Added enif_get_reverse_list to nif API

1 files changed, 24 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 68421b4387..d1afeb4f03 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -1007,6 +1007,30 @@ void enif_system_info(ErlNifSysInfo *sip, size_t si_size)
     driver_system_info(sip, si_size);
 }
 
+int enif_get_reverse_list(ErlNifEnv* env, ERL_NIF_TERM term, ERL_NIF_TERM *list) {
+    Eterm *listptr, *ret, *hp;
+
+    if (is_nil(term)) {
+	*list = term;
+        return 1;
+    }
+
+    ret = alloc_heap(env, 2);
+    *ret = NIL;
+
+    while (is_not_nil(term)) {
+	if (is_not_list(term)) {
+	    return 0;
+	}
+	hp = alloc_heap(env, 2);
+	listptr = list_val(term);
+	*ret = CONS(hp, CAR(listptr), *ret);
+	term = CDR(listptr);
+    }
+    *list = *ret;
+    return 1;
+}
+
 
 ErlNifMutex* enif_mutex_create(char *name) { return erl_drv_mutex_create(name); }
 void enif_mutex_destroy(ErlNifMutex *mtx) {  erl_drv_mutex_destroy(mtx); }