D .dll Calling Pascal .dll - Pascal Files
Parsing Command Line Parameters Processing

The Pascal backend of D .dll Calling Free Pascal .dll - D Files.

In both Lazarus and Object Pascal the command line parameters are available via a call to function ParamStr (index), which returns the indexth
command line parameter as a string (it can be returned to a char array variable). ParamStr (0) = the program's name.  In D, the entire command
line parameters are accessible by a single char*.

The Pascal .dll (allazrs.dll) consists of one Object Pascal file, one Lazarus unit, and LCL units. The procedures and functions in allazrs.dll have
been successfully called by both a Free Pascal Windows program and a D .dll.
Requires both Free Pascal (for ALlazrs.pas) and Lazarus (for NumRecGlbl.pas and Interfaces.ppu).

Pascal Files:

1. ALlazrs.pas - originally developed for software reuse of user written unit NumRecGlbl's command line parameter (ParamStr (i)

   and ParamCount) processing, as well as mapping a 1 dimensional array to a 2 dimensional matrix, in a Free Pascal Windows program.  In this application LIBRARY ALlazrs procedure DCMDLINE (...) is called by D module CmdLine procedure callDCMDLINE (...) as part of D Windows program command line parameter processing. allazrs.dll - ALlazrs.pas dynamic link library, compiled with a modified fpcdll.bat (see below) allazrs.lib - allazrs.dll

   import library (not used for Pascal applications, required for D applications - used when linking the D .dll in the D module's
   pragma (lib, "ALlazrs.lib") statement), built using Digital Mars implib utility (file bup.zip).
   
   units Windows and LCLType (used by Interfaces) both define a Window Handle type HWnd. Windows.HWnd is compatible with both D
   and Object Pascal.
   
   
2. Interfaces.ppu - Lazarus Component Library (LCL) component unit description file; required for useing Lazarus unit NumRecGlbl in
   Object Pascal LIBRARY ALlazrs.  (In LIBRARY ALlazrs, recommend explicitly defining HWnd handles as either type Windows.HWnd
   or type LCLType.HWnd)
   
   
3. NumRecGlbl.pas - Numerical Recipes¹ secondary unit used in Lazarus project Lazarus, Free Pascal, Silverfrost FTN95, and Numerical Recipes;

   contains command line parameter processing, file validation (when file name included in command line parameters) using the Dos unit, and indices mapping for a 1 dimensional array to/from a TStringGrid, adapted for use via allazrs.dll in a Free Pascal Windows application. numrecglbl.ppu - NumRecGlbl.pas unit description file. genetyp.inc2 - include file developed from major rewrite of Dawkins8 Biomorphs2 (Free Pascal dawkins8.dll callable from both Pascal and D programs); contains useful CONSTant and TYPE declarations nrtyp.inc - Numerical Recipes include file

   
   
4. hwndio.dll - used in Free Pascal Windows programs, not used in D .dll Calling Free Pascal .dll - D Files; hwndio.pas dynamic link library;
   collection of Free Pascal general purpose functions for Windows Edit Controls I/O, field tabbing.

DCMDLINE (...)

Procedure name must be upper case to be D callable. Constants, variable iErr, functions CurParamSwitch (...) and cmdLnFname (...) defined in Lazarus unit NumRecGlbl. Call LIBRARY ALlazrs procedure DCMDLINE (...) to search for/process input file parameter or artificial life related arguments. D module CmdLine procedure prcCmdLine (...) extracts a command line parameter from the char* command line parameters list passed to the D main program by Windows, and saves it in a character array.  (prcCmdLine (...) is primarilarly used for artificial life/simulated annealing applications.) prcCmdLine (...) calls D module CmdLine procedure callDCMDLINE (...) (may call other procedures as well). callDCMDLINE (...) calls DCMDLINE (...) (examining the source code may help to explain why done this way)

Pascal Compiling/Linking:
1. In addition to the -WR switch, fpcdll.bat will also need the following switches:
   -FuD:\lazarus\lcl\units\i386-win32
   -FuD:\lazarus\lcl\units\i386-win32\win32
   -FuD:\lazarus\components\lazutils\lib\i386-win32

   (the above values reflect my Lazarus installation, which is on the D: drive, \lazarus directory; be sure to adjust the additional switches to reflect your installation) To compile ALlazrs.pas and its associated files into allazrs.dll, open a D2 32-bit Command Prompt and type: fpcdll ALlazrs (Can safely leave above additional switches in fpcdll.bat if the Object Pascal

   Library does not need them; or can write another batch file, lcldll.bat for example, which passes the above switches along with the
   source file name to fpcdll.bat.)
   
   
2. To build allazrs.lib, in the same D2 32-bit Command Prompt, type:
   implib allazrs.lib allazrs.dll

1. Press, William H., Brian P. Flannery, Saul A Teukolsky, and William T. Vetterling (1986). Numerical Recipes: The Art of Scientific Computing.
New York:Press Syndicate of the University of Cambridge.
2. Rietman, Edward (1994). Genesis Redux: Experiments Creating Artificial Life. Windcrest (McGraw-Hill).
The original Dawkins8 source consisted of one unit and one MS-DOS main program (without any modularity whatsoever). Broke that down into two
Windows callable .dll's (genecode.dll and dawkins8.dll) and one include file. The main .dll is now very modular.