[R-pkg-devel] Problems with too much testing

My 2c is that if a package has actually tested something like that
(say, the ordering of a list's elements), then it is 100% likely that
a script out there depends on that behaviour too. 

I suspect this test is not intentional, and it really wouldn't make 
sense for a package to depend on the order of named list components.

  In other words, the

change is not inconsequential.  R users are in debt to package
developers but I think it behoves us to take special care not to
underestimate the work involved when a package's behaviour changes.

There's a difference between internal implementation changes and 
external behaviour changes.  For example, there are clear warnings not 
to use un-exported functions (via :::), and a package that did that 
would not be accepted on CRAN.

What I'm asking for are suggestions for ways to hide internal layouts of 
objects from users.  That seems a lot harder.

Duncan Murdoch