Visual Prolog 6.2 Final Release  Upgrade Notes

• Upgrade Discounts
• Top Reasons to upgrade Visual Prolog 6.2
• Upgrading from Visual Prolog 6.1 to Visual Prolog 6.2
• Upgrading from Visual Prolog 5.x to Visual Prolog 6.2

See also

• New Features in Visual Prolog 6.2

Upgrade Discounts

• Owners of Visual Prolog 6.1 Commercial Edition license are welcome to order Visual Prolog 6.2 with a discount (50%, or depending on a number of licenses).
• A free upgrade is available for the users, who purchased the Commercial Edition license after September 1, 2004.
• Customers with the licenses earlier than Visual Prolog 6.1 are no longer eligible for upgrade discounts when purchasing the current version.

To check whether your are eligible for upgrade discounts and to order Visual Prolog 6.2 Commercial Edition with an appropriate discount, please, use WEB|Check For Update menu item from your Visual Prolog 6.1 Visual Development Environment (VDE).

Upgrading from Visual Prolog 6.1 to Visual Prolog 6.2.

1. By default, Visual Prolog 6.2 replaces Visual Prolog 6.1 while installation. If you want to preserve Visual Prolog 6.1 at your computer, install Visual Prolog 6.2 into a different location.
2. Visual Prolog 6.2 projects are not fully backward-compatible.
   Visual Prolog 6.1 VDE won't allow to open projects modified by Visual Prolog 6.2 VDE.
   It is recommended to create a backup copy of your project before opening it by the Visual Prolog 6.2 VDE.
3. If you are going to use Visual Prolog 6.1 and Visual Prolog 6.2 simultaneously at the same computer, it is recommended to switch the VDE setting "Open the Last Project at Start Up" OFF, because the VDE in the both versions use the same registry entries for the list of opened projects.
4. It is recommended to remove the Read-Only flag from a project file before the first build.

5. Your Visual Prolog code developed with Visual Prolog 6.1 will be compatible with the Visual Prolog 6.2 in the most cases.
   However, enhancements implemented in Visual Prolog 6.2 require some updates:

   1. Predicates div and mod has changed their sense.
      In Visual Prolog 6.1

   -1 = -5 div 3
   -2 = -5 mod 3

   In Visual Prolog 6.2

   -2 = -5 div 3
   +1 = -5 mod 3

   So, each file that contains div or mod should be checked, whether it works correctly.

   The simplest solution is to replace:

   div => quot
   mod => rem

   for ALL source files.

   2. The format of specifying a fully-qualified (i.e. with an arity) predicate with a return value in resolve/delegate predicates from qualifications has been changed:

   predicateName//N => predicateName/N->

   This might cause error messages while building your project in Visual Prolog 6.2.
   Fix these errors to develop you project in Visual Prolog 6.2.

Upgrading from Visual Prolog 5.x to Visual Prolog 6.2

Prolog Development Center provides the Migration Tool that will assist you to migrate your Visual Prolog 5.x projects into Visual Prolog 6.2.

The Migration Tool is now available for migrating Visual Prolog 5x projects directly into Visual Prolog 6.2.

You are welcome to download the Migration Tool for free with the help of the WEB|Check for Update menu item in the VDE.
Note that the Migration Tool available from Visual Prolog 6.1 will migrate projects into Visual Prolog 6.1. You need to install Visual Prolog 6.2 to download Visual Prolog 6.2 - specific tool.

The tool is also supplied with a a CD version of the Commercial Edition of Visual Prolog 6.2.