`:=` not suppressing print in R 3.2.0

[jangorecki]

Worth to note that test.data.table passed successfully.

library(data.table)
# data.table 1.9.5  For help type: ?data.table
# *** NB: by=.EACHI is now explicit. See README to restore previous behaviour.
DT <- data.table(a=1L)
DT[, a:=2L]
#    a
#1: 2
sessionInfo()
# R version 3.2.0 (2015-04-16)
# Platform: x86_64-pc-linux-gnu (64-bit)
# Running under: Ubuntu 14.04.2 LTS
# 
# locale:
#  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
#  [3] LC_TIME=en_DK.UTF-8        LC_COLLATE=en_US.UTF-8    
#  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=C             
#  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
#  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
# [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
# 
# attached base packages:
# [1] stats     graphics  grDevices utils     datasets  methods   base     
# 
# other attached packages:
# [1] data.table_1.9.5
# 
# loaded via a namespace (and not attached):
# [1] chron_2.3-45

[shrektan]

I encounter the same problem .
Here is my sessioninfo:

R version 3.2.0 (2015-04-16)
Platform: i386-w64-mingw32/i386 (32-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

locale:
[1] LC_COLLATE=Chinese (Simplified)_People's Republic of China.936 
[2] LC_CTYPE=Chinese (Simplified)_People's Republic of China.936   
[3] LC_MONETARY=Chinese (Simplified)_People's Republic of China.936
[4] LC_NUMERIC=C                                                   
[5] LC_TIME=Chinese (Simplified)_People's Republic of China.936    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] data.table_1.9.5

loaded via a namespace (and not attached):
[1] tools_3.2.0  chron_2.3-45

[jangorecki]

I found this not a big deal as data.table print nicely. If the current suppress print is costly in maintenance maybe it should be dropped at all?
Maybe a special [ call to explicitly make results invisibility would be less costly in terms of dev and maintenance?
Example where i = ! suppress output:

dt[ any stuff ][!]

[shrektan]

@arunsrinivasan
I use data.table a lot in my work~ This package is really really good and I love it so much.
It would be better, if this can be solved, so I can stop to write things like `invisible(DT[, x:=1])'.
Anything I can do to help?
Thanks.

[arunsrinivasan]

@shrektan, thank you :-). On this issue, I think @mattdowle would've much better idea.

[abielr]

On a related point, the programmers of the IRKernel package for Jupyter are having trouble determining if := should suppress output. See https://github.com/IRkernel/IRkernel/issues/127. Note that this is with R < 3.2.0.

[abielr]

Changing

typeof(last(SYS)[[2L]]) %chin% c("list","promise"))

to

typeof(last(SYS)[[2L]]) %chin% c("list","promise","symbol"))

in the R/data.table.R/print.data.table() function seems to fix the issue (tested on R 3.2.0 on OSX), however I'm really not sure what is going on with these calls so I don't have a good sense of whether this would also cause unintended behavior elsewhere.

[arunsrinivasan]

@abielr thanks for a possible solution. Have added to 1.9.6. I think it'd be nice to have this fixed for next release.

[MichaelChirico]

:= within a function is back to printing out for me, e.g.:

dt<-data.table(a=c(1,2,3))
f<-function(nm){dt[,(nm):=1]}
> f("b")
   a b
1: 1 1
2: 2 1
3: 3 1

Relevant sessionInfo() bits:

R version 3.2.1 (2015-06-18)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 14.04.2 LTS
...
data.table_1.9.5 #(updated this morning)

Was there another update I'm missing?

[MaxGhenis]

I believe := printing within a function is a separate issue, which has existed in the past. Would be great to fix that as well, but may make sense to file separately.

[arunsrinivasan]

Update to R 3.2.2 and try again.