X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=filter.h;h=0bd546903927d412fccef946cf8f43783ed8bc70;hp=937bb42bc610e65d371ff8787a6e701c240c558a;hb=53d5ac455d0616a5ee8867c986631ed34c177a42;hpb=a13a1e0d202a8969374b9a70562556e689597f2d

diff --git a/filter.h b/filter.h
index 937bb42b..0bd54690 100644
--- a/filter.h
+++ b/filter.h
@@ -58,17 +58,18 @@ struct filter {
 	/**
 	 * Open one instance of this filter.
 	 *
-	 * This should allocate the output buffer of the given filter node and do any
-	 * other filter-specific preparations like initializing the private_data member
-	 * of \a fn suitably. The open function is assumed to succeed.
+	 * This should allocate the output buffer of the given filter node and
+	 * do any other filter-specific preparations like initializing the
+	 * private_data member of \a fn suitably. The open function is
+	 * optional, If it is provided, it is assumed to succeed.
 	 */
 	void (*open)(struct filter_node *fn);
 	/**
 	 * Close one instance of this filter.
 	 *
-	 * Free all resources of associated with \a fn that were previously allocated
-	 * by the open() function. It's OK to leave this alone if the filter does not
-	 * need any cleanups.
+	 * Free all resources associated with \a fn that were previously
+	 * allocated by the open() function. It's OK to set this to NULL if the
+	 * filter does not need to perform any cleanup operation.
 	 */
 	void (*close)(struct filter_node *fn);
 	/**