Problem of rowhead and the number of rows in longtblr.

[note286]

iIf rowhead is less than the number of rows in longtblr, an error will be appear. Is this a design or a bug? It is reasonable for me to design the format first and fill in the contents later. The current version cannot meet this requirement.

\documentclass{article}
\usepackage{tabularray}
\begin{document}
\begin{longtblr}{colspec={ll},rowhead=1}
AAA & BBB \\
% AAA & BBB \\
\end{longtblr}
\end{document}

In the above example, only one line will go wrong, but two lines won't.

[lvjr]

The rowcount counter comes in handy when tabularray is parsing the inner specifications:

\documentclass{article}
\usepackage{tabularray}
\begin{document}
\ExplSyntaxOn
\begin{longtblr}{colspec={ll},rowhead=\int_compare:nNnTF{\value{rowcount}}>{1}{1}{0}}
AAA & BBB \\
% AAA & BBB \\
\end{longtblr}
\ExplSyntaxOff
\end{document}

[note286]

It solved my question perfectly. Thank you very much.