libyang REFACTOR avoid constant literals
Improve readability of the code.
Includes also unification of "no break in the case" comment to "fall
through".
diff --git a/src/tree_data_internal.h b/src/tree_data_internal.h
index bb8e27a..f4de881 100644
--- a/src/tree_data_internal.h
+++ b/src/tree_data_internal.h
@@ -26,6 +26,13 @@
struct ly_path_predicate;
struct lysc_module;
+#define LY_XML_SUFFIX ".xml"
+#define LY_XML_SUFFIX_LEN 4
+#define LY_JSON_SUFFIX ".json"
+#define LY_JSON_SUFFIX_LEN 5
+#define LY_LYB_SUFFIX ".lyb"
+#define LY_LYB_SUFFIX_LEN 4
+
/**
* @brief Internal data parser flags.
*/