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Merged
mattdowle merged 2 commits into from
Jun 22, 2021
Merged

set and := no longer warn when LHS is empty #4339

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009859e
set for empty cols does not warn anymore, #4086
jangorecki Apr 2, 2020
1662137
Merge branch 'master' into set-0len
mattdowle Jun 22, 2021
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2 changes: 2 additions & 0 deletions NEWS.md
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Original file line number Diff line number Diff line change
Expand Up @@ -169,6 +169,8 @@

9. `?"."`, `?".."`, `?".("`, and `?".()"` now point to `?data.table`, [#4385](https://github.com/Rdatatable/data.table/issues/4385) [#4407](https://github.com/Rdatatable/data.table/issues/4407). To help users find the documentation for these convenience features available inside `DT[...]`. Recall that `.` is an alias for `list`, and `..var` tells `data.table` to look for `var` in the calling environment as opposed to a column of the table.

10. `DT[, lhs:=rhs]` and `set(DT, , lhs, rhs)` no longer raise a warning on zero length `lhs`, [#4086](https://github.com/Rdatatable/data.table/issues/4086). Thanks to Jan Gorecki for the suggestion and PR. For example, `DT[, grep("foo", names(dt)) := NULL]` no longer warns if there are no column names containing `"foo"`.


# data.table [v1.14.0](https://github.com/Rdatatable/data.table/milestone/23?closed=1) (21 Feb 2021)

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11 changes: 9 additions & 2 deletions inst/tests/tests.Rraw
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Expand Up @@ -5045,9 +5045,16 @@ if (test_bit64) {
error="Cannot coerce 'list' RHS to 'integer64' to match.*column 6 named 'f'")
}

# FR #343, when LHS evaluates to integer(0), provide warning and return dt, not an error.
# FR #343, when LHS evaluates to integer(0), provide warning and return dt, not an error... but then... #4086 set could allow empty input without warning
dt = data.table(a = 1:5, b1 = 1:5, b2 = 1:5)
test(1295, dt[, grep("c", names(dt)) := NULL], dt, warning="length(LHS)==0; no columns to delete or assign RHS to")
test(1295.1, dt[, grep("c", names(dt)) := NULL], dt)
test(1295.2, set(dt, NULL, character(), 1L), dt)
test(1295.3, set(dt, 1L, character(), 1L), dt)
op = options(datatable.verbose=TRUE)
test(1295.4, dt[, grep("c", names(dt)) := NULL], dt, output="length(LHS)==0; no columns to delete or assign RHS to")
test(1295.5, set(dt, NULL, character(), 1L), dt, output="length(LHS)==0; no columns to delete or assign RHS to")
test(1295.6, set(dt, 1L, character(), 1L), dt, output="length(LHS)==0; no columns to delete or assign RHS to")
options(op)

# Updating logical column in one-row DT (corruption of new R 3.1 internal globals for TRUE, FALSE and NA)
DT = data.table(a=1:6, b=c(TRUE,FALSE))
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2 changes: 1 addition & 1 deletion src/assign.c
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Expand Up @@ -352,7 +352,7 @@ SEXP assign(SEXP dt, SEXP rows, SEXP cols, SEXP newcolnames, SEXP values)
}
}
if (!length(cols)) {
warning(_("length(LHS)==0; no columns to delete or assign RHS to.")); // test 1295 covers
if (verbose) Rprintf(_("length(LHS)==0; no columns to delete or assign RHS to.")); // test 1295 covers
*_Last_updated = 0;
UNPROTECT(protecti);
return(dt);
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