Define own \rowfont (without using tabu)

Question

Since the future of tabu is not that safe I’m trying to define an own \rowfont macro. This is what I’ve got so far:

\documentclass{article}

\usepackage{array,tabularx}
\usepackage[table]{xcolor}
\usepackage{xparse,etoolbox}

\ExplSyntaxOn\makeatletter

\int_new:N \l_@@_last_rownum_int

\cs_new_nopar:Npn \@@_current_rowfont: { }

\NewDocumentCommand { \rowfont } { m } {
   \cs_gset_nopar:Npn \@@_current_rowfont: { #1 }
   #1
}

\newcolumntype { L } {
   >{
      \int_compare:nNnTF { \int_use:N \l_@@_last_rownum_int } = { \number \rownum } {
         \@@_current_rowfont:
      } {
         \cs_gset_nopar:Npn \@@_current_rowfont: { }
         \@@_current_rowfont:
      }
   }
   l
   <{
      \int_gset:Nn \l_@@_last_rownum_int { \number \rownum }
   }
}
\newcolumntype { x } {
   >{
      \int_compare:nNnTF { \int_use:N \l_@@_last_rownum_int } = { \number \rownum } {
         \@@_current_rowfont:
      } {
         \cs_gset_nopar:Npn \@@_current_rowfont: { }
         \@@_current_rowfont:
      }
   }
   X
   <{
      \int_gset:Nn \l_@@_last_rownum_int { \number \rownum }
   }
}

\rowcolors { 0 } { } { }

\ExplSyntaxOff\makeatother

\begin{document}
tabular:
\begin{tabular}{LLL}
   \rowcolor{black}\rowfont{\color{red}}
   1 & 2 & 3 \\
   1 & 2 & 3 \\
\end{tabular}

\bigskip

tabularx:
\begin{tabularx}{0.5\textwidth}{xxx}
   \rowcolor{black}\rowfont{\sffamily\footnotesize\color{red}}
   1 & 2 & 3 \\
   1 & 2 & 3 \\
\end{tabularx}
\end{document}

Problems

• In {tabularx} the row using \rowfont gets enlarged when the argument of \rowfont contains \color.
• It only works when using \rowcolors.
• It can be used with special column types only.

Maybe it is possible to solve the problems with another definition …

Answer 1

An an alternative to tabu package, tabularray package provides a easy way to set row fonts and colors:

\documentclass{article}
\usepackage{tabularray}
\usepackage{xcolor}
\begin{document}
\begin{tblr}{
   width = 0.5\textwidth, colspec = {X[1]X[2]X[3]}, hlines,
   row{1} = {bg=gray9, fg=red3, font=\sffamily\footnotesize},
}
   1 & 2 & 3 \\
   1 & 2 & 3 \\
\end{tblr}
\end{document}