Using source() with future

[iferres]

Hi, I have a question regarding the use of source() to run a script. What would it be the best practices?

I'm organizing a very complex analysis, so I would like to send most of the heavy workloads to background sessions and return only specific variables.
For instance:

• script1.R

library(somepackage)
# bunch of things
x <- y + z
x

• script2.R

library(otherpackage)
# more things
a <- sqrt(b)
a

• analysis.R

library(future)
plan(multisession)

f_x <- future(source("script1.R"))
f_a <- future(source("script2.R"))

x <- value(f_x)
a <- value(f_a)

The analysis.R script is the main file. In principle I would expect to avoid loading somepackage and otherpackage to the main session. Any comments regarding the use of future in this scenario would be appreciated.

Thank you for the package, btw!

[iferres]

The general idea is to keep analysis.R as tidy as possible, that's why I prefer to send most of the tasks to other scripts.

[HenrikBengtsson]

Hi. That approach should work. Two things though, you want to do something like:

f <- future(source("script.R", local = TRUE)$value)

The reason for this is that source() returns the value via withVisible(), e.g.

script <- tempfile()
cat("x <- 42\nx\n", file = script)

res <- source(script, local = TRUE)
res
#> $value
#> [1] 42
#> 
#> $visible
#> [1] TRUE

value <- source(script, local = TRUE)$value
value
#> [1] 42

[iferres]

Great, thanks a lot @HenrikBengtsson !!

[iferres]

I'm not sure if it is worth the effort, but I can imagine using a future_source() function ;) I have no idea of the implications and usefulness of that, tho.