# NOT RUN {
a <- b <- c <- NA_real_
# An sequential future
plan(sequential)
f <- future({
a <- 7
b <- 3
c <- 2
a * b * c
})
y <- value(f)
print(y)
str(list(a = a, b = b, c = c)) ## All NAs
# A sequential future with lazy evaluation
plan(sequential)
f <- future({
a <- 7
b <- 3
c <- 2
a * b * c
}) %lazy% TRUE
y <- value(f)
print(y)
str(list(a = a, b = b, c = c)) ## All NAs
# A multicore future (specified as a string)
plan("multicore")
f <- future({
a <- 7
b <- 3
c <- 2
a * b * c
})
y <- value(f)
print(y)
str(list(a = a, b = b, c = c)) ## All NAs
## Multisession futures gives an error on R CMD check on
## Windows (but not Linux or macOS) for unknown reasons.
## The same code works in package tests.
# }
# NOT RUN {
# A multisession future (specified via a string variable)
plan("future::multisession")
f <- future({
a <- 7
b <- 3
c <- 2
a * b * c
})
y <- value(f)
print(y)
str(list(a = a, b = b, c = c)) ## All NAs
# }
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