method.skeleton {methods} | R Documentation

## Create a Skeleton File for a New Method

### Description

This function writes a source file containing a call to `setMethod` to define a method for the generic function and signature supplied. By default the method definition is in line in the call, but can be made an external (previously assigned) function.

### Usage

    method.skeleton(generic, signature, file, external = FALSE, where)

### Arguments

`generic` | the character string name of the generic function, or the generic function itself. In the first case, the function need not currently be a generic, as it would not for the resulting call to `setMethod`.
`signature` | the method signature, as it would be given to `setMethod`
`file` | a character string name for the output file, or a writable connection. By default the generic function name and the classes in the signature are concatenated, with separating underscore characters. The file name should normally end in `".R"`.

To write multiple method skeletons to one file, open the file connection first and then pass it to `method.skeleton()` in multiple calls.

`external` | flag to control whether the function definition for the method should be a separate external object assigned in the source file, or included in line in the call to `setMethod`. If supplied as a character string, this will be used as the name for the external function; by default the name concatenates the generic and signature names, with separating underscores.
`where` | The environment in which to look for the function; by default, the top-level environment of the call to `method.skeleton`.

### Value

The `file` argument, invisibly, but the function is used for its side effect.

### See Also

`setMethod`, `package.skeleton`

### Examples

    setClass("track", slots = c(x ="numeric", y="numeric"))
    method.skeleton("show", "track")            ## writes show_track.R
    method.skeleton("Ops", c("track", "track")) ## writes "Ops_track_track.R"

    ## write multiple method skeletons to one file
    con <- file("./Math_track.R", "w")
    method.skeleton("Math", "track", con)
    method.skeleton("exp", "track", con)
    method.skeleton("log", "track", con)
    close(con)

[Package methods version 3.4.2 Index]