patch 9.1.0148: Vim9: can't call internal methods with objects
Problem: Vim9: can't call internal methods with objects
Solution: Add support for empty(), len() and string() function
calls for objects (Yegappan Lakshmanan)
closes: #14129
Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/vim9class.txt b/runtime/doc/vim9class.txt
index ba821c1..a00a5b7 100644
--- a/runtime/doc/vim9class.txt
+++ b/runtime/doc/vim9class.txt
@@ -1,4 +1,4 @@
-*vim9class.txt* For Vim version 9.1. Last change: 2024 Jan 12
+*vim9class.txt* For Vim version 9.1. Last change: 2024 Mar 03
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -710,6 +710,32 @@
*E1330*
Some types cannot be used, such as "void", "null" and "v:none".
+Builtin Object Methods ~
+ *builtin-object-methods*
+Some of the builtin functions like |empty()|, |len()| and |string()| can be
+used with an object. An object can implement a method with the same name as
+these builtin functions to return an object-specific value.
+
+ *E1412*
+The following builtin methods are supported:
+ *object-empty()*
+ empty() Invoked by the |empty()| function to check whether an object is
+ empty. If this method is missing, then true is returned. This
+ method should not accept any arguments and must return a boolean.
+ *object-len()*
+ len() Invoked by the |len()| function to return the length of an
+ object. If this method is missing in the class, then an error is
+ given and zero is returned. This method should not accept any
+ arguments and must return a number.
+ *object-string()*
+ string() Invoked by the |string()| function to get a textual
+ representation of an object. Also used by the |:echo| command
+ for an object. If this method is missing in the class, then a
+ built-in default textual representation is used. This method
+ should not accept any arguments and must return a string.
+
+ *E1413*
+A class method cannot be used as a builtin method.
Defining an interface ~
*Interface* *:interface* *:endinterface*