View the source of an R package

Question

Is there an easy way to view the source of an R package (or a method in a package), from within the interactive environment?

Answer 1

Just enter the name of a function/method without parentheses:

R> base::rev.default 
function (x) 
if (length(x)) x[length(x):1L] else x
<environment: namespace:base>

See also R-Help Desk - Accessing the Sources in R News Volume 6/4, October 2006.