Calling YAP from C# code

public void Consult( String strFileName )

{

String strCommand = String.Format( "consult('{0}')", strFileName );

int term = 0;

int goal = YAPWrapper.YAP_ReadBuffer( strCommand, ref term );

int result = YAPWrapper.YAP_RunGoal( goal );

if ( result == 0 )

{

throw new ArgumentException( "Error while trying to consult file " + strFileName );

}

I always get a 0 result from calling YAP_RunGoal. Any ideas why? Is there any way to figure out why running a goal doesn't work? (Any GetLastError function?) Note that I've tried various possibilities with the file name: full path with or without the extension, just the filename again with or without the extension etc.

I suspected that this could be because I'm using P/Invoke to call YAP functions, so I tried linking directly to YAP, but in order to do that I need a .lib file to link against. I could not find it in the download, so I tried building YAP from the instructions given, only using VS2008 instead of VS 6.0. But every time I run that version, I get an error saying that I'm trying to access protected memory, and this happens with the first function I'm calling (YAP_FastInit).

Finally, I tried calling the YAP function directly using ::LoadLibrary( "yap.dll" ) and ::GetProcAddress( hLib, "YAP_FastInit"), but the program I wrote that does that (a simple console program in C++), simply crashes without any warning whatsoever when I try this.

So, are there any ideas on how I can call YAP from a C# program?

Daníel