hashmaps can now be printed and keys deleted

src/built_ins.cpp

@@ -848,6 +848,12 @@ proc load_built_ins_into_environment() -> void {
         hm_set(hm->value.hashMap, key, value);
         return Memory::nil;
     };
+    define((hash-map-delete! hm key), "TODO") {
+        fetch(hm, key);
+        try assert_type(hm,  Lisp_Object_Type::HashMap);
+        hm_delete_object(hm->value.hashMap, key);
+        return Memory::nil;
+    };
     define((vector . args), "TODO") {
         fetch(args);
         Lisp_Object* ret;

src/io.cpp

@@ -284,7 +284,15 @@ proc print(Lisp_Object* node, bool print_repr = false, FILE* file = stdout) -> v
     case (Lisp_Object_Type::Continuation): fputs("[continuation]", file);                               break;
     case (Lisp_Object_Type::CFunction):    fputs("[C-function]", file);                                 break;
     case (Lisp_Object_Type::Pointer):      fputs("[pointer]", file);                                    break;
-    case (Lisp_Object_Type::HashMap):      fputs("[hashmap]", file);                                    break;
+    case (Lisp_Object_Type::HashMap): {
+        for_lisp_obj_hash_map (node->value.hashMap) {
+            fputs(" ", file);
+            print(key, true, file);
+            fputs(" -> ", file);
+            print((Lisp_Object*)value, true, file);
+            fputs("\n", file);
+        }
+    } break;
     case (Lisp_Object_Type::String): {
         if (print_repr) {
             putc('\"', file);