patch 9.0.1909: Vim9: problem calling class method from other class
Problem: Vim9: problem calling class method from other class
Solution: Fix this problem, fix readonly object access, update error
messages.
Calling a class method from another method without the class name prefix
doesn't work properly.
A readonly object variable is modifiable outside the class using a
nested object assignment.
Remove the unused E1338 error message.
Update error messages.
closes: #13116
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>
diff --git a/runtime/doc/tags b/runtime/doc/tags
index 907d290..b754f08 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -4418,13 +4418,11 @@
E1326 vim9class.txt /*E1326*
E1327 vim9class.txt /*E1327*
E1328 vim9class.txt /*E1328*
-E1329 vim9class.txt /*E1329*
E133 userfunc.txt /*E133*
E1330 vim9class.txt /*E1330*
E1331 vim9class.txt /*E1331*
E1332 vim9class.txt /*E1332*
E1333 vim9class.txt /*E1333*
-E1334 vim9class.txt /*E1334*
E1335 vim9class.txt /*E1335*
E1336 options.txt /*E1336*
E1337 vim9class.txt /*E1337*
@@ -4458,9 +4456,27 @@
E1362 vim9class.txt /*E1362*
E1363 vim9class.txt /*E1363*
E1364 recover.txt /*E1364*
+E1365 vim9class.txt /*E1365*
+E1366 vim9class.txt /*E1366*
+E1367 vim9class.txt /*E1367*
+E1368 vim9class.txt /*E1368*
+E1369 vim9class.txt /*E1369*
E137 starting.txt /*E137*
E1370 vim9class.txt /*E1370*
+E1371 vim9class.txt /*E1371*
+E1372 vim9class.txt /*E1372*
+E1373 vim9class.txt /*E1373*
+E1374 vim9class.txt /*E1374*
+E1375 vim9class.txt /*E1375*
+E1376 vim9class.txt /*E1376*
+E1377 vim9class.txt /*E1377*
+E1378 vim9class.txt /*E1378*
+E1379 vim9class.txt /*E1379*
E138 starting.txt /*E138*
+E1380 vim9class.txt /*E1380*
+E1381 vim9class.txt /*E1381*
+E1382 vim9class.txt /*E1382*
+E1383 vim9class.txt /*E1383*
E139 message.txt /*E139*
E140 message.txt /*E140*
E1400 builtin.txt /*E1400*
@@ -6367,7 +6383,7 @@
cino-} indent.txt /*cino-}*
cinoptions-values indent.txt /*cinoptions-values*
class vim9class.txt /*class*
-class-function vim9class.txt /*class-function*
+class-method vim9class.txt /*class-method*
clear-undo undo.txt /*clear-undo*
clearmatches() builtin.txt /*clearmatches()*
client-server remote.txt /*client-server*
diff --git a/runtime/doc/vim9class.txt b/runtime/doc/vim9class.txt
index 20ad4bb..c106bb6 100644
--- a/runtime/doc/vim9class.txt
+++ b/runtime/doc/vim9class.txt
@@ -1,4 +1,4 @@
-*vim9class.txt* For Vim version 9.0. Last change: 2023 Mar 22
+*vim9class.txt* For Vim version 9.0. Last change: 2023 Sep 18
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -11,7 +11,7 @@
1. Overview |Vim9-class-overview|
2. A simple class |Vim9-simple-class|
-3. Class members and functions |Vim9-class-member|
+3. Class variables and methods |Vim9-class-member|
4. Using an abstract class |Vim9-abstract-class|
5. Using an interface |Vim9-using-interface|
6. More class details |Vim9-class|
@@ -139,11 +139,13 @@
Now you don't need the SetLnum(), SetCol() and SetPosition() methods, setting
"pos.lnum" directly above will no longer give an error.
- *E1334*
+ *E1326*
If you try to set an object member that doesn't exist you get an error: >
pos.other = 9
-< E1334: Object member not found: other ~
+< E1326: Member not found on object "TextPosition": other ~
+ *E1376*
+A object member cannot be accessed using the class name.
Private members ~
*E1332* *E1333*
@@ -176,9 +178,9 @@
endif
return this._lnum
enddef
-
-
+<
Private methods ~
+ *E1366*
If you want object methods to be accessible only from other methods of the
same class and not used from outside the class, then you can make them
private. This is done by prefixing the method name with an underscore: >
@@ -252,16 +254,17 @@
step the members of the parent class are done first. There is no need to call
"super()" or "new()" on the parent.
+ *E1365*
When defining the new() method the return type should not be specified. It
always returns an object of the class.
==============================================================================
-3. class members and functions *Vim9-class-member*
+3. Class Variables and Methods *Vim9-class-member*
- *:static* *E1337* *E1338*
+ *:static* *E1337* *E1338* *E1368*
Class members are declared with "static". They are used by the name without a
-prefix: >
+prefix in the class where they are defined: >
class OtherThing
this.size: number
@@ -275,6 +278,10 @@
Since the name is used as-is, shadowing the name by a function argument name
or local variable name is not allowed.
+ *E1374* *E1375*
+To access a class member outside of the class where it is defined, the class
+name prefix must be used. A class member cannot be accessed using an object.
+
Just like object members the access can be made private by using an underscore
as the first character in the name, and it can be made public by prefixing
"public": >
@@ -285,10 +292,11 @@
public static result: number # anybody can read and write
endclass
<
- *class-function*
-Class functions are also declared with "static". They have no access to
-object members, they cannot use the "this" keyword. >
-
+ *class-method*
+Class methods are also declared with "static". They can use the class
+variables but they have no access to the object variables, they cannot use the
+"this" keyword.
+>
class OtherThing
this.size: number
static totalSize: number
@@ -301,8 +309,9 @@
enddef
endclass
-Inside the class the function can be called by name directly, outside the
-class the class name must be prefixed: `OtherThing.ClearTotalSize()`.
+Inside the class the class method can be called by name directly, outside the
+class the class name must be prefixed: `OtherThing.ClearTotalSize()`. To use
+a super class method in a child class, the class name must be prefixed.
Just like object methods the access can be made private by using an underscore
as the first character in the method name: >
@@ -312,7 +321,7 @@
echo "Foo"
enddef
def Bar()
- OtherThing._Foo()
+ _Foo()
enddef
endclass
<
@@ -320,6 +329,31 @@
Note that constructors cannot be declared as "static", because they always
are.
+To access the class methods and class variables of a super class in an
+extended class, the class name prefix should be used just as from anywhere
+outside of the defining class: >
+
+ vim9script
+ class Vehicle
+ static nextID: number = 1000
+ static def GetID(): number
+ nextID += 1
+ return nextID
+ enddef
+ endclass
+ class Car extends Vehicle
+ this.myID: number
+ def new()
+ this.myID = Vehicle.GetID()
+ enddef
+ endclass
+<
+Class variables and methods are not inherited by a child class. A child class
+can declare a static variable or a method with the same name as the one in the
+super class. Depending on the class where the member is used the
+corresponding class member will be used. The type of the class member in a
+child class can be different from that in the super class.
+
==============================================================================
4. Using an abstract class *Vim9-abstract-class*
@@ -358,16 +392,19 @@
An abstract class is defined the same way as a normal class, except that it
does not have any new() method. *E1359*
- *abstract-method*
+ *abstract-method* *E1371* *E1372*
An abstract method can be defined in an abstract class by using the "abstract"
prefix when defining the function: >
abstract class Shape
abstract def Draw()
+ abstract static def SetColor()
endclass
-
+<
+ *E1373*
A class extending the abstract class must implement all the abstract methods.
-Class methods in an abstract class can also be abstract methods.
+The signature (arguments, argument types and return type) must be exactly the
+same. Class methods in an abstract class can also be abstract methods.
==============================================================================
@@ -409,9 +446,10 @@
return this.base * this.height / 2
enddef
endclass
-
+<
+ *E1348* *E1349* *E1367* *E1382* *E1383*
If a class declares to implement an interface, all the items specified in the
-interface must appear in the class, with the same types. *E1348* *E1349*
+interface must appear in the class, with the same types.
The interface name can be used as a type: >
@@ -422,7 +460,14 @@
for shape in shapes
echo $'the surface is {shape.Surface()}'
endfor
+<
+ *E1378* *E1379* *E1380*
+An interface can have only instance variables (read-only and read-write
+access) and methods. An interface cannot contain private variables, private
+methods, class variables and class methods.
+An interface can extend another interface using "extends". The sub-interface
+inherits all the instance variables and methods from the super interface.
==============================================================================
@@ -464,9 +509,12 @@
extends ClassName
implements InterfaceName, OtherInterface
specifies SomeInterface
-< *E1355*
+< *E1355* *E1369*
Each member and function name can be used only once. It is not possible to
-define a function with the same name and different type of arguments.
+define a function with the same name and different type of arguments. It is
+not possible to use a public and private member variable with the same name.
+A object variable name used in a super class cannot be reused in a child
+class.
Member Initialization ~
@@ -491,6 +539,10 @@
argument types and return type) must be exactly the same. The method of the
base class can be called by prefixing "super.".
+ *E1377*
+The access level of a method (public or private) in a child class should be
+the same as the super class.
+
Other object methods of the base class are taken over by the child class.
Class functions, including functions starting with "new", can be overruled,
@@ -523,18 +575,26 @@
Items in a class ~
- *E1318* *E1325* *E1326*
+ *E1318* *E1325*
Inside a class, in between `:class` and `:endclass`, these items can appear:
- An object member declaration: >
- this._memberName: memberType
- this.memberName: memberType
- public this.memberName: memberType
+ this._privateMemberName: memberType
+ this.readonlyMemberName: memberType
+ public this.readwriteMemberName: memberType
+- A class member declaration: >
+ static this._privateMemberName: memberType
+ static this.readonlyMemberName: memberType
+ static public this.readwriteMemberName: memberType
- A constructor method: >
def new(arguments)
def newName(arguments)
+- A class method: >
+ static def SomeMethod(arguments)
+ static def _PrivateMethod(arguments)
- An object method: >
def SomeMethod(arguments)
-< *E1329*
+ def _PrivateMethod(arguments)
+
For the object member the type must be specified. The best way is to do this
explicitly with ": {type}". For simple types you can also use an initializer,
such as "= 123", and Vim will see that the type is a number. Avoid doing this
@@ -573,6 +633,8 @@
The "Has" prefix can be used to make it easier to guess this is an interface
name, with a hint about what it provides.
An interface can only be defined in a |Vim9| script file. *E1342*
+An interface cannot "implement" another interface but it can "extend" another
+interface. *E1381*
null object ~