R: Give the formal arguments of an S4 method

S4formals {Rdpack} | R Documentation

## Give the formal arguments of an S4 method

### Description

Give the formal arguments of an S4 method.

### Usage

    S4formals(fun, ...)

### Arguments

`fun` | name of an S4 generic, a string, or the method, see Details.
`...` | further arguments to be passed to `getMethod`, see Details.

### Details

`S4formals` gives the formal arguments of the requested method. If `fun` is not of class `methodDefinition`, it calls `getMethods`, passing on all arguments.

Typically, `fun` is the name of a generic function and the second argument is the signature of the method as a character vector. Alternatively, `fun` may be the method itself (e.g. obtained previously from `getMethod`) and in that case the `"\dots"` arguments are ignored. See `getMethod` for full details and other acceptable arguments.

### Value

a pairlist, like `formals`

### Note

Arguments of a method after those used for dispatch may be different from the arguments of the generic. The latter may simply have a `"\dots"` argument there.

todo: there should be a similar function in the "methods" package, or at least use a documented feature to extract it.

### Author(s)

Georgi N. Boshnakov

### Examples

    require(stats4) # makes plot() S4 generic

    S4formals("plot", c(x = "profile.mle", y = "missing"))

    m1 <- getMethod("plot", c(x = "profile.mle", y = "missing"))
    S4formals(m1)

[Package Rdpack version 0.10-1 Index]