Add optional, variadic arguments
diff --git a/src/lisp/lib/std.c b/src/lisp/lib/std.c
index c7efca0..3681e47 100644
--- a/src/lisp/lib/std.c
+++ b/src/lisp/lib/std.c
@@ -52,34 +52,57 @@
return call_list_closure((struct closure *)(func ^ CLOSURE_TAG), args);
}
-void add_function(struct environment *env, char *name, void *func, int nargs, enum namespace ns)
+value_t l_nilp(value_t val)
+{
+ return nilp(val) ? t : nil;
+}
+
+void add_function(struct environment *env, char *name, void *func, struct args *args, enum namespace ns)
{
struct function *last, *new = malloc(sizeof(struct function));
last = env->first;
new->prev = last;
new->name = name;
- new->nargs = nargs;
+ new->args = args;
new->code_ptr = func;
new->namespace = ns;
env->first = new;
}
+void add_c_function(struct environment *env, char *name, void *func, int nargs)
+{
+ struct args *args = new_args();
+ args->num_required = nargs;
+
+ add_function(env, name, func, args, NS_FUNCTION);
+}
+
+value_t l_elt(value_t seq, value_t i)
+{
+ if (!listp(seq) || !integerp(i))
+ return nil;
+
+ return elt(seq, i >> 2);
+}
+
void load_std(struct environment *env)
{
- add_function(env, "+", l_plus, 2, NS_FUNCTION);
- add_function(env, "-", l_minus, 2, NS_FUNCTION);
- add_function(env, "*", l_times, 2, NS_FUNCTION);
- add_function(env, "/", l_divide, 2, NS_FUNCTION);
+ add_c_function(env, "+", l_plus, 2);
+ add_c_function(env, "-", l_minus, 2);
+ add_c_function(env, "*", l_times, 2);
+ add_c_function(env, "/", l_divide, 2);
- add_function(env, "car", car, 1, NS_FUNCTION);
- add_function(env, "cdr", cdr, 1, NS_FUNCTION);
- add_function(env, "cons", cons, 2, NS_FUNCTION);
+ add_c_function(env, "car", car, 1);
+ add_c_function(env, "cdr", cdr, 1);
+ add_c_function(env, "cons", cons, 2);
- add_function(env, "print", l_printval, 1, NS_FUNCTION);
+ add_c_function(env, "print", l_printval, 1);
+ add_c_function(env, "apply", l_apply, 2);
- add_function(env, "apply", l_apply, 2, NS_FUNCTION);
+ add_c_function(env, "nilp", l_nilp, 1);
+ add_c_function(env, "elt", l_elt, 2);
if (!load_library(env, "std"))
{
diff --git a/src/lisp/lib/std.h b/src/lisp/lib/std.h
index a117b5d..dae0ac3 100644
--- a/src/lisp/lib/std.h
+++ b/src/lisp/lib/std.h
@@ -6,6 +6,7 @@
value_t l_plus(value_t a, value_t b);
value_t l_printval(value_t val);
-void add_function(struct environment *env, char *name, void *func, int nargs, enum namespace ns);
+void add_function(struct environment *env, char *name, void *func, struct args *args, enum namespace ns);
+void add_c_function(struct environment *env, char *name, void *func, int nargs);
void load_std(struct environment *env);
bool load_library(struct environment *env, char *name);