fixup: format_tt j cannot be NULL

R/format_tt.R

@@ -131,6 +131,11 @@ format_tt_lazy <- function(x,
   assert_flag(markdown)
   j <- sanitize_j(j, x)
 
+  # In sanity_tt(), we fill in missing NULL `j` in the format-specific versions,
+  # because tabularray can do whole column styling. Here, we need to fill in
+  # NULL for all formats since this is applied before creating the table.
+  if (is.null(j)) j <- seq_len(ncol(x))
+
   # format each column
   for (col in j) {
     # sprintf() is self-contained

vignettes/tutorial.qmd

@@ -465,12 +465,20 @@ We can style entire columns by omitting the `i` argument:
 tt(x) |> style_tt(j = c(2, 4), bold = TRUE)
 ```
 
-The `j` argument accepts integer vectors, but also a string with a Perl-style regular expression, which makes it easier to select columns by name:
+The `j` argument accepts integer vectors, character vectors, but also a string with a Perl-style regular expression, which makes it easier to select columns by name:
 
 ```{r}
+tt(x) |> style_tt(j = c("mpg", "drat"), color = "orange")
+
 tt(x) |> style_tt(j = "mpg|drat", color = "orange")
 ```
 
+Here we use a "negative lookahead" to exclude certain columns:
+
+```{r}
+tt(x) |> style_tt(j = "^(?!drat|mpg)", color = "orange")
+```
+
 Of course, we can also call the `style_tt()` function several times to apply different styles to different parts of the table:
 
 ```{r}