R: Create a Skeleton File for a New Method

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.

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)