title: Passing values between functions in an R package
body: <p>In an R package, let's say we have two functions. One is setting some parameters; the other one is using those parameters. How can I build such a pattern in R. It is similar to event-driven applications. But I am not sure if it is possible in R or not.</p>
  <p>For example:
  If we run set_param( a=10), whenever we run print_a.R, it prints 10, and incase of running set_param(a=20), it prints 20.
  I need a solution without assigning value to the global environment because CRAN checks raise notes.</p>