Como especificar a lacuna entre as entradas do índice

Question

O código

\documentclass{book}
\usepackage{imakeidx}
\let\cleardoublepage\clearpage
\makeindex
\usepackage[itemlayout=singlepar]{idxlayout}

\begin{document}
\LARGE

This is the first paragraph.\index{AA! first}\index{AA! second}\index{AA! third}

This is the second paragraph.\index{AAB! an entry}

This is the third paragraph.\index{AAC! another entry}

\idxlayout{columns=1}
\printindex
\end{document}

produz o índice:

Como posso especificar antecipadamente a lacuna (digamos, 5 pontos, 10 pontos, 12 pontos, etc.) entre AA e AAB; entre AAB e AAC?

Answer 1

Redefina \@idxitempara adicionar algum espaço vertical.

\documentclass{book}
\usepackage{imakeidx}
\usepackage[itemlayout=singlepar]{idxlayout}

\makeindex

\makeatletter
\renewcommand{\@idxitem}{\par\addvspace{\medskipamount}\hangindent40\p@}
\makeatother

\begin{document}

This is the first paragraph.\index{AA! first}\index{AA! second}\index{AA! third}

This is the second paragraph.\index{AAB! an entry}

This is the third paragraph.\index{AAC! another entry}

\idxlayout{columns=1}

\printindex

\end{document}