(1) list[…]<- I had posted this over a decade ago on r-help. Since then it has been added to the gsubfn package. It does not require a special operator but does require that the left hand side be written using list[...]
like this:
library(gsubfn) # need 0.7-0 or later
list[a, b] <- functionReturningTwoValues()
If you only need the first or second component these all work too:
list[a] <- functionReturningTwoValues()
list[a, ] <- functionReturningTwoValues()
list[, b] <- functionReturningTwoValues()
(Of course, if you only needed one value then functionReturningTwoValues()[[1]]
or functionReturningTwoValues()[[2]]
would be sufficient.)
See the cited r-help thread for more examples.
(2) with If the intent is merely to combine the multiple values subsequently and the return values are named then a simple alternative is to use with
:
myfun <- function() list(a = 1, b = 2)
list[a, b] <- myfun()
a + b
# same
with(myfun(), a + b)
(3) attach Another alternative is attach:
attach(myfun())
a + b
ADDED: with
and attach