[Bioc-devel] BiocParallel: Best standards for passing locally assigned variables/functions, e.g. a bpExport()?

[Ryan]

On 11/4/13, 11:05 AM, Gabriel Becker wrote:
> As a side note, I'm not sure that existence of a symbol is sufficient (it
> certainly is necessary). What about situations where the symbol exists but
> is stale compared to the value in the parent? Are we sure that can never
> happen?
I think this is a different issue. We want to detect when a function 
depends on variables outside that function in the user's workspace, or 
variables defined in a pacakge that the user has loaded. I think we can 
assume that R child processes will be of the same version with the same 
set of installed packages, so package-defined variables will not have 
different values in child processes. For user variables, I think the 
goal should be to prevent (or at least highly discourage) dependencies 
on them entirely, so I don't think it matters what their value may be in 
the child. I realize this is somewhat counter to the question that 
started this thread, which was about exporting variables to the 
children, but I think it is the most straightforward approach. As I 
believe someone noted earlier in the thread, Henrik's original problem 
of a recursive function is properly solved by using the "Recall" function.

-Ryan