altos/scheme: Add start/end args to vector->list

[fw/altos] / src / scheme / ao_scheme_builtin.c

diff --git a/src/scheme/ao_scheme_builtin.c b/src/scheme/ao_scheme_builtin.c
index e2532c98746a331ae248ace4f825ab41c4d1d874..0da68778eef7398164644e461d3bb3cbe93bd910 100644 (file)
--- a/src/scheme/ao_scheme_builtin.c
+++ b/src/scheme/ao_scheme_builtin.c
@@ -105,17 +105,23 @@ ao_scheme_check_argc(ao_poly name, struct ao_scheme_cons *cons, int min, int max
        return _ao_scheme_bool_true;
 }
 
-ao_poly
-ao_scheme_arg(struct ao_scheme_cons *cons, int argc)
+static ao_poly
+ao_scheme_opt_arg(struct ao_scheme_cons *cons, int argc, ao_poly def)
 {
-       if (!cons)
-               return AO_SCHEME_NIL;
-       while (argc--) {
+       for (;;) {
                if (!cons)
-                       return AO_SCHEME_NIL;
+                       return def;
+               if (argc == 0)
+                       return cons->car;
                cons = ao_scheme_cons_cdr(cons);
+               argc--;
        }
-       return cons->car;
+}
+
+ao_poly
+ao_scheme_arg(struct ao_scheme_cons *cons, int argc)
+{
+       return ao_scheme_opt_arg(cons, argc, AO_SCHEME_NIL);
 }
 
 ao_poly
@@ -140,6 +146,18 @@ ao_scheme_arg_int(ao_poly name, struct ao_scheme_cons *cons, int argc)
        return i;
 }
 
+static int32_t
+ao_scheme_opt_arg_int(ao_poly name, struct ao_scheme_cons *cons, int argc, int def)
+{
+       ao_poly         p = ao_scheme_opt_arg(cons, argc, ao_scheme_int_poly(def));
+       bool            fail = false;
+       int32_t         i = ao_scheme_poly_integer(p, &fail);
+
+       if (fail)
+               (void) ao_scheme_error(AO_SCHEME_INVALID, "%v: arg %d invalid type %v", name, argc, p);
+       return i;
+}
+
 ao_poly
 ao_scheme_do_car(struct ao_scheme_cons *cons)
 {
@@ -1120,11 +1138,21 @@ ao_scheme_do_list_to_vector(struct ao_scheme_cons *cons)
 ao_poly
 ao_scheme_do_vector_to_list(struct ao_scheme_cons *cons)
 {
-       if (!ao_scheme_check_argc(_ao_scheme_atom_vector2d3elist, cons, 1, 1))
+       int     start, end;
+
+       if (!ao_scheme_check_argc(_ao_scheme_atom_vector2d3elist, cons, 1, 3))
                return AO_SCHEME_NIL;
        if (!ao_scheme_check_argt(_ao_scheme_atom_vector2d3elist, cons, 0, AO_SCHEME_VECTOR, 0))
                return AO_SCHEME_NIL;
-       return ao_scheme_cons_poly(ao_scheme_vector_to_list(ao_scheme_poly_vector(ao_scheme_arg(cons, 0))));
+       start = ao_scheme_opt_arg_int(_ao_scheme_atom_vector2d3elist, cons, 1, ao_scheme_int_poly(0));
+       if (ao_scheme_exception)
+               return AO_SCHEME_NIL;
+       end = ao_scheme_opt_arg_int(_ao_scheme_atom_vector2d3elist, cons, 2, ao_scheme_int_poly(-1));
+       if (ao_scheme_exception)
+               return AO_SCHEME_NIL;
+       return ao_scheme_cons_poly(ao_scheme_vector_to_list(ao_scheme_poly_vector(ao_scheme_arg(cons, 0)),
+                                                           start,
+                                                           end));
 }
 
 ao_poly