use "alloc"use "dir"use "option" pkg std =	type diriter = dir#	impl iterable diriter -> byte[:] 	const byentry	: (d : dir# -> diriter);; const byentry = {d	-> (d : diriter)} impl iterable diriter -> byte[:] =	__iternext__ = {itp, valp:nextfile		match dirread((itp# : dir#))		| `Some ".":	goto nextfile		| `Some "..":	goto nextfile		| `Some ent:			valp# = ent			-> true		| `None:			-> false		;;	} 	__iterfin__ = {itp, valp		std.slfree(valp#)	};;