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R.oo (version 1.2.7)

extend.Object: Extends another class

Description

Simply speaking this method "extends another class". What is actually happening is that it creates an instance of class name ...className, by taking another Object instance and add ...className to the class list and also add all the named values in ... as fields to the new instance. The method should be used by the constructor of a class and nowhere else.

Usage

## S3 method for class 'Object}(this, ...className, ..., ...fields=NULL)':
extendundefined

 ...className{The name of new class.}
   ...{Named values representing the fields of the new instance.}
   ...fields{An optional named list of fields.  This makes it possible
     to specify a set of fields using a list object.}

 Returns an Object of class className.

 
The reason for the strange name of argument "...className" is that
   if one tries to set a field with a name that is a prefix of the name of
   this arguments and one at the same time does not specify the name of this
   argument one would run into strange errors. For instance, try
   extend(Object(), "MyClass", ...c=0).


 
Field modifiers
{
   It is possible to specify modifiers to some of the fields.  Currently it
   is only the cached modifier that is recognized.  A field that is
   cached will be assigned NULL when *clearCache()
   (or *gc()) is called.  To specify a modifier, append a comma
   separated list of modifiers followed by a colon, e.g. "cached:foo".
 }

 For a complete example see help(Object).

 [object Object]

 For more information see Object.

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Arguments