enable use of old module versions in new workflows

[goldingn]

At some point users may want to use old module versions in a new workflow, for example to compare what's changed in the new version, or to set up automated scripts that they can be confident won't change if the module does.

I can't think of any very elegant interface to this. The best I can think of is modifying the parsing of modules to allow a special character, like:

w <- workflow(occurrence = [email protected],
              covariate = Bioclim(resolution = 5)@0.1,
              ...)

or

w <- workflow(occurrence = AnophelesPlumbeus[0.1],
              covariate = Bioclim[0.1](resolution = 5),
              ...)

what do you think?

[AugustT]

Could we add another default argument?

w <- workflow(occurrence = AnophelesPlumbeus(version = 0.1),
              covariate  = Bioclim(version = 0.1, resolution = 5),
              ...)

[AugustT]

Could also require user to load module before:

LoadModule('Biolim', version = 0.1)
w <- workflow(occurrence = AnophelesPlumbeus,
              covariate  = Bioclim(resolution = 5),
              ...)