Add a function to duplicate objects

1 files changed, 34 insertions, 0 deletions

diff --git a/src/bootstrap/objects.c b/src/bootstrap/objects.c
index 497a04d..fd76166 100644
--- a/src/bootstrap/objects.c
+++ b/src/bootstrap/objects.c
@@ -111,6 +111,40 @@ append_string(Object *obj, const StringView sv) {
     obj->string_n += sv.n;
 }
 
+Object *
+obj_duplicate(Object *obj) {
+    Object *copy = obj_err;
+    switch (obj->type) {
+        case OBJ_TYPE_BOOL:
+        case OBJ_TYPE_NIL:
+        case OBJ_TYPE_PROCEDURE:
+        case OBJ_TYPE_ERR: {
+            copy = obj;
+        } break;
+        case OBJ_TYPE_FIXNUM: {
+            copy = make_fixnum(obj->fixnum);
+        } break;
+        case OBJ_TYPE_SYMBOL: {
+            copy = make_symbol((StringView){obj->symbol, obj->symbol_n});
+        } break;
+        case OBJ_TYPE_STRING: {
+            copy = make_string();
+            append_string(copy, (StringView){obj->string, obj->string_n});
+        } break;
+        case OBJ_TYPE_PAIR: {
+            Object *root = make_pair(obj_duplicate(obj->car), obj_nil);
+            copy = root;
+            obj = obj->cdr;
+            while (obj != obj_nil) {
+                root->cdr = make_pair(obj_duplicate(obj->car), obj_nil);
+                root = root->cdr;
+                obj = obj->cdr;
+            }
+        } break;
+    }
+    return copy;
+}
+
 void
 free_objects(Object *root) {
     switch (root->type) {