Important Design Considerations

 Now that we have the technical pitfalls out the way, I would like to
 cover a couple design issues that I think will help in writing C UDFs
 for use with Clipper.

 The goal is to isolate the Clipper Extend System interface and Memory
 allocation routines in the C function.  This allows you to design the
 C function so that it can be compiled as a Clipper UDF or as a stand
 alone C program.  This will greatly improve the flexibility of the
 function and aids the debugging process as well.  We will use a
 #define to create a manifest constant for use as a flag that will be
 tested with #ifdef and #ifundef compiler directives, to optionally
 compile different parts of the code.

 For example:

 #define IS_CLIPPER

 #ifdef IS_CLIPPER

    <Some Clipper related code>

 #else

    <C code that emulates the Clipper code above>

 #endif