How can one figure out the current plan?

[jan-glx]

For debugging the setup (.future.R) it would be useful to have an easy way to check the current plan.
Did I miss this in the documentation? It took me a while to figure out that its currently possible with environment(plan)$stack.

[HenrikBengtsson]

Just call plan() without arguments, e.g.

> plan()
sequential:
- args: function (..., envir = parent.frame())
- tweaked: FALSE
- call: NULL

It's documented in https://future.futureverse.org/reference/plan.html#value, but now I see the docs could be more clear about this.

If you have a nested setup, you can get the list of future plans, using the non-documented(?) plan("list"):

> plan(list(sequential, multisession))

> plan()
sequential:
- args: function (..., envir = parent.frame())
- tweaked: FALSE
- call: plan(list(sequential, multisession))

> plan("list")
List of future strategies:
1. sequential:
   - args: function (..., envir = parent.frame())
   - tweaked: FALSE
   - call: plan(list(sequential, multisession))
2. multisession:
   - args: function (..., workers = availableCores(), lazy = FALSE, rscript_libs = .libPaths(), envir = parent.frame())
   - tweaked: FALSE
   - call: plan(list(sequential, multisession))

I forgot the reason, but I think I created plan("list") as a hidden beta feature, and then I've seem to have forgotten to mention it in the help page.

[jan-glx]

Hidden in plain sight 😅. (I think I might have tried and got confused because it returned the sequential, the "default" plan, while expecting batchtools_lsf, thus jumping to the conclusions that no arguments just set the default plan.) Thanks for the prompt reply!