fix bug in apply, improve printing

1 files changed, 11 insertions, 6 deletions

diff --git a/lisp.c b/lisp.c
index 22e90b5..da0a5f6 100644
--- a/lisp.c
+++ b/lisp.c
@@ -265,21 +265,26 @@ value *eval_pair(env *e, value *v) {
 	}
 
 	if (head_eval->type == VT_LAMBDA) {
-		return apply(head_eval, tail);
+		return apply(e, head_eval, tail);
 	}
 
 	return v;
 }
 
-value *apply(value *lval, value *args) {
-	env *sub_env = env_create(lval->as.lambda.env);
+value *apply(env *e, value *lval, value *args) {
+	env *sub_env = env_create(e);
 	value *params = lval->as.lambda.params;
 	value *arg = args;
 
 	while (params->type == VT_PAIR && arg->type == VT_PAIR) {
-		env_define(sub_env,
-			   car(params)->as.sym,
-			   eval(lval->as.lambda.env, car(arg)));
+		if (car(params)->type != VT_SYMBOL) {
+			printf("not a symbol: ");
+			println_value(car(params));
+			return make_nil();
+		}
+
+		value *arg_eval = eval(e, car(arg));
+		env_define(sub_env, car(params)->as.sym, arg_eval);
 		params = cdr(params);
 		arg = cdr(arg);
 	}