Internal Generic Functions

Description

Many R-internal functions are generic and allow methods to be written for.

Details

The following primitive and internal functions are generic, i.e., you can write methods for them:

[, [[, $, [<-, [[<-, $<-,

length, length<-, dimnames, dimnames<-, dim, dim<-, names, names<-, levels<-,

c, unlist, cbind, rbind,

as.character, as.complex, as.double, as.integer, as.logical, as.raw, as.vector, is.array, is.matrix, is.na, is.nan, is.numeric, rep and seq.int (which dispatches methods for "seq").

In addition, is.name is a synonym for is.symbol and dispatches methods for the latter.

Note that all of the group generic functions are also internal/primitive and allow methods to be written for them.

.S3PrimitiveGenerics is a character vector listing the primitives which are internal generic and not group generic. Currently as.vector, cbind, rbind and unlist are the internal non-primitive functions which are internally generic.

For efficiency, internal dispatch only occurs on objects, that is those for which is.object returns true.

See Also

methods for the methods which are available.