User-Defined Functions for indexes

How can I create a User-Defined Function (UDF) for my index file? I have one in the files for the Clipper application I am porting to Delphi.

Halcyon 6 already contains most of the common index functions, but there will always be a requirement for unique functions.

You can create a unit that handles your user-defined functions for expressions in gs6_sql. It should be formatted like this example unit.

Place your unit name in the Uses clause of your project to implement. However, you will not be able to use the index in DesignTime, since your UDF will not be in the DesignTime library. To be able to use your UDFs at DesignTime, go into the package editor and add the unit, then compile and install.

You will want to create your own unit name so that it will not be overwritten by future installs. Any valid unit name is ok as long as you use it consistently in your projects and in the package editor.