##       Software from the book "Inferno Programming with Limbo"#       published by John Wiley & Sons, January 2003.##       p. Stanley-Marbell <pip@gemusehaken.org>#Filter : module{	filtername : string; 	Filtermsg : adt	{		styxmsg		: ref Styx->Smsg;		isdirread	: int;		dirlist		: list of ref Sys->Dir;	}; 	rewrite	: fn(msg : ref Filtermsg);	init	: fn(exportfd, mountfd : array of ref Sys->FD);};