The function ExposeAttribute creates an S3 object that
exposes all attributes of any R object, by making them accessible via
methods $ and/or $<-.
ExposeAttribute(object, ..., .MODE = "rw", .VALUE = FALSE)attr_mode(x)
attr_mode(x) <- value
ExposeAttribute returns an S3 object of class ExposeAttribute.
any R object whose attributes need to be exposed
attributes, and optionally their respective values or
access permissions.
See argument value of attr_mode for details on the
way of specifying these.
access mode:
(read-only) only method $ is defined
(write-only) only method $<- is defined
(read-write) both methods $ and $<-
are defined
logical that indicates if the values of named arguments
in ... should be considered as attribute assignments,
i.e. that the result object has these attributes set with the specified values.
In this case all these attributes will have the access permission
as defined by argument .MODE.
an ExposeAttribute object
replacement value for mode.
It can be NULL to remove the ExposeAttribute wrapper,
a single character string to define a permission for all atributes
(e.g., 'rw' or 'r'), or a list specifying access permission
for specific attributes or classes of attributes defined by regular expressions.
For example, list(a='r', b='w', `blabla.*`='rw') set attribute 'a'
as read-only, attribute 'b' as write-only, all attributes that start with
'blabla' in read-write access.