body(body)
f <- function(x) x^5
body(f) <- quote(5^x)
## or equivalently body(f) <- expression(5^x)
f(3) # = 125
body(f)
## creating a multi-expression body
e <- expression(y <- x^2, return(y)) # or a list
body(f) <- as.call(c(as.name("{"), e))
f
f(8)
## Using substitute() may be simpler than 'as.call(c(as.name("{",..)))':
stopifnot(identical(body(f), substitute({ y <- x^2; return(y) })))
Run the code above in your browser using DataLab