The RNA folding grammar

The RNA folding grammar as implemented in RNAlib.
// typedefs

typedef void () vrna_callback_gr_rule_aux (
    vrna_fold_compound_t *vc,
    int i,
    int j,
    void *data
    )

typedef void () vrna_callback_gr_free_auxdata (void *data)
typedef struct vrna_gr_aux_s vrna_gr_aux_t

// structs

struct vrna_gr_aux_s