Advanced Programming Guide

char * concat( char* a, char *b ){char *r;if( !a || !b ) return( NULL );7.2 Using Compiled Code in Maple • 313r = (char*)malloc((strlen(a)+strlen(b)+1)*sizeof(char));strcpy(r,a);strcat(r,b);}return( r );Method 3: Customizing WrappersFor complete control over data conversions, Maple allows modification ofexisting wrappers and creation of custom wrappers. There are numerousC and Fortran functions available for translating and manipulating Mapledata structures.To use this method, you must be familiar with the steps required touse compiled code in Maple, described in Method 1: Calling ExternalFunctions on page 294. For this method, you do not declare a functionspecification because Maple passes one data structure containing allthe passed information. Therefore, there are only two basic steps (DLLcreation and function invocation as described on pages 295-296) in additionto wrapper generation. Wrappers were introduced in Method 2:Generating Wrappers on page 301.External Function Entry PointMaple finds the symbol name given as the first argument to define_externalin the DLL specified in the LIB= argument. Maple also finds theMWRAP_symbolName in the wrapper library. This MWRAP_symbolName functionprototype has the following format.ALGEB MWRAP_quadruple_it(MKernelVector kv,FLOAT32 (*fn) ( FLOAT32 a1 ),ALGEB fn_args);This prototype is taken from the wrapper quad.c described in theprevious section. The first argument kv is a handle to the Maple kernel