xindy: formatting the first letter of the first entry of a letter group

Question

How do I format the first letter of the first entry of a letter group in an index generated with xindy? The result should look something like this:

...
\indexspace

\item \textbf{b}athroom\quad{}1
\item beginner\quad{}9
\item boldface\quad{}2
...

Answer 1

There probably is a better solution than the present hack; however, the standard setting of xindy writes in front of each group something like

\lettergroup{A}

it's sufficient to say

\long\def\lettergroup#1\item{\item\textbf}
\let\lettergroupDefault\lettergroup

in the preamble. A letter group will be something like

\lettergroup{A}
\item abc

and the macro ignores everything up to the first item changing it into \item\textbf, so LaTeX will see

\item\textbf abc

and all will be right, as \textbf is a macro with one argument. For more complicated cases such as accented letters, this might be insufficient, though.