Support cache(dataset) in addition to cache("dataset") about projecttemplate

[johnmyleswhite]

I am very strongly opposed to that idiom, as would be Hadley Wickham: http://adv-r.had.co.nz/Computing-on-the-language.html

[KentonWhite]

In this case, we run into the problem:

vars <- ls()
cache(vars)

Expected behavior is to cache all of the variables. What will happen is that the variable vars will be cached, which is just a list of the current variables in the environment.

I also want this feature but it looks like it has potential for unexpected behavior.

[krlmlr]

This idiom is also used in the save function. There are two parameters: ... and list, the latter takes a list of variable names.

Currently, cache is not vectorized at all.

[KentonWhite]

I like that compromise. Having the cache interface similar to save makes sense to me.

[krlmlr]

I can't support this feature anymore. @KentonWhite: Please feel free to reopen.