FlagShip Offers You Full C Access

FlagShip Offers You Full C Access

Beside the prg language (Xbase syntax), FlagShip offers you full access to programs and functions written in the C language. There are three different API's for that reason (all described in detail in the manual):

1. Open C API, supporting vice-versa access of linked in C functions. This API also allows you to include inline C code directly in the prg source. You may even access all of the functionality of your system libraries, e.g:

** File: myprog.prg
STATIC pi := 3.14        && supports standard Clipper var types
LOCAL  myvar AS double   && but also typed variables
myvar = pi / 6.0
#Cinline
   myvar = sin(myvar);   /* access to std. C lib */
#endCinline 
? myvar                  // prints 0.50

Why the above wording, "in extreme cases?" You need approximately 10 to 25 times more source lines in C (and the same amount of additional debugging effort) than in the .prg language. Normally, only modules that require special handling, library access or need compatibility with external modules (real-time events, 3rd party C libraries, Java scripts and so on) are written in C.

2. Extend C API is compatible with Clipper (Summer '87 to 5.2 and 5.3.) So, if your available source already uses this interface, you probably won't need to change them.

** File: myprog.prg
  ? sinus (179.53)         // print the sinus of 179.53 degree

  /* File: sinus.c */
  #ifdef FlagShip           /* FlagShip vs. Clipper usage */
  # include "FSextend.h"
     FSudfname (sinus)      /* FlagShip Extend API syntax */
  #else                     /* for Clipper */
  # include "extend.h"      /* or extend.api */
  # define FSreturn return;
  # define FSinit()
     CLIPPER SINUS()        /* Clipper Extend API Syntax */
  #endif
  {
     double degree, retval = 0.0;
     FSinit();                    /* init parameter stack         */
     if (PCOUNT == 1 && ISNUM(1)) /* check received parameter(s)  */
     {
       degree = _parnd (1);       /* get 1st paramater as double  */
       retval = sin(3.141592 * degree / 180.0);
     }
     _retnd (retval);             /* pass the value back          */
     FSreturn;
   }

3. Modification of the produced C source.

Additional, detailed information is available in the on-line and printed FlagShip manual (section EXT.)