c_gtk_source_search_context_backward

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
__gshared extern (C)
int function(GtkSourceSearchContext* search, GtkTextIter* iter, GtkTextIter* matchStart, GtkTextIter* matchEnd, int* hasWrappedAround) c_gtk_source_search_context_backward;

Meta