getClass {methods}R Documentation

Get Class Definition

Description

Get the definition of a class.

Usage

getClass(Class, .Force = FALSE)
getClassDef(Class, where=-1)

Arguments

Class the character-string name of the class.
.Force if TRUE, return NULL if the class is undefined; otherwise, an undefined class results in an error.
where

{ where to search for the definition; by default, anywhere on the current search list.}

Details

A call to getClass returns the complete definition of the class supplied as a string, including all slots, etc. in classes that this class extends. A call to getClassDef returns the definition of the class from that database, unadorned. It's usually getClass you want.

The statement that getClass fails if the class is undefined is not quite true at the moment. A few special vector types and informally defined classes are allowed, and getClass returns NULL for these. But don't count on it; eventually these holes in the class system should be plugged.

In any case, if you really want to know whether a class is formally defined, call isClass.

Value

The object defining the class. This is an object of class "classRepEnvironment". However, do not deal with the contents of the object directly unless you are very sure you know what you're doing. Even then, it is nearly always better practice to use functions such as setClass and setIs. Messing up a class object will cause great confusion.

Author(s)

John Chambers

References

The web page http://www.omegahat.org/RSMethods/index.html is the primary documentation.

The functions in this package emulate the facility for classes and methods described in Programming with Data, (John M. Chambers, Springer, 1998). See this book for further details and examples.

See Also

Classes, setClass, isClass.

Examples

getClass("numeric") ## a built in class



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