##       Software from the book "Inferno Programming with Limbo"#       published by John Wiley & Sons, January 2003.##       p. Stanley-Marbell <pip@gemusehaken.org>#implement Filter; include "sys.m";include "string.m";include "styx.m";include "filter.m"; sys : Sys;styx : Styx;str : String;Smsg : import styx; init(nil, nil : array of ref Sys->FD){	sys = load Sys Sys->PATH; 	styx = load Styx Styx->PATH;	if (styx == nil)	{		sys->raise(sys->sprint("fail:Could not load %s : %r",				Styx->PATH));	} 	str = load String String->PATH;	if (styx == nil)	{		sys->raise(sys->sprint("fail:Could not load %s : %r",				String->PATH));	} 	filtername = "Canon Filter : Canonicalizes file names with whitespace.";} rewrite(fmsg : ref Filtermsg){	newlist : list of ref Sys->Dir; 	if (fmsg.styxmsg.mtype == Styx->Rstat)	{		direntry := styx->convM2D(fmsg.styxmsg.stat);		canondir(direntry);		fmsg.styxmsg.stat = styx->convD2M(direntry);	} 	if (fmsg.styxmsg.mtype == Styx->Twalk)	{		fmsg.styxmsg.name = decanon(fmsg.styxmsg.name);	} 	if (fmsg.isdirread && (len fmsg.dirlist > 0))	{		while (fmsg.dirlist != nil)		{			item := hd fmsg.dirlist;			canondir(item);			newlist = item :: newlist; 			fmsg.dirlist = tl fmsg.dirlist;		} 		fmsg.dirlist = newlist;	}	} canondir(item : ref Sys->Dir){	#	BUG : should also cater for long filenames,	#	with possible identical stems	for (i := 0; i < len (*item).name; i++)	{		if ((*item).name[i] == ' ')		{			(*item).name[i] = '?';		}	}} decanon(name : string) : string{	#	BUG : this reversion should only happen for	#	files that we canonicalized in the first place	for (i := 0; i < len name; i++)	{		if (name[i] == '?')		{			name[i] = ' ';		}	} 	return name;}