X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=src%2Flisp%2Fao_lisp_cons.c;fp=src%2Flisp%2Fao_lisp_cons.c;h=c70aa1caa0f70dacc4e3c86cdcd74fdd62c58965;hb=6d2f271a45759bd792d299f04a424d3382ef4798;hp=9379597ca82eb88ed6ae2866f2a11358cb4d7f6e;hpb=12a1f6ad48f2b924f71239effeb90afca75a090f;p=fw%2Faltos

diff --git a/src/lisp/ao_lisp_cons.c b/src/lisp/ao_lisp_cons.c
index 9379597c..c70aa1ca 100644
--- a/src/lisp/ao_lisp_cons.c
+++ b/src/lisp/ao_lisp_cons.c
@@ -105,6 +105,19 @@ ao_lisp_cons_cons(ao_poly car, ao_poly cdr)
 	return cons;
 }
 
+struct ao_lisp_cons *
+ao_lisp_cons_cdr(struct ao_lisp_cons *cons)
+{
+	ao_poly	cdr = cons->cdr;
+	if (cdr == AO_LISP_NIL)
+		return NULL;
+	if (ao_lisp_poly_type(cdr) != AO_LISP_CONS) {
+		(void) ao_lisp_error(AO_LISP_INVALID, "improper list");
+		return NULL;
+	}
+	return ao_lisp_poly_cons(cdr);
+}
+
 ao_poly
 ao_lisp__cons(ao_poly car, ao_poly cdr)
 {