altos/scheme: add list-copy

A lot easier as a built-in; the obvious scheme version is recursive.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/scheme/ao_scheme.h b/src/scheme/ao_scheme.h
index 4655b2a9..2fa1ed60 100644
--- a/src/scheme/ao_scheme.h
+++ b/src/scheme/ao_scheme.h
@@ -634,6 +634,9 @@ ao_scheme_cons_display(ao_poly);
 int
 ao_scheme_cons_length(struct ao_scheme_cons *cons);
 
+struct ao_scheme_cons *
+ao_scheme_cons_copy(struct ao_scheme_cons *cons);
+
 /* string */
 extern const struct ao_scheme_type ao_scheme_string_type;