BasicClasses {methods} | R Documentation |
Formal classes exist corresponding to the basic R object types, allowing these types to be used in method signatures, as slots in class definitions, and to be extended by new classes.
### The following are all basic vector classes.
### They can appear as class names in method signatures,
### in calls to as(), is(), and new().
"character"
"complex"
"double"
"expression"
"integer"
"list"
"logical"
"numeric"
"single"
"raw"
### the class
"vector"
### is a virtual class, extended by all the above
### the class
"S4"
### is an object type for S4 objects that do not extend
### any of the basic vector classes. It is a virtual class.
### The following are additional basic classes
"NULL" # NULL objects
"function" # function objects, including primitives
"externalptr" # raw external pointers for use in C code
"ANY" # virtual classes used by the methods package itself
"VIRTUAL"
"missing"
Objects can be created by calls of the form new(Class, ...)
,
where Class
is the quoted class name, and the remaining
arguments if any are objects to be interpreted as vectors of this
class. Multiple arguments will be concatenated.
The class "expression"
is slightly odd, in that the ...
arguments will not be evaluated; therefore, don't enclose them
in a call to quote()
.
Class "vector"
, directly.
Methods are defined to coerce arbitrary objects to
these classes, by calling the corresponding basic function, for
example, as(x, "numeric")
calls as.numeric(x)
.