body {base}R Documentation

Access to and Manipulation of the Body of a Function

Description

Get or set the body of a function.

Usage

body(fun = sys.function(sys.parent()))
body(fun, envir = environment(fun)) <- value

Arguments

fun a function object, or see ‘Details’.
envir environment in which the function should be defined.
value an object, usually a language object: see section ‘Value’.

Details

For the first form, fun can be a character string naming the function to be manipulated, which is searched for from the parent environment. If it is not specified, the function calling body is used.

To set the value to a list call the replacement function with value a length-one list containing the desired value.

Value

body returns the body of the function specified. This is normally a language object, most often a call to {, but it can also be an object (e.g. pi) to be the return value of the function.
The replacement form sets the body of a function to the object on the right hand side, and (potentially) resets the environment of the function. If value is of class "expression" or a length-one list, the first element is used as the body. For expressions (but not lists) any additional elements are ignored, with a warning.

See Also

alist, args, function.

Examples

body(body)
f <- function(x) x^5
body(f) <- expression(5^x)
## or equivalently  body(f) <- list(quote(5^x))
f(3) # = 125
body(f)

[Package base version 2.8.1 Index]