Learn R Programming
utils (version 3.3)

isS3method: Is 'method' the Name of an S3 Method?

Description

Checks if method is the name of a valid / registered S3 method. Alternatively, when f and class are specified, it is checked if f is the name of an S3 generic function and paste(f, class, sep=".") is a valid S3 method.

Usage

isS3method(method, f, class, envir = parent.frame())

Arguments

method
a character string, typically of the form ".". If omitted, f and class have to be specified instead.
f
optional character string, typically specifying an S3 generic function. Used, when method is not specified.
class
optional character string, typically specifying an S3 class name. Used, when method is not specified.
envir
the environment in which the method and its generic are searched first, as in getS3method().

Value

See Also

methods, getS3method.

Examples

Run this code
isS3method("t")           # FALSE - it is an S3 generic
isS3method("t.default")   # TRUE
isS3method("t.ts")        # TRUE
isS3method("t.test")      # FALSE
isS3method("t.data.frame")# TRUE
isS3method("t.lm")        # FALSE - not existing
isS3method("t.foo.bar")   # FALSE - not existing
stopifnot(
  !isS3method("t"), !isS3method("t.test"), !isS3method("qr.coef"), !isS3method("sort.list"),
  isS3method("t.default"), isS3method("t.ts"), isS3method("t.data.frame"),
  !isS3method("t.lm"), !isS3method("t.foo.bar"))

Run the code above in your browser using DataLab