

You are welcome to download How to Use Visual Prolog DLL from .Net example that creates a Visual Prolog DLL and shows how a program, created by Visual Basic .NET, can call a predicate, exported by this DLL.

Q: Can I use my registration in the Discussion Forum to have Registered Visual Prolog Personal Edition and vice versa?

A: No. Registration in the Discussion Forum and registration of Visual Prolog Personal Edition are two different registrations.

To register your Personal Edition you need to use the WEB | Register menu item in the Integrated Development Environment (IDE).