+/* Exclude values for notmuch_query_set_omit_excluded */
+typedef enum {
+ NOTMUCH_EXCLUDE_FALSE,
+ NOTMUCH_EXCLUDE_TRUE,
+ NOTMUCH_EXCLUDE_ALL
+} notmuch_exclude_t;
+
+/* Specify whether to omit excluded results or simply flag them. By
+ * default, this is set to TRUE.
+ *
+ * If set to TRUE or ALL, notmuch_query_search_messages will omit excluded
+ * messages from the results, and notmuch_query_search_threads will omit
+ * threads that match only in excluded messages. If set to TRUE,
+ * notmuch_query_search_threads will include all messages in threads that
+ * match in at least one non-excluded message. Otherwise, if set to ALL,
+ * notmuch_query_search_threads will omit excluded messages from all threads.
+ *
+ * The performance difference when calling
+ * notmuch_query_search_messages should be relatively small (and both
+ * should be very fast). However, in some cases,
+ * notmuch_query_search_threads is very much faster when omitting
+ * excluded messages as it does not need to construct the threads that
+ * only match in excluded messages.
+ */
+void
+notmuch_query_set_omit_excluded (notmuch_query_t *query,
+ notmuch_exclude_t omit_excluded);
+