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\name{methods}
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\title{List Methods for S3 Generic Functions or Classes}
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\alias{methods}
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\alias{print.MethodsFunction}
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\description{
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List all available methods for an S3 generic function, or all
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methods for a class.
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}
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\usage{
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methods(generic.function, class)
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}
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\arguments{
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\item{generic.function}{a generic function, or a character string naming a
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generic function.}
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\item{class}{a symbol or character string naming a class: only used if
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\code{generic.function} is not supplied.}
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}
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\value{
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An object of class \code{"MethodsFunction"}, a
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character vector of function names with an \code{"info"} attribute.
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There is a \code{print} method which marks with an asterisk any
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methods which are not visible: such functions can be examined by
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\code{\link{getS3method}} or \code{\link{getAnywhere}}.
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The \code{"info"} attribute is a data frame, currently with a
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logical column, \code{visible} and a factor column \code{from}
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(indicating where the methods were found).
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}
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\details{
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Function \code{methods} can be used to find out about the methods for
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a particular generic function or class. The functions listed are those
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which \emph{are named like methods} and may not actually be methods
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(known exceptions are discarded in the code). Note that the listed
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methods may not be user-visible objects, but often help will be
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available for them.
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If \code{class} is used, we check that a matching generic can be found
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for each user-visible object named.
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}
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\note{
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This scheme is called \emph{S3} (S version 3). For new projects,
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it is recommended to use the more flexible and robust \emph{S4} scheme
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provided in the \pkg{methods} package. Functions can have both S3
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and S4 methods, and function \code{\link[methods]{showMethods}} will
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list the S4 methods (possibly none).
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The original \code{methods} function was written by Martin Maechler.
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}
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\seealso{
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\code{\link{S3Methods}}, \code{\link[base]{class}}, \code{\link{getS3method}}
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}
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\references{
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Chambers, J. M. (1992)
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\emph{Classes and methods: object-oriented programming in S.}
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Appendix A of \emph{Statistical Models in S}
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eds J. M. Chambers and T. J. Hastie, Wadsworth \& Brooks/Cole.
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}
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\examples{
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methods(summary)
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methods(class = "aov")
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methods("[[") ##- does not list the C-internal ones...
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methods("$") # currently none
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methods("$<-") # replacement function
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methods("+") # binary operator
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methods("Math") # group generic
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\dontrun{methods(print)
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}}
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\keyword{methods}
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