tests/autoprint.R

In data.table: Extension of data.frame

require(data.table)
# Tests the suppression of := output
# Since this tests autoprinting at the console, it needs to use the .Rout.save mechanism in R CMD check
DT = data.table(a=1:2)                # Should print at console?
DT                                    # yes
DT[1]                                 # yes
DT[2,a:=3L]                           # no
DT                                    # yes
print(DT[2,a:=4L])                    # yes
print(DT)                             # yes
(function(){DT[2,a:=5L];NULL})()      # no
DT                                    # yes
{DT[2,a:=6L];invisible()}             # no
print(DT)                             # yes
(function(){print(DT[2,a:=7L]);print(DT);invisible()})()    # yes*2
{print(DT[2,a:=8L]);print(DT);invisible()}                  # yes*2
DT[1][,a:=9L]      # no (was too tricky to detect that DT[1] is a new object). Simple rule is that := always doesn't print
DT[2,a:=10L][1]    # yes (because eval depth is above trigger in the := here via nested `[.data.table` calls, iiuc).
DT[1,a:=10L][1,a:=10L]                # no
DT[,a:=as.integer(a)]                 # no
DT[1,a:=as.integer(a)]                # no
DT[1,a:=10L][]                        # yes. ...[] == oops, forgot print(...)

# Test that error in := doesn't suppress next valid print, bug #2376
assign("depthtrigger", 20L, data.table:::.global)   # try() adds 10 levels of depth. But we need try() otherwise this script would stop.
try(DT[,foo:=ColumnNameTypo])         # error: not found.
DT                                    # yes  (if we didn't change depthtrigger above this would print for depth reason and not test it)
DT                                    # yes