genetic programming in C++ Adam Fraser University Of Salford, Salford, M5 4WT, United Kingdom

				// function.cc
				
				//--------------------------------------------------------------------------
				// This code is a component of Genetic Programming in C++ (Version 0.40)
				// Copyright Adam P. Fraser, 1993,1994
				// This code is released for non-commercial use only.
				// For comments, improvements, additions (or even money !?) contact:
				// Adam Fraser, Postgraduate Section, Dept of Elec & Elec Eng,
				// Maxwell Building, University Of Salford, Salford, M5 4WT, United Kingdom.
				// Internet: a.fraser@eee.salford.ac.uk
				// Tel: (UK) 061 745 5000 x3633
				// Fax: (UK) 061 745 5999
				//--------------------------------------------------------------------------
				
				
				// Function Set system using C++ and all the ease of OOP programming
				// By Adam Fraser 07 March 93 -> 24 April 1994
				
				// The main block of code for using Function Set made up of to classes
				//  Function and FS (FunctionSet) is all very simple I hope...........
				// see documentation for more details.................................
				
				// RECENT IMPROVEMENTS
				
				// converted to using unsigned int's rather than char's as GNU C 2.5.8 doesn't
				// seem to like them very much and also will give me greater range if function
				// and terminal set increases over 256
				
				// include the class definitions of Function and FS
				#include "function.hpp"
				// definitions for random number generator
				#include "gprand.hpp"
				// definition for variable list system
				#include 
				// for memory allocations  
				#include  
				
				
				//  MAIN CODE START
				
				unsigned int function( Function* pf )
				{
					return pf->uiFunction;
				}
				
				unsigned int arguments( Function *pf)
				{
					return pf->uiArguments;
				}
				
				// The main block for Function Set creation reads in the number of functions
				// and a variable list (va_list) of these function values and their arguments
				//  for example...
				//                                      Function Set = new FS( 3, 1,2,3, 2,2,3 );
				// NB all values first and then their respective arguments !!!!! 
				FS::FS( unsigned int noofargs, ... )
				{
					va_list ap;                               // ap =  variable list
					Function *pf;
				
				// necessary for variable list to start it up.............................
					va_start( ap, noofargs );                      
				
				// why would anyone send 0 to function set creation but if they do return.
					if ( noofargs == 0 ) return;
				
				// allocate memory for the function set from the number of arguments......
					if ( !(pfHeader = (Function *)calloc( noofargs, sizeof( Function ) ) ) )
						ExitSystem( "FS::FS" );
				
				// set length of function set used in other functions and part of FS class
					uiLength = noofargs;
				
				// set pointer to function to the start before reading in values..........
					pf = pfHeader;                           
				
				// allocate all the function values from variable list....................
					for ( int i = 0; i < noofargs; i++, pf++ )
						pf->uiFunction = va_arg( ap, unsigned int );
				
				// reset pointer to function back to start for args.......................
					pf = pfHeader;
				
				// allocate all the function arguments from variable list.................
					for ( i = 0; i < noofargs; i++, pf++ )
						pf->uiArguments = va_arg( ap, unsigned int );    
				
				 // necessary to close variable list 
					va_end( ap );                            
				}
				
				// destructor for the function set........................................
				FS::~FS()
				{
				// if the function set exist and functions within this set exist free memory
					if ( this )     if ( pfHeader ) free( pfHeader );
				}
				
				// Up to the programmer to make sure n is below total length of function set
				Function* FS::Nth( unsigned int n )
				{
				// set a pointer to function to the start
					Function *pf= pfHeader;
				
				// move through the function set until n is reached.........................
					for ( unsigned int i = 1; i < n; i++, pf++ );
				
				//.... then return the function at this position............................
					return pf;
				}
				
				// This function would probably have been better written with loads of temp
				//  variables my software eng lecturer of yesteryear would not be happy...
				// Basically this chooses a value from the Function set... APF 7/03/93
				Function* FS::Choose()
				{
				// return a Nth member where N is a random number in the range 0 -> uiLength
					return ( Nth( ( gp_rand() %  uiLength ) + 1 ) );
				}
				
				
				// THIS NEXT SECTION OF CODE IS NOT USED WITHIN GPCPP BUT MAY BE HELPFUL
				// IF YOU WISH TO IMPROVE THE COMPLETE CODE 
				
				
				// Print functions... using ostream
				// Print out individual function & arguments.....
				ostream& operator 				{
					os 						 					return os;
				}
				
				// Prints out complete function set not particulartly useful for GP
				// but for debugging well it's the bees knees.....
				ostream& operator 				{
				// if a function set exists.......
					if ( pfs )
					{
				// set up function ptr to star and set up a length of function set variable
						Function *pf = pfs->pfHeader;
						unsigned int uil = pfs->uiLength;
				
				// move through the function set printing out each function in turn
						while ( uil-- ) os 					}
					return os;
				}
				
				// a standard constructor for Function (not used within gpcpp)
				Function::Function()
				{
					uiFunction = 0;
					uiArguments = 0;
				}
				
				// a standard constructor for FunctionSet (not used within gpcpp)
				FS::FS()
				{
					pfHeader = NULL;
				}
				
				// function.cc