Makeidx, Subentries and dashes

Question

The following is the type of code I made.

\documentclass{article}
\usepackage{makeidx}
\makeindex
\begin{document}

... something\index{Lois!Lane} ...

\printindex
\end{document}

I'd like an index with a dash before any subentry (obviously, under the respectively entry)

Marco, Ill, 1
Lois,
 -  Lane, 1 
 -  John, 1

How can I do anything like this? What if a want with a comma after every dash? Like this

Marco, Ill, 1
Lois,
 -  , Lane, 1 
 -  , John, 1

EDIT

If it is not possible to perfectly allign the dash with makeidx, what about Xindy?

Answer 1

This requires the makeindex style file to be changed/extended.

For example, a dashindex.ist can be defined to be

item_1  "\n \\subitem -- , "
item_x1 "\n \\subitem -- , "

saying, that the sub levels should be preceeded by a dash and a comma.

Calling flow:

pdflatex foo

makeindex -s dashindex.ist foo

pdflatex foo

\documentclass{article}
\usepackage{xcolor}
\usepackage{makeidx}
\makeindex
\begin{document}

... somethex\index{Lois!Lane} ...

\index{Gandalf!The Grey}
\index{Gandalf!Stormcrow}
\index{Gandalf!Mithrandir}%
\index{Lois!John}
\index{Lois!Clark}

\printindex


\end{document}

A direct manipulation of \subitem

This cures the indentation problem -- in this case, no special .ist file is needed. I've set the subitem indent to 5pt, but this could be changed to basically any length value.

\documentclass{article}
\usepackage{makeidx}
\newlength{\subitemindent}
\setlength{\subitemindent}{5pt}
\makeindex
\makeatletter
\renewcommand{\subitem}{\par\hangindent 40\p@ \hspace*{\subitemindent} -- , }
\makeatother
\begin{document}

... somethex\index{Lois!Lane} ...

\index{Gandalf!The Grey}
\index{Gandalf!Stormcrow}
\index{Gandalf!Mithrandir}%
\index{Lois!John}
\index{Lois!Clark}

\printindex

\end{document}