changeset 31396:307f68a41b03 v9.0.1031

patch 9.0.1031: Vim9 class is not implemented yet Commit: https://github.com/vim/vim/commit/00b28d6c23d8e662cab27e461825777c0a2e387a Author: Bram Moolenaar <Bram@vim.org> Date: Thu Dec 8 15:32:33 2022 +0000 patch 9.0.1031: Vim9 class is not implemented yet Problem: Vim9 class is not implemented yet. Solution: Add very basic class support.
author Bram Moolenaar <Bram@vim.org>
date Thu, 08 Dec 2022 16:45:03 +0100
parents 88027ff41075
children 3f10176bca14
files runtime/doc/vim9class.txt src/errors.h src/eval.c src/evalfunc.c src/evalvars.c src/if_py_both.h src/json.c src/proto/userfunc.pro src/proto/vim9class.pro src/proto/vim9instr.pro src/proto/vim9script.pro src/proto/vim9type.pro src/structs.h src/testdir/Make_all.mak src/testdir/test_vim9_class.vim src/testing.c src/typval.c src/userfunc.c src/version.c src/vim.h src/vim9.h src/vim9class.c src/vim9compile.c src/vim9execute.c src/vim9expr.c src/vim9instr.c src/vim9script.c src/vim9type.c src/viminfo.c
diffstat 29 files changed, 1067 insertions(+), 75 deletions(-) [+]
line wrap: on
line diff
--- a/runtime/doc/vim9class.txt
+++ b/runtime/doc/vim9class.txt
@@ -336,6 +336,9 @@ Defining a class ~
 A class is defined between `:class` and `:endclass`.  The whole class is
 defined in one script file.  It is not possible to add to a class later.
 
+A class can only be defined in a |Vim9| script file.  *E1315*
+A class cannot be defined inside a function.
+
 It is possible to define more than one class in a script file.  Although it
 usually is better to export only one main class.  It can be useful to define
 types, enums and helper classes though.
@@ -369,9 +372,9 @@ A class can extend one other class.
 							*implements*
 A class can implement one or more interfaces.
 							*specifies*
-A class can declare it's interface, the object members and methods, with a
+A class can declare its interface, the object members and methods, with a
 named interface.  This avoids the need for separately specifying the
-interface, which is often done an many languages, especially Java.
+interface, which is often done in many languages, especially Java.
 
 
 Defining an interface ~
@@ -634,7 +637,7 @@ directly writing you get an error, which
 to allow that.  This helps writing code with fewer mistakes.
 
 
-Making object membes private with an underscore ~
+Making object members private with an underscore ~
 
 When an object member is private, it can only be read and changed inside the
 class (and in sub-classes), then it cannot be used outside of the class.
--- a/src/errors.h
+++ b/src/errors.h
@@ -3346,4 +3346,28 @@ EXTERN char e_not_allowed_to_add_or_remo
 #ifdef FEAT_EVAL
 EXTERN char e_class_name_must_start_with_uppercase_letter_str[]
 	INIT(= N_("E1314: Class name must start with an uppercase letter: %s"));
-#endif
+EXTERN char e_white_space_required_after_class_name_str[]
+	INIT(= N_("E1315: White space required after class name: %s"));
+EXTERN char e_class_can_only_be_defined_in_vim9_script[]
+	INIT(= N_("E1316: Class can only be defined in Vim9 script"));
+EXTERN char e_invalid_object_member_declaration_str[]
+	INIT(= N_("E1317: Invalid object member declaration: %s"));
+EXTERN char e_not_valid_command_in_class_str[]
+	INIT(= N_("E1318: Not a valid command in a class: %s"));
+EXTERN char e_using_class_as_number[]
+	INIT(= N_("E1319: Using a class as a Number"));
+EXTERN char e_using_object_as_number[]
+	INIT(= N_("E1320: Using an object as a Number"));
+EXTERN char e_using_class_as_float[]
+	INIT(= N_("E1321: Using a class as a Float"));
+EXTERN char e_using_object_as_float[]
+	INIT(= N_("E1322: Using an object as a Float"));
+EXTERN char e_using_class_as_string[]
+	INIT(= N_("E1323: Using a class as a String"));
+EXTERN char e_using_object_as_string[]
+	INIT(= N_("E1324: Using an object as a String"));
+EXTERN char e_method_not_found_on_class_str_str[]
+	INIT(= N_("E1325: Method not found on class \"%s\": %s"));
+EXTERN char e_member_not_found_on_object_str_str[]
+	INIT(= N_("E1326: Member not found on object \"%s\": %s"));
+#endif
--- a/src/eval.c
+++ b/src/eval.c
@@ -1548,7 +1548,7 @@ set_var_lval(
     {
 	cc = *endp;
 	*endp = NUL;
-	if (in_vim9script() && check_reserved_name(lp->ll_name) == FAIL)
+	if (in_vim9script() && check_reserved_name(lp->ll_name, NULL) == FAIL)
 	    return;
 
 	if (lp->ll_blob != NULL)
@@ -1724,6 +1724,8 @@ tv_op(typval_T *tv1, typval_T *tv2, char
 	    case VAR_JOB:
 	    case VAR_CHANNEL:
 	    case VAR_INSTR:
+	    case VAR_CLASS:
+	    case VAR_OBJECT:
 		break;
 
 	    case VAR_BLOB:
@@ -3850,12 +3852,25 @@ handle_predefined(char_u *s, int len, ty
 		    return OK;
 		}
 		break;
+	case 10: if (STRNCMP(s, "null_class", 10) == 0)
+		{
+		    rettv->v_type = VAR_CLASS;
+		    rettv->vval.v_class = NULL;
+		    return OK;
+		}
+		 break;
 	case 11: if (STRNCMP(s, "null_string", 11) == 0)
 		{
 		    rettv->v_type = VAR_STRING;
 		    rettv->vval.v_string = NULL;
 		    return OK;
 		}
+		if (STRNCMP(s, "null_object", 11) == 0)
+		{
+		    rettv->v_type = VAR_OBJECT;
+		    rettv->vval.v_object = NULL;
+		    return OK;
+		}
 		break;
 	case 12:
 		if (STRNCMP(s, "null_channel", 12) == 0)
@@ -4685,6 +4700,8 @@ check_can_index(typval_T *rettv, int eva
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    if (verbose)
 		emsg(_(e_cannot_index_special_variable));
 	    return FAIL;
@@ -4788,6 +4805,8 @@ eval_index_inner(
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    break; // not evaluating, skipping over subscript
 
 	case VAR_NUMBER:
@@ -5781,6 +5800,16 @@ echo_string_core(
 	    r = (char_u *)"instructions";
 	    break;
 
+	case VAR_CLASS:
+	    *tofree = NULL;
+	    r = (char_u *)"class";
+	    break;
+
+	case VAR_OBJECT:
+	    *tofree = NULL;
+	    r = (char_u *)"object";
+	    break;
+
 	case VAR_FLOAT:
 	    *tofree = NULL;
 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
@@ -6588,6 +6617,20 @@ handle_subscript(
 		ret = FAIL;
 	    }
 	}
+	else if (**arg == '.' && (rettv->v_type == VAR_CLASS
+					       || rettv->v_type == VAR_OBJECT))
+	{
+	    // class member: SomeClass.varname
+	    // class method: SomeClass.SomeMethod()
+	    // class constructor: SomeClass.new()
+	    // object member: someObject.varname
+	    // object method: someObject.SomeMethod()
+	    if (class_object_index(arg, rettv, evalarg, verbose) == FAIL)
+	    {
+		clear_tv(rettv);
+		ret = FAIL;
+	    }
+	}
 	else
 	    break;
     }
@@ -6644,6 +6687,8 @@ item_copy(
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    copy_tv(from, to);
 	    break;
 	case VAR_LIST:
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -3770,6 +3770,12 @@ f_empty(typval_T *argvars, typval_T *ret
 	case VAR_SPECIAL:
 	    n = argvars[0].vval.v_number != VVAL_TRUE;
 	    break;
+	case VAR_CLASS:
+	    n = argvars[0].vval.v_class != NULL;
+	    break;
+	case VAR_OBJECT:
+	    n = argvars[0].vval.v_object != NULL;
+	    break;
 
 	case VAR_BLOB:
 	    n = argvars[0].vval.v_blob == NULL
@@ -7267,6 +7273,8 @@ f_len(typval_T *argvars, typval_T *rettv
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    emsg(_(e_invalid_type_for_len));
 	    break;
     }
@@ -10183,7 +10191,9 @@ f_substitute(typval_T *argvars, typval_T
 
     if (argvars[2].v_type == VAR_FUNC
 	    || argvars[2].v_type == VAR_PARTIAL
-	    || argvars[2].v_type == VAR_INSTR)
+	    || argvars[2].v_type == VAR_INSTR
+	    || argvars[2].v_type == VAR_CLASS
+	    || argvars[2].v_type == VAR_OBJECT)
 	expr = &argvars[2];
     else
 	sub = tv_get_string_buf_chk(&argvars[2], subbuf);
@@ -10617,6 +10627,8 @@ f_type(typval_T *argvars, typval_T *rett
 	case VAR_CHANNEL: n = VAR_TYPE_CHANNEL; break;
 	case VAR_BLOB:    n = VAR_TYPE_BLOB; break;
 	case VAR_INSTR:   n = VAR_TYPE_INSTR; break;
+	case VAR_CLASS:   n = VAR_TYPE_CLASS; break;
+	case VAR_OBJECT:  n = VAR_TYPE_OBJECT; break;
 	case VAR_UNKNOWN:
 	case VAR_ANY:
 	case VAR_VOID:
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -2264,6 +2264,8 @@ item_lock(typval_T *tv, int deep, int lo
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    break;
 
 	case VAR_BLOB:
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -6422,6 +6422,8 @@ ConvertToPyObject(typval_T *tv)
 	case VAR_CHANNEL:
 	case VAR_JOB:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    Py_INCREF(Py_None);
 	    return Py_None;
 	case VAR_BOOL:
--- a/src/json.c
+++ b/src/json.c
@@ -308,6 +308,8 @@ json_encode_item(garray_T *gap, typval_T
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    semsg(_(e_cannot_json_encode_str), vartype_name(val->v_type));
 	    return FAIL;
 
--- a/src/proto/userfunc.pro
+++ b/src/proto/userfunc.pro
@@ -7,6 +7,7 @@ char_u *register_cfunc(cfunc_T cb, cfunc
 int get_lambda_tv(char_u **arg, typval_T *rettv, int types_optional, evalarg_T *evalarg);
 char_u *deref_func_name(char_u *name, int *lenp, partial_T **partialp, type_T **type, int no_autoload, int new_function, int *found_var);
 void emsg_funcname(char *ermsg, char_u *name);
+int get_func_arguments(char_u **arg, evalarg_T *evalarg, int partial_argc, typval_T *argvars, int *argcount);
 int get_func_tv(char_u *name, int len, typval_T *rettv, char_u **arg, evalarg_T *evalarg, funcexe_T *funcexe);
 char_u *fname_trans_sid(char_u *name, char_u *fname_buf, char_u **tofree, int *error);
 void func_name_with_sid(char_u *name, int sid, char_u *buffer);
@@ -45,7 +46,7 @@ char_u *get_scriptlocal_funcname(char_u 
 char_u *alloc_printable_func_name(char_u *fname);
 char_u *save_function_name(char_u **name, int *is_global, int skip, int flags, funcdict_T *fudi);
 void list_functions(regmatch_T *regmatch);
-ufunc_T *define_function(exarg_T *eap, char_u *name_arg, garray_T *lines_to_free);
+ufunc_T *define_function(exarg_T *eap, char_u *name_arg, garray_T *lines_to_free, class_T *class_arg);
 void ex_function(exarg_T *eap);
 ufunc_T *find_func_by_name(char_u *name, compiletype_T *compile_type);
 void ex_defcompile(exarg_T *eap);
--- a/src/proto/vim9class.pro
+++ b/src/proto/vim9class.pro
@@ -1,6 +1,12 @@
 /* vim9class.c */
 void ex_class(exarg_T *eap);
+type_T *class_member_type(class_T *cl, char_u *name, char_u *name_end, int *member_idx);
 void ex_interface(exarg_T *eap);
 void ex_enum(exarg_T *eap);
 void ex_type(exarg_T *eap);
+int class_object_index(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int verbose);
+void copy_object(typval_T *from, typval_T *to);
+void object_unref(object_T *obj);
+void copy_class(typval_T *from, typval_T *to);
+void class_unref(typval_T *tv);
 /* vim: set ft=c : */
--- a/src/proto/vim9instr.pro
+++ b/src/proto/vim9instr.pro
@@ -3,6 +3,7 @@ isn_T *generate_instr(cctx_T *cctx, isnt
 isn_T *generate_instr_drop(cctx_T *cctx, isntype_T isn_type, int drop);
 isn_T *generate_instr_type(cctx_T *cctx, isntype_T isn_type, type_T *type);
 isn_T *generate_instr_debug(cctx_T *cctx);
+int generate_CONSTRUCT(cctx_T *cctx, class_T *cl);
 int may_generate_2STRING(int offset, int tolerant, cctx_T *cctx);
 int generate_add_instr(cctx_T *cctx, vartype_T vartype, type_T *type1, type_T *type2, exprtype_T expr_type);
 vartype_T operator_type(type_T *type1, type_T *type2);
--- a/src/proto/vim9script.pro
+++ b/src/proto/vim9script.pro
@@ -19,5 +19,5 @@ void update_vim9_script_var(int create, 
 void hide_script_var(scriptitem_T *si, int idx, int func_defined);
 svar_T *find_typval_in_script(typval_T *dest, scid_T sid, int must_find);
 int check_script_var_type(svar_T *sv, typval_T *value, char_u *name, where_T where);
-int check_reserved_name(char_u *name);
+int check_reserved_name(char_u *name, cctx_T *cctx);
 /* vim: set ft=c : */
--- a/src/proto/vim9type.pro
+++ b/src/proto/vim9type.pro
@@ -1,4 +1,5 @@
 /* vim9type.c */
+type_T *get_type_ptr(garray_T *type_gap);
 type_T *copy_type(type_T *type, garray_T *type_gap);
 void clear_type_list(garray_T *gap);
 type_T *alloc_type(type_T *type);
--- a/src/structs.h
+++ b/src/structs.h
@@ -1406,6 +1406,9 @@ typedef struct {
 typedef struct isn_S isn_T;	    // instruction
 typedef struct dfunc_S dfunc_T;	    // :def function
 
+typedef struct type_S type_T;
+typedef struct ufunc_S ufunc_T;
+
 typedef struct jobvar_S job_T;
 typedef struct readq_S readq_T;
 typedef struct writeq_S writeq_T;
@@ -1415,6 +1418,8 @@ typedef struct channel_S channel_T;
 typedef struct cctx_S cctx_T;
 typedef struct ectx_S ectx_T;
 typedef struct instr_S instr_T;
+typedef struct class_S class_T;
+typedef struct object_S object_T;
 
 typedef enum
 {
@@ -1434,16 +1439,18 @@ typedef enum
     VAR_JOB,		// "v_job" is used
     VAR_CHANNEL,	// "v_channel" is used
     VAR_INSTR,		// "v_instr" is used
+    VAR_CLASS,		// "v_class" is used
+    VAR_OBJECT,		// "v_object" is used
 } vartype_T;
 
 // A type specification.
-typedef struct type_S type_T;
 struct type_S {
     vartype_T	    tt_type;
     int8_T	    tt_argcount;    // for func, incl. vararg, -1 for unknown
     int8_T	    tt_min_argcount; // number of non-optional arguments
     char_u	    tt_flags;	    // TTFLAG_ values
     type_T	    *tt_member;	    // for list, dict, func return type
+				    // for class: class_T
     type_T	    **tt_args;	    // func argument types, allocated
 };
 
@@ -1452,6 +1459,38 @@ typedef struct {
     type_T	*type_decl;	    // declared type or equal to type_current
 } type2_T;
 
+/*
+ * Entry for an object member variable.
+ */
+typedef struct {
+    char_u	*om_name;  // allocated
+    type_T	*om_type;
+} objmember_T;
+
+// "class_T": used for v_class of typval of VAR_CLASS
+struct class_S
+{
+    char_u	*class_name;		// allocated
+    int		class_refcount;
+
+    int		class_obj_member_count;
+    objmember_T	*class_obj_members;	// allocated
+
+    int		class_obj_method_count;
+    ufunc_T	**class_obj_methods;	// allocated
+    ufunc_T	*class_new_func;	// new() function that was created
+
+    garray_T	class_type_list;	// used for type pointers
+    type_T	class_type;
+};
+
+// Used for v_object of typval of VAR_OBJECT.
+// The member variables follow in an array of typval_T.
+struct object_S {
+    class_T	*obj_class;  // class this object is created for
+    int		obj_refcount;
+};
+
 #define TTFLAG_VARARGS	0x01	    // func args ends with "..."
 #define TTFLAG_BOOL_OK	0x02	    // can be converted to bool
 #define TTFLAG_STATIC	0x04	    // one of the static types, e.g. t_any
@@ -1467,17 +1506,19 @@ typedef struct
     union
     {
 	varnumber_T	v_number;	// number value
-	float_T		v_float;	// floating number value
-	char_u		*v_string;	// string value (can be NULL!)
-	list_T		*v_list;	// list value (can be NULL!)
-	dict_T		*v_dict;	// dict value (can be NULL!)
+	float_T		v_float;	// floating point number value
+	char_u		*v_string;	// string value (can be NULL)
+	list_T		*v_list;	// list value (can be NULL)
+	dict_T		*v_dict;	// dict value (can be NULL)
 	partial_T	*v_partial;	// closure: function with args
 #ifdef FEAT_JOB_CHANNEL
-	job_T		*v_job;		// job value (can be NULL!)
-	channel_T	*v_channel;	// channel value (can be NULL!)
+	job_T		*v_job;		// job value (can be NULL)
+	channel_T	*v_channel;	// channel value (can be NULL)
 #endif
-	blob_T		*v_blob;	// blob value (can be NULL!)
+	blob_T		*v_blob;	// blob value (can be NULL)
 	instr_T		*v_instr;	// instructions to execute
+	class_T		*v_class;	// class value (can be NULL)
+	object_T	*v_object;	// object value (can be NULL)
     }		vval;
 } typval_T;
 
@@ -1663,7 +1704,7 @@ typedef enum {
  * Structure to hold info for a user function.
  * When adding a field check copy_lambda_to_global_func().
  */
-typedef struct
+struct ufunc_S
 {
     int		uf_varargs;	// variable nr of arguments (old style)
     int		uf_flags;	// FC_ flags
@@ -1671,6 +1712,9 @@ typedef struct
     int		uf_cleared;	// func_clear() was already called
     def_status_T uf_def_status; // UF_NOT_COMPILED, UF_TO_BE_COMPILED, etc.
     int		uf_dfunc_idx;	// only valid if uf_def_status is UF_COMPILED
+
+    class_T	*uf_class;	// for object method and constructor
+
     garray_T	uf_args;	// arguments, including optional arguments
     garray_T	uf_def_args;	// default argument expressions
     int		uf_args_visible; // normally uf_args.ga_len, less when
@@ -1731,7 +1775,7 @@ typedef struct
     char_u	uf_name[4];	// name of function (actual size equals name);
 				// can start with <SNR>123_ (<SNR> is K_SPECIAL
 				// KS_EXTRA KE_SNR)
-} ufunc_T;
+};
 
 // flags used in uf_flags
 #define FC_ABORT    0x01	// abort function on error
@@ -1750,6 +1794,9 @@ typedef struct
 				// copy_lambda_to_global_func()
 #define FC_LAMBDA   0x2000	// one line "return {expr}"
 
+#define FC_OBJECT   010000	// object method
+#define FC_NEW	    030000	// constructor (also an object method)
+
 #define MAX_FUNC_ARGS	20	// maximum number of function arguments
 #define VAR_SHORT_LEN	20	// short variable name length
 #define FIXVAR_CNT	12	// number of fixed variables
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -37,6 +37,7 @@ SCRIPTS_TINY_OUT = \
 TEST_VIM9 = \
 	test_vim9_assign \
 	test_vim9_builtin \
+	test_vim9_class \
 	test_vim9_cmd \
 	test_vim9_disassemble \
 	test_vim9_expr \
@@ -48,6 +49,7 @@ TEST_VIM9 = \
 TEST_VIM9_RES = \
 	test_vim9_assign.res \
 	test_vim9_builtin.res \
+	test_vim9_class.res \
 	test_vim9_cmd.res \
 	test_vim9_disassemble.res \
 	test_vim9_expr.res \
new file mode 100644
--- /dev/null
+++ b/src/testdir/test_vim9_class.vim
@@ -0,0 +1,145 @@
+" Test Vim9 classes
+
+source check.vim
+import './vim9.vim' as v9
+
+def Test_class_basic()
+  var lines =<< trim END
+      class NotWorking
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1316:')
+
+  lines =<< trim END
+      vim9script
+      class notWorking
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1314:')
+
+  lines =<< trim END
+      vim9script
+      class Not@working
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1315:')
+
+  lines =<< trim END
+      vim9script
+      abstract noclass Something
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E475:')
+
+  lines =<< trim END
+      vim9script
+      abstract classy Something
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E475:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+      endcl
+  END
+  v9.CheckScriptFailure(lines, 'E1065:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+      endclass school's out 
+  END
+  v9.CheckScriptFailure(lines, 'E488:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+      endclass | echo 'done'
+  END
+  v9.CheckScriptFailure(lines, 'E488:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1317:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this.
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1317:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this .count
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1317:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this. count
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1317:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this.count: number
+        that.count
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1318: Not a valid command in a class: that.count')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this.count
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1022:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this.count : number
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1059:')
+
+  lines =<< trim END
+      vim9script
+      class Something
+        this.count:number
+      endclass
+  END
+  v9.CheckScriptFailure(lines, 'E1069:')
+
+  lines =<< trim END
+      vim9script
+
+      class TextPosition
+        this.lnum: number
+	this.col: number
+      endclass
+
+      # # FIXME: this works but leaks memory
+      # # use the automatically generated new() method
+      # var pos = TextPosition.new(2, 12)
+      # assert_equal(2, pos.lnum)
+      # assert_equal(12, pos.col)
+  END
+  v9.CheckScriptSuccess(lines)
+enddef
+
+
+" vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker
--- a/src/testing.c
+++ b/src/testing.c
@@ -1101,6 +1101,8 @@ f_test_refcount(typval_T *argvars, typva
 	case VAR_SPECIAL:
 	case VAR_STRING:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    break;
 	case VAR_JOB:
 #ifdef FEAT_JOB_CHANNEL
--- a/src/typval.c
+++ b/src/typval.c
@@ -84,6 +84,13 @@ free_tv(typval_T *varp)
 		channel_unref(varp->vval.v_channel);
 		break;
 #endif
+	    case VAR_CLASS:
+		class_unref(varp);
+		break;
+	    case VAR_OBJECT:
+		object_unref(varp->vval.v_object);
+		break;
+
 	    case VAR_NUMBER:
 	    case VAR_FLOAT:
 	    case VAR_ANY:
@@ -153,6 +160,12 @@ clear_tv(typval_T *varp)
 	    case VAR_INSTR:
 		VIM_CLEAR(varp->vval.v_instr);
 		break;
+	    case VAR_CLASS:
+		class_unref(varp);
+		break;
+	    case VAR_OBJECT:
+		object_unref(varp->vval.v_object);
+		break;
 	    case VAR_UNKNOWN:
 	    case VAR_ANY:
 	    case VAR_VOID:
@@ -234,6 +247,12 @@ tv_get_bool_or_number_chk(typval_T *varp
 	case VAR_BLOB:
 	    emsg(_(e_using_blob_as_number));
 	    break;
+	case VAR_CLASS:
+	    emsg(_(e_using_class_as_number));
+	    break;
+	case VAR_OBJECT:
+	    emsg(_(e_using_object_as_number));
+	    break;
 	case VAR_VOID:
 	    emsg(_(e_cannot_use_void_value));
 	    break;
@@ -333,6 +352,12 @@ tv_get_float_chk(typval_T *varp, int *er
 	case VAR_BLOB:
 	    emsg(_(e_using_blob_as_float));
 	    break;
+	case VAR_CLASS:
+	    emsg(_(e_using_class_as_float));
+	    break;
+	case VAR_OBJECT:
+	    emsg(_(e_using_object_as_float));
+	    break;
 	case VAR_VOID:
 	    emsg(_(e_cannot_use_void_value));
 	    break;
@@ -1029,6 +1054,12 @@ tv_get_string_buf_chk_strict(typval_T *v
 	case VAR_BLOB:
 	    emsg(_(e_using_blob_as_string));
 	    break;
+	case VAR_CLASS:
+	    emsg(_(e_using_class_as_string));
+	    break;
+	case VAR_OBJECT:
+	    emsg(_(e_using_object_as_string));
+	    break;
 	case VAR_JOB:
 #ifdef FEAT_JOB_CHANNEL
 	    if (in_vim9script())
@@ -1158,6 +1189,14 @@ copy_tv(typval_T *from, typval_T *to)
 	    to->vval.v_instr = from->vval.v_instr;
 	    break;
 
+	case VAR_CLASS:
+	    copy_class(from, to);
+	    break;
+
+	case VAR_OBJECT:
+	    copy_object(from, to);
+	    break;
+
 	case VAR_STRING:
 	case VAR_FUNC:
 	    if (from->vval.v_string == NULL)
@@ -1878,6 +1917,13 @@ tv_equal(
 	case VAR_INSTR:
 	    return tv1->vval.v_instr == tv2->vval.v_instr;
 
+	case VAR_CLASS:
+	    return tv1->vval.v_class == tv2->vval.v_class;
+
+	case VAR_OBJECT:
+	    // TODO: compare values
+	    return tv1->vval.v_object == tv2->vval.v_object;
+
 	case VAR_PARTIAL:
 	    return tv1->vval.v_partial == tv2->vval.v_partial;
 
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -214,6 +214,8 @@ get_function_args(
     garray_T	*default_args,
     int		skip,
     exarg_T	*eap,		// can be NULL
+    class_T	*class_arg,
+    garray_T	*newlines,	// function body lines
     garray_T	*lines_to_free)
 {
     int		mustend = FALSE;
@@ -292,6 +294,51 @@ get_function_args(
 		}
 	    }
 	}
+	else if (class_arg != NULL && STRNCMP(p, "this.", 5) == 0)
+	{
+	    // this.memberName
+	    p += 5;
+	    arg = p;
+	    while (ASCII_ISALNUM(*p) || *p == '_')
+		++p;
+
+	    // TODO: check the argument is indeed a member
+	    if (newargs != NULL && ga_grow(newargs, 1) == FAIL)
+		return FAIL;
+	    if (newargs != NULL)
+	    {
+		((char_u **)(newargs->ga_data))[newargs->ga_len] =
+						    vim_strnsave(arg, p - arg);
+		newargs->ga_len++;
+
+		if (argtypes != NULL && ga_grow(argtypes, 1) == OK)
+		{
+		    // TODO: use the actual type
+		    ((char_u **)argtypes->ga_data)[argtypes->ga_len++] =
+						  vim_strsave((char_u *)"any");
+
+		    // Add a line to the function body for the assignment.
+		    if (ga_grow(newlines, 1) == OK)
+		    {
+			// "this.name = name"
+			int len = 5 + (p - arg) + 3 + (p - arg) + 1;
+			char_u *assignment = alloc(len);
+			if (assignment != NULL)
+			{
+			    c = *p;
+			    *p = NUL;
+			    vim_snprintf((char *)assignment, len,
+						     "this.%s = %s", arg, arg);
+			    *p = c;
+			    ((char_u **)(newlines->ga_data))[
+					      newlines->ga_len++] = assignment;
+			}
+		    }
+		}
+	    }
+	    if (*p == ',')
+		++p;
+	}
 	else
 	{
 	    char_u *np;
@@ -1389,7 +1436,7 @@ get_lambda_tv(
     s = *arg + 1;
     ret = get_function_args(&s, equal_arrow ? ')' : '-', NULL,
 	    types_optional ? &argtypes : NULL, types_optional, evalarg,
-					NULL, &default_args, TRUE, NULL, NULL);
+			    NULL, &default_args, TRUE, NULL, NULL, NULL, NULL);
     if (ret == FAIL || skip_arrow(s, equal_arrow, &ret_type, NULL) == NULL)
     {
 	if (types_optional)
@@ -1406,7 +1453,7 @@ get_lambda_tv(
     ret = get_function_args(arg, equal_arrow ? ')' : '-', pnewargs,
 	    types_optional ? &argtypes : NULL, types_optional, evalarg,
 					    &varargs, &default_args,
-					    FALSE, NULL, NULL);
+					    FALSE, NULL, NULL, NULL, NULL);
     if (ret == FAIL
 		  || (s = skip_arrow(*arg, equal_arrow, &ret_type,
 		equal_arrow || vim9script ? &white_error : NULL)) == NULL)
@@ -1733,7 +1780,7 @@ emsg_funcname(char *ermsg, char_u *name)
  * Return them in "*argvars[MAX_FUNC_ARGS + 1]" and the count in "argcount".
  * On failure FAIL is returned but the "argvars[argcount]" are still set.
  */
-    static int
+    int
 get_func_arguments(
 	char_u	    **arg,
 	evalarg_T   *evalarg,
@@ -1809,7 +1856,7 @@ get_func_tv(
     funcexe_T	*funcexe)	// various values
 {
     char_u	*argp;
-    int		ret = OK;
+    int		ret;
     typval_T	argvars[MAX_FUNC_ARGS + 1];	// vars for arguments
     int		argcount = 0;			// number of arguments found
     int		vim9script = in_vim9script();
@@ -4370,10 +4417,15 @@ list_functions(regmatch_T *regmatch)
  * When "name_arg" is not NULL this is a nested function, using "name_arg" for
  * the function name.
  * "lines_to_free" is a list of strings to be freed later.
+ * If "class_arg" is not NULL then the function is defined in this class.
  * Returns a pointer to the function or NULL if no function defined.
  */
     ufunc_T *
-define_function(exarg_T *eap, char_u *name_arg, garray_T *lines_to_free)
+define_function(
+	exarg_T	    *eap,
+	char_u	    *name_arg,
+	garray_T    *lines_to_free,
+	class_T	    *class_arg)
 {
     int		j;
     int		c;
@@ -4488,8 +4540,9 @@ define_function(exarg_T *eap, char_u *na
 	    p = eap->arg;
 	}
 
-	name = save_function_name(&p, &is_global, eap->skip,
-					TFN_NO_AUTOLOAD | TFN_NEW_FUNC, &fudi);
+	int tfn_flags = TFN_NO_AUTOLOAD | TFN_NEW_FUNC
+					      | (class_arg == 0 ? 0 : TFN_INT);
+	name = save_function_name(&p, &is_global, eap->skip, tfn_flags, &fudi);
 	paren = (vim_strchr(p, '(') != NULL);
 	if (name == NULL && (fudi.fd_dict == NULL || !paren) && !eap->skip)
 	{
@@ -4690,7 +4743,7 @@ define_function(exarg_T *eap, char_u *na
     if (get_function_args(&p, ')', &newargs,
 			eap->cmdidx == CMD_def ? &argtypes : NULL, FALSE,
 			 NULL, &varargs, &default_args, eap->skip,
-			 eap, lines_to_free) == FAIL)
+			 eap, class_arg, &newlines, lines_to_free) == FAIL)
 	goto errret_2;
     whitep = p;
 
@@ -5145,7 +5198,7 @@ ex_function(exarg_T *eap)
     garray_T lines_to_free;
 
     ga_init2(&lines_to_free, sizeof(char_u *), 50);
-    (void)define_function(eap, NULL, &lines_to_free);
+    (void)define_function(eap, NULL, &lines_to_free, NULL);
     ga_clear_strings(&lines_to_free);
 }
 
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1031,
+/**/
     1030,
 /**/
     1029,
--- a/src/vim.h
+++ b/src/vim.h
@@ -2120,6 +2120,8 @@ typedef int sock_T;
 #define VAR_TYPE_CHANNEL    9
 #define VAR_TYPE_BLOB	    10
 #define VAR_TYPE_INSTR	    11
+#define VAR_TYPE_CLASS	    12
+#define VAR_TYPE_OBJECT	    13
 
 #define DICT_MAXNEST 100	// maximum nesting of lists and dicts
 
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -32,6 +32,7 @@ typedef enum {
 
     ISN_SOURCE,	    // source autoload script, isn_arg.number is the script ID
     ISN_INSTR,	    // instructions compiled from expression
+    ISN_CONSTRUCT,  // construct an object, using contstruct_T
 
     // get and set variables
     ISN_LOAD,	    // push local variable isn_arg.number
@@ -110,6 +111,7 @@ typedef enum {
     ISN_PCALL_END,  // cleanup after ISN_PCALL with cpf_top set
     ISN_RETURN,	    // return, result is on top of stack
     ISN_RETURN_VOID, // Push void, then return
+    ISN_RETURN_OBJECT, // Push constructed object, then return
     ISN_FUNCREF,    // push a function ref to dfunc isn_arg.funcref
     ISN_NEWFUNC,    // create a global function from a lambda function
     ISN_DEF,	    // list functions
@@ -463,6 +465,12 @@ typedef struct {
     long	ewin_time;	    // time argument (msec)
 } echowin_T;
 
+// arguments to ISN_CONSTRUCT
+typedef struct {
+    int		construct_size;	    // size of object in bytes
+    class_T	*construct_class;   // class the object is created from
+} construct_T;
+
 /*
  * Instruction
  */
@@ -514,6 +522,7 @@ struct isn_S {
 	debug_T		    debug;
 	deferins_T	    defer;
 	echowin_T	    echowin;
+	construct_T	    construct;
     } isn_arg;
 };
 
@@ -757,7 +766,8 @@ typedef struct {
 
     int		    lhs_has_type;   // type was specified
     type_T	    *lhs_type;
-    type_T	    *lhs_member_type;
+    int		    lhs_member_idx;    // object member index
+    type_T	    *lhs_member_type;  // list/dict/object member type
 
     int		    lhs_append;	    // used by ISN_REDIREND
 } lhs_T;
--- a/src/vim9class.c
+++ b/src/vim9class.c
@@ -27,9 +27,16 @@
     void
 ex_class(exarg_T *eap)
 {
-    int is_abstract = eap->cmdidx == CMD_abstract;
+    if (!current_script_is_vim9()
+		|| (cmdmod.cmod_flags & CMOD_LEGACY)
+		|| !getline_equal(eap->getline, eap->cookie, getsourceline))
+    {
+	emsg(_(e_class_can_only_be_defined_in_vim9_script));
+	return;
+    }
 
     char_u *arg = eap->arg;
+    int is_abstract = eap->cmdidx == CMD_abstract;
     if (is_abstract)
     {
 	if (STRNCMP(arg, "class", 5) != 0 || !VIM_ISWHITE(arg[5]))
@@ -45,38 +52,286 @@ ex_class(exarg_T *eap)
 	semsg(_(e_class_name_must_start_with_uppercase_letter_str), arg);
 	return;
     }
+    char_u *name_end = find_name_end(arg, NULL, NULL, FNE_CHECK_START);
+    if (!IS_WHITE_OR_NUL(*name_end))
+    {
+	semsg(_(e_white_space_required_after_class_name_str), arg);
+	return;
+    }
 
     // TODO:
-    // generics: <Tkey, Tentry>
+    //    generics: <Tkey, Tentry>
     //    extends SomeClass
     //    implements SomeInterface
     //    specifies SomeInterface
+    //    check nothing follows
 
+    // TODO: handle "is_export" if it is set
+
+    garray_T	type_list;	    // list of pointers to allocated types
+    ga_init2(&type_list, sizeof(type_T *), 10);
+
+    // Growarray with object members declared in the class.
+    garray_T objmembers;
+    ga_init2(&objmembers, sizeof(objmember_T), 10);
+
+    // Growarray with object methods declared in the class.
+    garray_T objmethods;
+    ga_init2(&objmethods, sizeof(ufunc_T), 10);
+
+    /*
+     * Go over the body of the class until "endclass" is found.
+     */
+    char_u *theline = NULL;
+    int success = FALSE;
+    for (;;)
+    {
+	vim_free(theline);
+	theline = eap->getline(':', eap->cookie, 0, GETLINE_CONCAT_ALL);
+	if (theline == NULL)
+	    break;
+	char_u *line = skipwhite(theline);
+
+	// TODO:
+	// class members (public, read access, private):
+	//	  static varname
+	//	  public static varname
+	//	  static _varname
+	//
+	// constructors:
+	//	  def new()
+	//	  enddef
+	//	  def newOther()
+	//	  enddef
+	//
+	// methods (object, class, generics):
+	//	  def someMethod()
+	//	  enddef
+	//	  static def someMethod()
+	//	  enddef
+	//	  def <Tval> someMethod()
+	//	  enddef
+	//	  static def <Tval> someMethod()
+	//	  enddef
+
+	char_u *p = line;
+	if (checkforcmd(&p, "endclass", 4))
+	{
+	    if (STRNCMP(line, "endclass", 8) != 0)
+		semsg(_(e_command_cannot_be_shortened_str), line);
+	    else if (*p == '|' || !ends_excmd2(line, p))
+		semsg(_(e_trailing_characters_str), p);
+
+	    success = TRUE;
+	    break;
+	}
+
+	// "this.varname"
+	// "this._varname"
+	// TODO:
+	//	"public this.varname"
+	if (STRNCMP(line, "this", 4) == 0)
+	{
+	    if (line[4] != '.' || !eval_isnamec1(line[5]))
+	    {
+		semsg(_(e_invalid_object_member_declaration_str), line);
+		break;
+	    }
+	    char_u *varname = line + 5;
+	    char_u *varname_end = to_name_end(varname, FALSE);
+
+	    char_u *colon = skipwhite(varname_end);
+	    // TODO: accept initialization and figure out type from it
+	    if (*colon != ':')
+	    {
+		emsg(_(e_type_or_initialization_required));
+		break;
+	    }
+	    if (VIM_ISWHITE(*varname_end))
+	    {
+		semsg(_(e_no_white_space_allowed_before_colon_str), varname);
+		break;
+	    }
+	    if (!VIM_ISWHITE(colon[1]))
+	    {
+		semsg(_(e_white_space_required_after_str_str), ":", varname);
+		break;
+	    }
+
+	    char_u *type_arg = skipwhite(colon + 1);
+	    type_T *type = parse_type(&type_arg, &type_list, TRUE);
+	    if (type == NULL)
+		break;
+
+	    if (ga_grow(&objmembers, 1) == FAIL)
+		break;
+	    objmember_T *m = ((objmember_T *)objmembers.ga_data)
+							  + objmembers.ga_len;
+	    m->om_name = vim_strnsave(varname, varname_end - varname);
+	    m->om_type = type;
+	    ++objmembers.ga_len;
+	}
+
+	else
+	{
+	    semsg(_(e_not_valid_command_in_class_str), line);
+	    break;
+	}
+    }
+    vim_free(theline);
+
+    if (success)
+    {
+	class_T *cl = ALLOC_CLEAR_ONE(class_T);
+	if (cl == NULL)
+	    goto cleanup;
+	cl->class_refcount = 1;
+	cl->class_name = vim_strnsave(arg, name_end - arg);
 
-    // TODO: handle until "endclass" is found:
-    // object and class members (public, read access, private):
-    //	  public this.varname
-    //	  public static varname
-    //	  this.varname
-    //	  static varname
-    //	  this._varname
-    //	  static _varname
-    //
-    // constructors:
-    //	  def new()
-    //	  enddef
-    //	  def newOther()
-    //	  enddef
-    //
-    // methods (object, class, generics):
-    //	  def someMethod()
-    //	  enddef
-    //	  static def someMethod()
-    //	  enddef
-    //	  def <Tval> someMethod()
-    //	  enddef
-    //	  static def <Tval> someMethod()
-    //	  enddef
+	// Members are used by the new() function, add them here.
+	cl->class_obj_member_count = objmembers.ga_len;
+	cl->class_obj_members = ALLOC_MULT(objmember_T, objmembers.ga_len);
+	if (cl->class_name == NULL
+		|| cl->class_obj_members == NULL)
+	{
+	    vim_free(cl->class_name);
+	    vim_free(cl->class_obj_members);
+	    vim_free(cl);
+	    goto cleanup;
+	}
+	mch_memmove(cl->class_obj_members, objmembers.ga_data,
+				      sizeof(objmember_T) * objmembers.ga_len);
+	vim_free(objmembers.ga_data);
+
+	int have_new = FALSE;
+	for (int i = 0; i < objmethods.ga_len; ++i)
+	    if (STRCMP((((ufunc_T *)objmethods.ga_data) + i)->uf_name,
+								   "new") == 0)
+	    {
+		have_new = TRUE;
+		break;
+	    }
+	if (!have_new)
+	{
+	    // No new() method was defined, add the default constructor.
+	    garray_T fga;
+	    ga_init2(&fga, 1, 1000);
+	    ga_concat(&fga, (char_u *)"new(");
+	    for (int i = 0; i < cl->class_obj_member_count; ++i)
+	    {
+		if (i > 0)
+		    ga_concat(&fga, (char_u *)", ");
+		ga_concat(&fga, (char_u *)"this.");
+		objmember_T *m = cl->class_obj_members + i;
+		ga_concat(&fga, (char_u *)m->om_name);
+	    }
+	    ga_concat(&fga, (char_u *)")\nenddef\n");
+	    ga_append(&fga, NUL);
+
+	    exarg_T fea;
+	    CLEAR_FIELD(fea);
+	    fea.cmdidx = CMD_def;
+	    fea.cmd = fea.arg = fga.ga_data;
+
+	    garray_T lines_to_free;
+	    ga_init2(&lines_to_free, sizeof(char_u *), 50);
+
+	    ufunc_T *nf = define_function(&fea, NULL, &lines_to_free, cl);
+
+	    ga_clear_strings(&lines_to_free);
+	    vim_free(fga.ga_data);
+
+	    if (nf != NULL && ga_grow(&objmethods, 1) == OK)
+	    {
+		((ufunc_T **)objmethods.ga_data)[objmethods.ga_len] = nf;
+		++objmethods.ga_len;
+
+		nf->uf_flags |= FC_NEW;
+		nf->uf_class = cl;
+		nf->uf_ret_type = get_type_ptr(&type_list);
+		if (nf->uf_ret_type != NULL)
+		{
+		    nf->uf_ret_type->tt_type = VAR_OBJECT;
+		    nf->uf_ret_type->tt_member = (type_T *)cl;
+		    nf->uf_ret_type->tt_argcount = 0;
+		    nf->uf_ret_type->tt_args = NULL;
+		}
+		cl->class_new_func = nf;
+	    }
+	}
+
+	cl->class_obj_method_count = objmethods.ga_len;
+	cl->class_obj_methods = ALLOC_MULT(ufunc_T *, objmethods.ga_len);
+	if (cl->class_obj_methods == NULL)
+	{
+	    vim_free(cl->class_name);
+	    vim_free(cl->class_obj_members);
+	    vim_free(cl->class_obj_methods);
+	    vim_free(cl);
+	    goto cleanup;
+	}
+	mch_memmove(cl->class_obj_methods, objmethods.ga_data,
+					sizeof(ufunc_T *) * objmethods.ga_len);
+	vim_free(objmethods.ga_data);
+
+	cl->class_type.tt_type = VAR_CLASS;
+	cl->class_type.tt_member = (type_T *)cl;
+	cl->class_type_list = type_list;
+
+	// TODO:
+	// - Add the methods to the class
+	//	- array with ufunc_T pointers
+	// - Fill hashtab with object members and methods
+	// - Generate the default new() method, if needed.
+	// Later:
+	// - class members
+	// - class methods
+
+	// Add the class to the script-local variables.
+	typval_T tv;
+	tv.v_type = VAR_CLASS;
+	tv.vval.v_class = cl;
+	set_var_const(cl->class_name, current_sctx.sc_sid,
+					     NULL, &tv, FALSE, ASSIGN_DECL, 0);
+	return;
+    }
+
+cleanup:
+    for (int i = 0; i < objmembers.ga_len; ++i)
+    {
+	objmember_T *m = ((objmember_T *)objmembers.ga_data) + i;
+	vim_free(m->om_name);
+    }
+    ga_clear(&objmembers);
+
+    ga_clear(&objmethods);
+    clear_type_list(&type_list);
+}
+
+/*
+ * Find member "name" in class "cl" and return its type.
+ * When not found t_any is returned.
+ */
+    type_T *
+class_member_type(
+	class_T *cl,
+	char_u	*name,
+	char_u	*name_end,
+	int	*member_idx)
+{
+    *member_idx = -1;  // not found (yet)
+    size_t len = name_end - name;
+
+    for (int i = 0; i < cl->class_obj_member_count; ++i)
+    {
+	objmember_T *m = cl->class_obj_members + i;
+	if (STRNCMP(m->om_name, name, len) == 0 && m->om_name[len] == NUL)
+	{
+	    *member_idx = i;
+	    return m->om_type;
+	}
+    }
+    return &t_any;
 }
 
 /*
@@ -106,5 +361,191 @@ ex_type(exarg_T *eap UNUSED)
     // TODO
 }
 
+/*
+ * Evaluate what comes after a class:
+ * - class member: SomeClass.varname
+ * - class method: SomeClass.SomeMethod()
+ * - class constructor: SomeClass.new()
+ * - object member: someObject.varname
+ * - object method: someObject.SomeMethod()
+ *
+ * "*arg" points to the '.'.
+ * "*arg" is advanced to after the member name or method call.
+ *
+ * Returns FAIL or OK.
+ */
+    int
+class_object_index(
+    char_u	**arg,
+    typval_T	*rettv,
+    evalarg_T	*evalarg,
+    int		verbose UNUSED)	// give error messages
+{
+    // int		evaluate = evalarg != NULL
+    //				      && (evalarg->eval_flags & EVAL_EVALUATE);
+
+    if (VIM_ISWHITE((*arg)[1]))
+    {
+	semsg(_(e_no_white_space_allowed_after_str_str), ".", *arg);
+	return FAIL;
+    }
+
+    ++*arg;
+    char_u *name = *arg;
+    char_u *name_end = find_name_end(name, NULL, NULL, FNE_CHECK_START);
+    if (name_end == name)
+	return FAIL;
+    size_t len = name_end - name;
+
+    class_T *cl = rettv->v_type == VAR_CLASS ? rettv->vval.v_class
+					     : rettv->vval.v_object->obj_class;
+    if (*name_end == '(')
+    {
+	for (int i = 0; i < cl->class_obj_method_count; ++i)
+	{
+	    ufunc_T *fp = cl->class_obj_methods[i];
+	    if (STRNCMP(name, fp->uf_name, len) == 0 && fp->uf_name[len] == NUL)
+	    {
+		typval_T    argvars[MAX_FUNC_ARGS + 1];
+		int	    argcount = 0;
+
+		char_u *argp = name_end;
+		int ret = get_func_arguments(&argp, evalarg, 0,
+							   argvars, &argcount);
+		if (ret == FAIL)
+		    return FAIL;
+
+		funcexe_T   funcexe;
+		CLEAR_FIELD(funcexe);
+		funcexe.fe_evaluate = TRUE;
+
+		// Call the user function.  Result goes into rettv;
+		// TODO: pass the object
+		rettv->v_type = VAR_UNKNOWN;
+		int error = call_user_func_check(fp, argcount, argvars,
+							rettv, &funcexe, NULL);
+
+		// Clear the arguments.
+		for (int idx = 0; idx < argcount; ++idx)
+		    clear_tv(&argvars[idx]);
+
+		if (error != FCERR_NONE)
+		{
+		    user_func_error(error, printable_func_name(fp),
+							 funcexe.fe_found_var);
+		    return FAIL;
+		}
+		*arg = argp;
+		return OK;
+	    }
+	}
+
+	semsg(_(e_method_not_found_on_class_str_str), cl->class_name, name);
+    }
+
+    else if (rettv->v_type == VAR_OBJECT)
+    {
+	for (int i = 0; i < cl->class_obj_member_count; ++i)
+	{
+	    objmember_T *m = &cl->class_obj_members[i];
+	    if (STRNCMP(name, m->om_name, len) == 0 && m->om_name[len] == NUL)
+	    {
+		// The object only contains a pointer to the class, the member
+		// values array follows right after that.
+		object_T *obj = rettv->vval.v_object;
+		typval_T *tv = (typval_T *)(obj + 1) + i;
+		copy_tv(tv, rettv);
+		object_unref(obj);
+
+		*arg = name_end;
+		return OK;
+	    }
+	}
+
+	semsg(_(e_member_not_found_on_object_str_str), cl->class_name, name);
+    }
+
+    // TODO: class member
+
+    return FAIL;
+}
+
+/*
+ * Make a copy of an object.
+ */
+    void
+copy_object(typval_T *from, typval_T *to)
+{
+    *to = *from;
+    if (to->vval.v_object != NULL)
+	++to->vval.v_object->obj_refcount;
+}
+
+/*
+ * Free an object.
+ */
+    static void
+object_clear(object_T *obj)
+{
+    class_T *cl = obj->obj_class;
+
+    // the member values are just after the object structure
+    typval_T *tv = (typval_T *)(obj + 1);
+    for (int i = 0; i < cl->class_obj_member_count; ++i)
+	clear_tv(tv + i);
+
+    vim_free(obj);
+}
+
+/*
+ * Unreference an object.
+ */
+    void
+object_unref(object_T *obj)
+{
+    if (obj != NULL && --obj->obj_refcount <= 0)
+	object_clear(obj);
+}
+
+/*
+ * Make a copy of a class.
+ */
+    void
+copy_class(typval_T *from, typval_T *to)
+{
+    *to = *from;
+    if (to->vval.v_class != NULL)
+	++to->vval.v_class->class_refcount;
+}
+
+/*
+ * Unreference a class.  Free it when the reference count goes down to zero.
+ */
+    void
+class_unref(typval_T *tv)
+{
+    class_T *cl = tv->vval.v_class;
+    if (cl != NULL && --cl->class_refcount <= 0)
+    {
+	vim_free(cl->class_name);
+
+	for (int i = 0; i < cl->class_obj_member_count; ++i)
+	{
+	    objmember_T *m = &cl->class_obj_members[i];
+	    vim_free(m->om_name);
+	}
+	vim_free(cl->class_obj_members);
+
+	vim_free(cl->class_obj_methods);
+
+	if (cl->class_new_func != NULL)
+	    func_ptr_unref(cl->class_new_func);
+
+	clear_type_list(&cl->class_type_list);
+
+	vim_free(cl);
+    }
+}
+
 
 #endif // FEAT_EVAL
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -43,6 +43,20 @@ lookup_local(char_u *name, size_t len, l
     if (len == 0)
 	return FAIL;
 
+    if (len == 4 && STRNCMP(name, "this", 4) == 0
+	    && cctx->ctx_ufunc != NULL
+	    && (cctx->ctx_ufunc->uf_flags & FC_OBJECT))
+    {
+	if (lvar != NULL)
+	{
+	    CLEAR_POINTER(lvar);
+	    lvar->lv_name = (char_u *)"this";
+	    if (cctx->ctx_ufunc->uf_class != NULL)
+		lvar->lv_type = &cctx->ctx_ufunc->uf_class->class_type;
+	}
+	return OK;
+    }
+
     // Find local in current function scope.
     for (idx = 0; idx < cctx->ctx_locals.ga_len; ++idx)
     {
@@ -296,7 +310,11 @@ variable_exists(char_u *name, size_t len
 {
     return (cctx != NULL
 		&& (lookup_local(name, len, NULL, cctx) == OK
-		    || arg_exists(name, len, NULL, NULL, NULL, cctx) == OK))
+		    || arg_exists(name, len, NULL, NULL, NULL, cctx) == OK
+		    || (len == 4
+			&& cctx->ctx_ufunc != NULL
+			&& (cctx->ctx_ufunc->uf_flags & FC_OBJECT)
+			&& STRNCMP(name, "this", 4) == 0)))
 	    || script_var_exists(name, len, cctx, NULL) == OK
 	    || find_imported(name, len, FALSE) != NULL;
 }
@@ -957,7 +975,7 @@ compile_nested_function(exarg_T *eap, cc
 	goto theend;
     }
 
-    ufunc = define_function(eap, lambda_name, lines_to_free);
+    ufunc = define_function(eap, lambda_name, lines_to_free, NULL);
     if (ufunc == NULL)
     {
 	r = eap->skip ? OK : FAIL;
@@ -1450,6 +1468,7 @@ compile_lhs(
     lhs->lhs_dest = dest_local;
     lhs->lhs_vimvaridx = -1;
     lhs->lhs_scriptvar_idx = -1;
+    lhs->lhs_member_idx = -1;
 
     // "dest_end" is the end of the destination, including "[expr]" or
     // ".name".
@@ -1509,7 +1528,7 @@ compile_lhs(
 	else
 	{
 	    // No specific kind of variable recognized, just a name.
-	    if (check_reserved_name(lhs->lhs_name) == FAIL)
+	    if (check_reserved_name(lhs->lhs_name, cctx) == FAIL)
 		return FAIL;
 
 	    if (lookup_local(var_start, lhs->lhs_varlen,
@@ -1757,8 +1776,16 @@ compile_lhs(
 	    lhs->lhs_type = &t_any;
 	}
 
-	if (lhs->lhs_type->tt_member == NULL)
+	if (lhs->lhs_type == NULL || lhs->lhs_type->tt_member == NULL)
 	    lhs->lhs_member_type = &t_any;
+	else if (lhs->lhs_type->tt_type == VAR_CLASS
+		|| lhs->lhs_type->tt_type == VAR_OBJECT)
+	{
+	    // for an object or class member get the type of the member
+	    class_T *cl = (class_T *)lhs->lhs_type->tt_member;
+	    lhs->lhs_member_type = class_member_type(cl, after + 1,
+					   lhs->lhs_end, &lhs->lhs_member_idx);
+	}
 	else
 	    lhs->lhs_member_type = lhs->lhs_type->tt_member;
     }
@@ -1880,6 +1907,11 @@ compile_assign_index(
 	    r = FAIL;
 	}
     }
+    else if (lhs->lhs_member_idx >= 0)
+    {
+	// object member index
+	r = generate_PUSHNR(cctx, lhs->lhs_member_idx);
+    }
     else // if (*p == '.')
     {
 	char_u *key_end = to_name_end(p + 1, TRUE);
@@ -1996,7 +2028,7 @@ compile_assign_unlet(
 	return FAIL;
     }
 
-    if (lhs->lhs_type == &t_any)
+    if (lhs->lhs_type == NULL || lhs->lhs_type == &t_any)
     {
 	// Index on variable of unknown type: check at runtime.
 	dest_type = VAR_ANY;
@@ -2042,8 +2074,12 @@ compile_assign_unlet(
     if (compile_load_lhs(lhs, var_start, rhs_type, cctx) == FAIL)
 	return FAIL;
 
-    if (dest_type == VAR_LIST || dest_type == VAR_DICT
-			      || dest_type == VAR_BLOB || dest_type == VAR_ANY)
+    if (dest_type == VAR_LIST
+	    || dest_type == VAR_DICT
+	    || dest_type == VAR_BLOB
+	    || dest_type == VAR_CLASS
+	    || dest_type == VAR_OBJECT
+	    || dest_type == VAR_ANY)
     {
 	if (is_assign)
 	{
@@ -2466,6 +2502,8 @@ compile_assignment(char_u *arg, exarg_T 
 		    case VAR_PARTIAL:
 		    case VAR_VOID:
 		    case VAR_INSTR:
+		    case VAR_CLASS:
+		    case VAR_OBJECT:
 		    case VAR_SPECIAL:  // cannot happen
 			// This is skipped for local variables, they are always
 			// initialized to zero.  But in a "for" or "while" loop
@@ -2897,6 +2935,22 @@ compile_def_function(
     if (check_args_shadowing(ufunc, &cctx) == FAIL)
 	goto erret;
 
+    // For an object method and constructor "this" is the first local variable.
+    if (ufunc->uf_flags & FC_OBJECT)
+    {
+	dfunc_T *dfunc = ((dfunc_T *)def_functions.ga_data)
+							 + ufunc->uf_dfunc_idx;
+	if (GA_GROW_FAILS(&dfunc->df_var_names, 1))
+	    goto erret;
+	((char_u **)dfunc->df_var_names.ga_data)[0] =
+						 vim_strsave((char_u *)"this");
+	++dfunc->df_var_names.ga_len;
+
+	// In the constructor allocate memory for the object.
+	if ((ufunc->uf_flags & FC_NEW) == FC_NEW)
+	    generate_CONSTRUCT(&cctx, ufunc->uf_class);
+    }
+
     if (ufunc->uf_def_args.ga_len > 0)
     {
 	int	count = ufunc->uf_def_args.ga_len;
@@ -3500,14 +3554,19 @@ nextline:
     {
 	if (ufunc->uf_ret_type->tt_type == VAR_UNKNOWN)
 	    ufunc->uf_ret_type = &t_void;
-	else if (ufunc->uf_ret_type->tt_type != VAR_VOID)
+	else if (ufunc->uf_ret_type->tt_type != VAR_VOID
+		&& (ufunc->uf_flags & FC_NEW) != FC_NEW)
 	{
 	    emsg(_(e_missing_return_statement));
 	    goto erret;
 	}
 
 	// Return void if there is no return at the end.
-	generate_instr(&cctx, ISN_RETURN_VOID);
+	// For a constructor return the object.
+	if ((ufunc->uf_flags & FC_NEW) == FC_NEW)
+	    generate_instr(&cctx, ISN_RETURN_OBJECT);
+	else
+	    generate_instr(&cctx, ISN_RETURN_VOID);
     }
 
     // When compiled with ":silent!" and there was an error don't consider the
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -2029,6 +2029,7 @@ handle_debug(isn_T *iptr, ectx_T *ectx)
     for (ni = iptr + 1; ni->isn_type != ISN_FINISH; ++ni)
 	if (ni->isn_type == ISN_DEBUG
 		  || ni->isn_type == ISN_RETURN
+		  || ni->isn_type == ISN_RETURN_OBJECT
 		  || ni->isn_type == ISN_RETURN_VOID)
 	{
 	    end_lnum = ni->isn_lnum + (ni->isn_type == ISN_DEBUG ? 0 : 1);
@@ -2082,7 +2083,7 @@ execute_storeindex(isn_T *iptr, ectx_T *
     // Stack contains:
     // -3 value to be stored
     // -2 index
-    // -1 dict or list
+    // -1 dict, list, blob or object
     tv = STACK_TV_BOT(-3);
     SOURCING_LNUM = iptr->isn_lnum;
     if (dest_type == VAR_ANY)
@@ -2203,6 +2204,13 @@ execute_storeindex(isn_T *iptr, ectx_T *
 		return FAIL;
 	    blob_set_append(blob, lidx, nr);
 	}
+	else if (dest_type == VAR_CLASS || dest_type == VAR_OBJECT)
+	{
+	    long	    idx = (long)tv_idx->vval.v_number;
+	    object_T	    *obj = tv_dest->vval.v_object;
+	    typval_T	    *otv = (typval_T *)(obj + 1);
+	    otv[idx] = *tv;
+	}
 	else
 	{
 	    status = FAIL;
@@ -3001,6 +3009,18 @@ exec_instructions(ectx_T *ectx)
 	iptr = &ectx->ec_instr[ectx->ec_iidx++];
 	switch (iptr->isn_type)
 	{
+	    // Constructor, new() method.
+	    case ISN_CONSTRUCT:
+		// "this" is always the local variable at index zero
+		tv = STACK_TV_VAR(0);
+		tv->v_type = VAR_OBJECT;
+		tv->vval.v_object = alloc_clear(
+				       iptr->isn_arg.construct.construct_size);
+		tv->vval.v_object->obj_class =
+				       iptr->isn_arg.construct.construct_class;
+		tv->vval.v_object->obj_refcount = 1;
+		break;
+
 	    // execute Ex command line
 	    case ISN_EXEC:
 		if (exec_command(iptr) == FAIL)
@@ -4092,15 +4112,25 @@ exec_instructions(ectx_T *ectx)
 		    goto on_error;
 		break;
 
-	    // return from a :def function call without a value
+	    // Return from a :def function call without a value.
+	    // Return from a constructor.
 	    case ISN_RETURN_VOID:
+	    case ISN_RETURN_OBJECT:
 		if (GA_GROW_FAILS(&ectx->ec_stack, 1))
 		    goto theend;
 		tv = STACK_TV_BOT(0);
 		++ectx->ec_stack.ga_len;
-		tv->v_type = VAR_VOID;
-		tv->vval.v_number = 0;
-		tv->v_lock = 0;
+		if (iptr->isn_type == ISN_RETURN_VOID)
+		{
+		    tv->v_type = VAR_VOID;
+		    tv->vval.v_number = 0;
+		    tv->v_lock = 0;
+		}
+		else
+		{
+		    *tv = *STACK_TV_VAR(0);
+		    ++tv->vval.v_object->obj_refcount;
+		}
 		// FALLTHROUGH
 
 	    // return from a :def function call with what is on the stack
@@ -4193,7 +4223,7 @@ exec_instructions(ectx_T *ectx)
 		    CLEAR_FIELD(ea);
 		    ea.cmd = ea.arg = iptr->isn_arg.string;
 		    ga_init2(&lines_to_free, sizeof(char_u *), 50);
-		    define_function(&ea, NULL, &lines_to_free);
+		    define_function(&ea, NULL, &lines_to_free, NULL);
 		    ga_clear_strings(&lines_to_free);
 		}
 		break;
@@ -6018,6 +6048,11 @@ list_instructions(char *pfx, isn_T *inst
 
 	switch (iptr->isn_type)
 	{
+	    case ISN_CONSTRUCT:
+		smsg("%s%4d NEW %s size %d", pfx, current,
+			iptr->isn_arg.construct.construct_class->class_name,
+				  (int)iptr->isn_arg.construct.construct_size);
+		break;
 	    case ISN_EXEC:
 		smsg("%s%4d EXEC %s", pfx, current, iptr->isn_arg.string);
 		break;
@@ -6447,6 +6482,9 @@ list_instructions(char *pfx, isn_T *inst
 	    case ISN_RETURN_VOID:
 		smsg("%s%4d RETURN void", pfx, current);
 		break;
+	    case ISN_RETURN_OBJECT:
+		smsg("%s%4d RETURN object", pfx, current);
+		break;
 	    case ISN_FUNCREF:
 		{
 		    funcref_T		*funcref = &iptr->isn_arg.funcref;
@@ -6979,6 +7017,8 @@ tv2bool(typval_T *tv)
 	case VAR_ANY:
 	case VAR_VOID:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    break;
     }
     return FALSE;
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -235,6 +235,8 @@ compile_member(int is_slice, int *keepin
 	    case VAR_JOB:
 	    case VAR_CHANNEL:
 	    case VAR_INSTR:
+	    case VAR_CLASS:
+	    case VAR_OBJECT:
 	    case VAR_UNKNOWN:
 	    case VAR_ANY:
 	    case VAR_VOID:
--- a/src/vim9instr.c
+++ b/src/vim9instr.c
@@ -114,6 +114,24 @@ generate_instr_debug(cctx_T *cctx)
 }
 
 /*
+ * Generate an ISN_CONSTRUCT instruction.
+ * The object will have "size" members.
+ */
+    int
+generate_CONSTRUCT(cctx_T *cctx, class_T *cl)
+{
+    isn_T	*isn;
+
+    RETURN_OK_IF_SKIP(cctx);
+    if ((isn = generate_instr(cctx, ISN_CONSTRUCT)) == NULL)
+	return FAIL;
+    isn->isn_arg.construct.construct_size = sizeof(object_T)
+			       + cl->class_obj_member_count * sizeof(typval_T);
+    isn->isn_arg.construct.construct_class = cl;
+    return OK;
+}
+
+/*
  * If type at "offset" isn't already VAR_STRING then generate ISN_2STRING.
  * But only for simple types.
  * When "tolerant" is TRUE convert most types to string, e.g. a List.
@@ -163,6 +181,8 @@ may_generate_2STRING(int offset, int tol
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 			 to_string_error(type->tt_type);
 			 return FAIL;
     }
@@ -2403,6 +2423,7 @@ delete_instr(isn_T *isn)
 	case ISN_COMPARESPECIAL:
 	case ISN_COMPARESTRING:
 	case ISN_CONCAT:
+	case ISN_CONSTRUCT:
 	case ISN_COND2BOOL:
 	case ISN_DEBUG:
 	case ISN_DEFER:
@@ -2457,6 +2478,7 @@ delete_instr(isn_T *isn)
 	case ISN_REDIRSTART:
 	case ISN_RETURN:
 	case ISN_RETURN_VOID:
+	case ISN_RETURN_OBJECT:
 	case ISN_SHUFFLE:
 	case ISN_SLICE:
 	case ISN_SOURCE:
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -838,7 +838,7 @@ vim9_declare_scriptvar(exarg_T *eap, cha
     // parse type, check for reserved name
     p = skipwhite(p + 1);
     type = parse_type(&p, &si->sn_type_list, TRUE);
-    if (type == NULL || check_reserved_name(name) == FAIL)
+    if (type == NULL || check_reserved_name(name, NULL) == FAIL)
     {
 	vim_free(name);
 	return p;
@@ -1126,12 +1126,17 @@ static char *reserved[] = {
 };
 
     int
-check_reserved_name(char_u *name)
+check_reserved_name(char_u *name, cctx_T *cctx)
 {
     int idx;
 
     for (idx = 0; reserved[idx] != NULL; ++idx)
-	if (STRCMP(reserved[idx], name) == 0)
+	if (STRCMP(reserved[idx], name) == 0
+		// "this" can be used in an object method
+		&& !(STRCMP("this", name) == 0
+		    && cctx != NULL
+		    && cctx->ctx_ufunc != NULL
+		    && (cctx->ctx_ufunc->uf_flags & FC_OBJECT)))
 	{
 	    semsg(_(e_cannot_use_reserved_name), name);
 	    return FAIL;
--- a/src/vim9type.c
+++ b/src/vim9type.c
@@ -29,7 +29,7 @@
  * Allocate memory for a type_T and add the pointer to type_gap, so that it can
  * be easily freed later.
  */
-    static type_T *
+    type_T *
 get_type_ptr(garray_T *type_gap)
 {
     type_T *type;
@@ -94,7 +94,12 @@ alloc_type(type_T *type)
     *ret = *type;
 
     if (ret->tt_member != NULL)
-	ret->tt_member = alloc_type(ret->tt_member);
+    {
+	// tt_member points to the class_T for VAR_CLASS and VAR_OBJECT
+	if (type->tt_type != VAR_CLASS && type->tt_type != VAR_OBJECT)
+	    ret->tt_member = alloc_type(ret->tt_member);
+    }
+
     if (type->tt_args != NULL)
     {
 	int i;
@@ -124,7 +129,11 @@ free_type(type_T *type)
 	    free_type(type->tt_args[i]);
 	vim_free(type->tt_args);
     }
-    free_type(type->tt_member);
+
+    // for an object and class tt_member is a pointer to the class
+    if (type->tt_type != VAR_OBJECT && type->tt_type != VAR_CLASS)
+	free_type(type->tt_member);
+
     vim_free(type);
 }
 
@@ -1203,6 +1212,8 @@ equal_type(type_T *type1, type_T *type2,
 	case VAR_JOB:
 	case VAR_CHANNEL:
 	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
 	    break;  // not composite is always OK
 	case VAR_LIST:
 	case VAR_DICT:
@@ -1451,6 +1462,8 @@ vartype_name(vartype_T type)
 	case VAR_LIST: return "list";
 	case VAR_DICT: return "dict";
 	case VAR_INSTR: return "instr";
+	case VAR_CLASS: return "class";
+	case VAR_OBJECT: return "object";
 
 	case VAR_FUNC:
 	case VAR_PARTIAL: return "func";
--- a/src/viminfo.c
+++ b/src/viminfo.c
@@ -1370,6 +1370,8 @@ write_viminfo_varlist(FILE *fp)
 		    case VAR_JOB:
 		    case VAR_CHANNEL:
 		    case VAR_INSTR:
+		    case VAR_CLASS:
+		    case VAR_OBJECT:
 				     continue;
 		}
 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);