The R Project SVN – R – Diff – /trunk/src/library/methods/man/refClass.Rd



% File src/library/methods/man/refClass.Rd
% Part of the R package, http://www.R-project.org
% Copyright 2010-2014 R Core Team
% Distributed under GPL 2 or later
 
\name{ReferenceClasses}
\title{Objects With Fields Treated by Reference (OOP-style)}
\alias{ReferenceClasses}

See the section on \dQuote{Implementation} for the internal mechanism
used by accessor functions.
 
Note that fields are distinct from
the slots, if any, in the object.  Slots are, as always, handled by
standard \R{} object management.
It is not generally a good idea to mix slots and fields in the same
class; this confuses the distinction in behavior between reference
classes and regular S4 classes.  See the comments in the
\dQuote{Implementation} section.
}

used to access fields and other methods.
In particular, methods should not use non-exported entries in the
package's namespace, because the methods may be inherited by a
reference class in another package.
 
Methods for \code{$initialize()} %$
have special requirements.  See the comments in the \dQuote{Value}
section.
 
Reference methods can not themselves be generic functions; if you want
additional function-based method dispatch, write a separate generic

for any object from the relevant class.
In a method for this class, the field can be accessed by the name
\code{data}.
A field that is not locked can be set by an expression of the form
\code{x$data <- value}.%$
Inside a method, a field can be assigned by an expression of the form
\code{x <<- value}.
Note the \link[=assignOps]{non-local assignment} operator.
The standard \R interpretation of this operator works to assign it in
the environment of the object.
If the field has an accessor function defined, getting and setting

The R Project SVN R

(root)/trunk/src/library/methods/man/refClass.Rd @ 63243 – Rev 66540 → 66564

Rev 66540		Rev 66564
Line 1...		Line 1...
1	`% File src/library/methods/man/refClass.Rd`	1	`% File src/library/methods/man/refClass.Rd`
2	`% Part of the R package, http://www.R-project.org`	2	`% Part of the R package, http://www.R-project.org`
3	`% Copyright 2010-2 R Core Team`	3	`% Copyright 2010-2014 R Core Team`
4	`% Distributed under GPL 2 or later`	4	`% Distributed under GPL 2 or later`
5		5
6	`\name{ReferenceClasses}`	6	`\name{ReferenceClasses}`
7	`\title{Objects With Fields Treated by Reference (OOP-style)}`	7	`\title{Objects With Fields Treated by Reference (OOP-style)}`
8	`\alias{ReferenceClasses}`	8	`\alias{ReferenceClasses}`
Line 71...		Line 71...
71	`See the section on \dQuote{Implementation} for the internal mechanism`	71	`See the section on \dQuote{Implementation} for the internal mechanism`
72	`used by accessor functions.`	72	`used by accessor functions.`
73		73
74	`Note that fields are distinct from`	74	`Note that fields are distinct from`
75	`the slots, if any, in the object. Slots are, as always, handled by`	75	`the slots, if any, in the object. Slots are, as always, handled by`
76	`standard \R{} object management.`	76	`standard \R{} object management.`
77	`It is not generally a good idea to mix slots and fields in the same`	77	`It is not generally a good idea to mix slots and fields in the same`
78	`class; this confuses the distinction in behavior between reference`	78	`class; this confuses the distinction in behavior between reference`
79	`classes and regular S4 classes. See the comments in the`	79	`classes and regular S4 classes. See the comments in the`
80	`\dQuote{Implementation} section.`	80	`\dQuote{Implementation} section.`
81	`}`	81	`}`
Line 283...		Line 283...
283	`used to access fields and other methods.`	283	`used to access fields and other methods.`
284	`In particular, methods should not use non-exported entries in the`	284	`In particular, methods should not use non-exported entries in the`
285	`package's namespace, because the methods may be inherited by a`	285	`package's namespace, because the methods may be inherited by a`
286	`reference class in another package.`	286	`reference class in another package.`
287		287
288	`Methods for \code{$initialze()} %$`	288	`Methods for \code{$initialize()} %$`
289	`have special requirements. See the comments in the \dQuote{Value}`	289	`have special requirements. See the comments in the \dQuote{Value}`
290	`section.`	290	`section.`
291		291
292	`Reference methods can not themselves be generic functions; if you want`	292	`Reference methods can not themselves be generic functions; if you want`
293	`additional function-based method dispatch, write a separate generic`	293	`additional function-based method dispatch, write a separate generic`
Line 631...		Line 631...
631	`for any object from the relevant class.`	631	`for any object from the relevant class.`
632	`In a method for this class, the field can be accessed by the name`	632	`In a method for this class, the field can be accessed by the name`
633	`\code{data}.`	633	`\code{data}.`
634	`A field that is not locked can be set by an expression of the form`	634	`A field that is not locked can be set by an expression of the form`
635	`\code{x$data <- value}.%$`	635	`\code{x$data <- value}.%$`
636	`Inside a method, a field can be assigned by an expresion of the form`	636	`Inside a method, a field can be assigned by an expression of the form`
637	`\code{x <<- value}.`	637	`\code{x <<- value}.`
638	`Note the \link[=assignOps]{non-local assignment} operator.`	638	`Note the \link[=assignOps]{non-local assignment} operator.`
639	`The standard \R interpretation of this operator works to assign it in`	639	`The standard \R interpretation of this operator works to assign it in`
640	`the environment of the object.`	640	`the environment of the object.`
641	`If the field has an accessor function defined, getting and setting`	641	`If the field has an accessor function defined, getting and setting`