Skip to content

j auto-naming might delete an explicit NULL #4063

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
mattdowle merged 2 commits into from
Nov 20, 2019
Merged

j auto-naming might delete an explicit NULL #4063

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
01bb090
j auto-naming might delete an explicit NULL
Nov 19, 2019
f9c360e
news item; added 'i.e.' and referred very briefly to the issue Kun found
mattdowle Nov 20, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion NEWS.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@

## NEW FEATURES

1. `DT[, {...; .(A,B)}]` (when `.()` is the final item of a multi-statement `{...}`) now auto-names the columns `A` and `B` (just like `DT[, .(A,B)]`) rather than `V1` and `V2`, [#2478](https://github.com/Rdatatable/data.table/issues/2478) [#609](https://github.com/Rdatatable/data.table/issues/609). Similarly, `DT[, if (.N>1) .(B), by=A]` now auto-names the column `B` rather than `V1`. Explicit names are unaffected; e.g. `DT[, {... y= ...; .(A=C+y)}, by=...]` named the column `A` before, and still does.
1. `DT[, {...; .(A,B)}]` (i.e. when `.()` is the final item of a multi-statement `{...}`) now auto-names the columns `A` and `B` (just like `DT[, .(A,B)]`) rather than `V1` and `V2`, [#2478](https://github.com/Rdatatable/data.table/issues/2478) [#609](https://github.com/Rdatatable/data.table/issues/609). Similarly, `DT[, if (.N>1) .(B), by=A]` now auto-names the column `B` rather than `V1`. Explicit names are unaffected; e.g. `DT[, {... y= ...; .(A=C+y)}, by=...]` named the column `A` before, and still does. Thanks also to @renkun-ken for his go-first strong testing which caught an issue not caught by the test suite or by revdep testing, related to NULL being the last item, [#4061](https://github.com/Rdatatable/data.table/issues/4061).

## BUG FIXES

Expand Down
2 changes: 1 addition & 1 deletion R/data.table.R
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -886,7 +886,7 @@ replace_dot_alias = function(e) {
return(q) # else empty list is needed for test 468: adding an empty list column
}
if (q[[1L]] == '{') {
q[[length(q)]] = do_j_names(q[[length(q)]])
if (!is.null(q[[qlen<-length(q)]])) q[[qlen]] = do_j_names(q[[qlen]])
return(q)
}
if (q[[1L]] == 'if') {
Expand Down
2 changes: 2 additions & 0 deletions inst/tests/tests.Rraw
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16378,6 +16378,8 @@ test(2121.3, DT[ , if (.N > 1L) .(b), by=a], DT[1:2])
test(2121.4, DT[ , if (.N > 1L) .(b) else .(c=b), by=a], DT[ , .(a, c=b)],
warning="Different branches of j expression produced different auto-named columns")
test(2121.5, DT[, .(.N=.N), by=a], data.table(a=c(1,2), .N=2:1)) # user supplied names preside over autoname dropping leading dot
## { ending in NULL should retain that NULL, #4061
test(2121.6, DT[ , {.(a, b=b+1); NULL}], NULL)


###################################
Expand Down