Please keep in mind that while lazy evaluation and delayedAssign are
documented parts of the language, promises are an internal
implementation mechanism that is subject to change. In particular the
fact that substitute behaves the way it does is a coincidence of the
current implementation that may
Is there some way of displaying the expression and evaluation environment
associated with a promise? I have found the following:
> # first run these two commands to set up example
> e <- new.env()
> delayedAssign("y", x*x, assign.env = e)
> # method 1. shows expression but not evaluation envir
