+_Bool graph_matches_ident (graph_config_t *cfg, const graph_ident_t *ident);
+
+/* Compares the given string with the appropriate field of the selector. If the
+ * selector field is "/all/" or "/any/", returns true without checking the
+ * instances. See "graph_inst_search_field" for finding all matching instances.
+ * */
+_Bool graph_matches_field (graph_config_t *cfg,
+ graph_ident_field_t field, const char *field_value);
+
+int graph_inst_foreach (graph_config_t *cfg,
+ inst_callback_t cb, void *user_data);
+
+graph_instance_t *graph_inst_find_exact (graph_config_t *cfg,
+ graph_ident_t *ident);
+
+graph_instance_t *graph_inst_find_matching (graph_config_t *cfg,
+ const graph_ident_t *ident);
+
+int graph_inst_search (graph_config_t *cfg, const char *term,
+ graph_inst_callback_t callback, void *user_data);