isClass(Class, formal=TRUE, where)
getClasses(where, inherits = missing(where))
findClass(Class, where, unique = "")
removeClass(Class, where, resolve.msg = getOption("removeClass.msg", default=TRUE))
resetClass(Class, classDef, where)
sealClass(Class, where)packageSlot of the character string.environment in which to modify or
remove the definition. Defaults to the top-level environment of the
calling function (the global environment for ordinary computations,
but the environment or namespace of a package in the source for a
package). When searching for class definitions, where defines where to
do the search, and the default is to search from the top-level
environment or namespace of the caller to this function.
logical indicating if a formal definition
is required.findClass expects a unique location for the
class, unique is a character string explaining the purpose
of the search (and is used in warning and error messages). By
default, multiple locations are possible and the function always
returns a list.
getClasses, should the value
returned include all parent environments of where, or that
environment only? Defaults to TRUE if where is
omitted, and to FALSE otherwise.
resetClass, the optional class
definition (but usually it's better for Class to be the
class definition, and to omit classDef).
removeClass:where if this argument is supplied; if not,
removeClass will search for a definition, starting in the
top-level environment of the call to removeClass, and
remove the (first) definition found.
isClass:formal is for compatibility and is ignored.)
getClasses:where. If
called with no argument, all the classes visible from the
calling function (if called from the top-level, all the classes
in any of the environments on the search list). The
inherits argument can be used to search a particular
environment and all its parents, but usually the default setting
is what you want.
findClass:Class is found. If
where is supplied, this is an environment (or namespace)
from which the search takes place; otherwise the top-level
environment of the caller is used. If unique is supplied
as a character string, findClass returns a single
environment or position. By default, it always returns a list.
The calling function should select, say, the first element as a
position or environment for functions such as get. If unique is supplied as a character string,
findClass will warn if there is more than one definition
visible (using the string to identify the purpose of the call),
and will generate an error if no definition can be found.
resetClass:setClass.This function is called when aspects of the class definition are changed. You would need to call it explicitly if you changed the definition of a class that this class extends (but doing that in the middle of a session is living dangerously, since it may invalidate existing objects).
sealClass:setClass, but sometimes further changes have
to be made (e.g., by calls to setIs). If so, call
sealClass after all the relevant changes have been made.
Chambers, John M. (1998) Programming with Data Springer (For the original S4 version.)
setClassUnion,
Methods,
makeClassRepresentation