diff options
Diffstat (limited to 'src/lisp/ao_lisp_cons.c')
| -rw-r--r-- | src/lisp/ao_lisp_cons.c | 13 |
1 files changed, 13 insertions, 0 deletions
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) { |