How to make a custom list of symbols with separated greek and roman symbols?

Question

I am using the glossaries package to make a list of acronyms and a list of symbols (separately). Following this approach, I tried to make a list of symbols that has that layout, but with a separated greek and roman symbols section.

I tried to do this using the link's \newglossarystyle command:

\newglossarystyle{symbunitlong}{%
  \setglossarystyle{long4col-booktabs}%
  \renewenvironment{theglossary}%
    {%
     \renewcommand{\arraystretch}{1.5}%
     \begin{longtable}{cp{\glsdescwidth}c>{\centering}p{\glspagelistwidth}}}%
    {\end{longtable}}%
  \renewcommand*{\glossaryheader}{%
    \bfseries Symbol & \bfseries \descriptionname & \bfseries Unit & \bfseries First appearance \tabularnewline
    \midrule\endhead}%
    \renewcommand{\glossentry}[2]{\glsentryitem{##1}\glstarget{##1}{\glossentryname{##1}} & \glossentrydesc{##1}  & \glossentrydesc{##1} & \glsentryunit{##1} 
        \tabularnewline
    }%
}

This gives me a push in the right direction in that the separation of roman and greek letters is correct. However, the units column and symbols column, except for the Roman letters and Greek letters indicators, are left entirely empty.

Taken from this question, I have defined the unit key using this command, before calling \makeglossaries:

\glsaddkey
{unit}          % new key
{\relax}        % default value if "unit" isn't used in \newglossaryentry
{\glsentryunit} % analogous to \glsentrytext
{\Glsentryunit} % analogous to \Glsentrytext
{\glsunit}      % analogous to \glstext
{\Glsunit}      % analogous to \Glstext
{\GLSunit}      % analogous to \GLStext

I have made the distinction between Roman and Greek symbols by assigning a parent to each glossary entry, following this approach:

% Define the parent romand and greek symbols
\newglossaryentry{romanletter}{name={\textbf{Roman letters}}, description={\nopostdesc}, sort={1}, type=symbols}
\newglossaryentry{greekletter}{name={\textbf{Greek letters}}, description={\nopostdesc}, sort={2}, type=symbols}

% Don't expand the unit field 
\glssetnoexpandfield{unit}

% Some sample symbol glossary entries
\newglossaryentry{drag}{name={\ensuremath{D}},
                     sort={drag},
                     description={drag},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\newton}}}
\newglossaryentry{h}{name={\ensuremath{h}},
                     sort={h},
                     description={altitude},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\metre}}}
\newglossaryentry{lift}{name={\ensuremath{L}},
                     sort={lift},
                     description={lift},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\newton}}}
\newglossaryentry{mach}{name={\ensuremath{M}},
                     sort={Mach number},
                     description={Mach number},
                     parent={romanletter},
                     type={symbols},
                     unit={[-]}}
\newglossaryentry{mass}{name={\ensuremath{m}},
                     sort={mass},
                     description={mass},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\kilogram}}}
\newglossaryentry{pitchrate}{name={\ensuremath{q}},
                     sort={q},
                     description={pitch rate},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\radian\per\second}}}
% Some greek letter
\newglossaryentry{eta}{name={\ensuremath{\eta}},
                        sort={7},
                        description={(propulsive) efficiency},
                        parent={greekletter}, 
                        type={symbols},
                        unit={[-]}}

I am probably going wrong somewhere in the \newglossarystyle command, but I've been trying to work it out reading the docs and inspecting previously posted questions, but I can't seem to work it out. I find the syntax \renewcommand{\glossentry}[2]{\glsentryitem{##1}\glstarget{##1}{\glossentryname{##1}} & \glossentrydesc{##1} & \glossentrydesc{##1} & \glsentryunit{##1} quite confusing and am not able to work out all those commands from the glossaries docs.

Summarising all the above in a MWE:

\documentclass{report}
\usepackage{siunitx} \sisetup{detect-all}
\usepackage{hyperref}
\usepackage[nopostdot, toc, nogroupskip, nomain, indexonlyfirst, acronym, symbols, style=long4col, stylemods={longbooktabs}]{glossaries-extra}
\GlsXtrEnablePreLocationTag{page~}{pages~}

\glsaddkey
{unit}          % new key
{\relax}        % default value if "unit" isn't used in \newglossaryentry
{\glsentryunit} % analogous to \glsentrytext
{\Glsentryunit} % analogous to \Glsentrytext
{\glsunit}      % analogous to \glstext
{\Glsunit}      % analogous to \Glstext
{\GLSunit}      % analogous to \GLStext

\makeglossaries

% Define the parent romand and greek symbols
\newglossaryentry{romanletter}{name={\textbf{Roman letters}}, description={\nopostdesc}, sort={1}, type=symbols}
\newglossaryentry{greekletter}{name={\textbf{Greek letters}}, description={\nopostdesc}, sort={2}, type=symbols}

% Don't expand the unit field 
\glssetnoexpandfield{unit}

% Some sample symbol glossary entries
\newglossaryentry{drag}{name={\ensuremath{D}},
                     sort={drag},
                     description={drag},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\newton}}}
\newglossaryentry{h}{name={\ensuremath{h}},
                     sort={h},
                     description={altitude},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\metre}}}
\newglossaryentry{lift}{name={\ensuremath{L}},
                     sort={lift},
                     description={lift},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\newton}}}
\newglossaryentry{mach}{name={\ensuremath{M}},
                     sort={Mach number},
                     description={Mach number},
                     parent={romanletter},
                     type={symbols},
                     unit={[-]}}
\newglossaryentry{mass}{name={\ensuremath{m}},
                     sort={mass},
                     description={mass},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\kilogram}}}
\newglossaryentry{pitchrate}{name={\ensuremath{q}},
                     sort={q},
                     description={pitch rate},
                     parent={romanletter},
                     type={symbols},
                     unit={\si{\radian\per\second}}}
% Some greek letter
\newglossaryentry{eta}{name={\ensuremath{\eta}},
                        sort={7},
                        description={(propulsive) efficiency},
                        parent={greekletter}, 
                        type={symbols},
                        unit={[-]}}

% Set the new glossary style
\newglossarystyle{symbunitlong}{%
  \setglossarystyle{long4col-booktabs}%
  \renewenvironment{theglossary}%
    {%
     \renewcommand{\arraystretch}{1.5}%
     \begin{longtable}{cp{\glsdescwidth}c>{\centering}p{\glspagelistwidth}}}%
    {\end{longtable}}%
  \renewcommand*{\glossaryheader}{%
    \bfseries Symbol & \bfseries \descriptionname & \bfseries Unit & \bfseries First appearance \tabularnewline
    \midrule\endhead}%
    \renewcommand{\glossentry}[2]{\glsentryitem{##1}\glstarget{##1}{\glossentryname{##1}} & \glossentrydesc{##1}  & \glossentrydesc{##1} & \glsentryunit{##1} 
        \tabularnewline
    }%
}

\begin{document}

\glsaddall
\printglossary[type=symbols, style=symbunitlong]

\end{document}

Thanks in advance!

P.S. I would also like each column's width to be adapted to the widest entry in that column. For example, the last column should be made wider to display First appearance in one line. Moreover, the entries should be left-aligned instead of centered. This is of secondary importance, though.

Answer 1

Okaaaay ... i'm no expert in glossary styles, so i tried my best.

First of all your biggest mistake was not to use the full possibilities of the glossaries-extra package ^_~ See this link for more, but take your awe & time because you will need it. That aside, there you will find the longextra stylemod as well as the long-loc-sym-desc-name style. It is a perfect start for your style choice.

By defining a symbol using the symbol key you have everything you need for the style modification. I copied most of it from the original style file (after package installation: MiKTeX->tex->latex->glossaries-extra). Last but not least define your column order and of course the use of the unit key.

\documentclass{report}
\usepackage{blindtext}
\usepackage{siunitx}    \sisetup{detect-all}
\usepackage{hyperref}
\usepackage[nopostdot, toc, nogroupskip, nomain, indexonlyfirst, acronym, symbols, style=long4col, stylemods={longextra}]{glossaries-extra}
\GlsXtrEnablePreLocationTag{page~}{pages~}

\glsaddkey
{unit}          % new key
{\relax}        % default value if "unit" isn't used in \newglossaryentry
{\glsentryunit} % analogous to \glsentrytext
{\Glsentryunit} % analogous to \Glsentrytext
{\glsunit}      % analogous to \glstext
{\Glsunit}      % analogous to \Glstext
{\GLSunit}      % analogous to \GLStext

\makeglossaries

% Define the parent roman and greek symbols
\newglossaryentry{romanletter}{
    name={\textbf{Roman letters}},
    description={\nopostdesc}, 
    sort={1}, 
    type=symbols,
}
\newglossaryentry{greekletter}{
    name={\textbf{Greek letters}},
    description={\nopostdesc}, 
    sort={2}, 
    type=symbols,
}

% Don't expand the unit field 
\glssetnoexpandfield{unit}

% Some sample symbol glossary entry with roman letter ...
\newglossaryentry{mass}{
    name={mass},
    symbol={\ensuremath{m}},
    unit={\si{\kilogram}},
    description={mass},
    parent={romanletter},
    type={symbols},
    sort={mass},
}
% ... and also with some greek letter
\newglossaryentry{eta}{
    name={eta},
    symbol={\ensuremath{\eta}},
    unit={[-]},
    description={(propulsive) efficiency},
    parent={greekletter}, 
    type={symbols},
    sort={eta},
}

% Inform glossary about your own key (see manual v1.41, p.60 about its original definition)
\renewcommand{\glslongextraSubNameFmt}[2]{
    \glssubentryitem{#2}\glstarget{#2}{\glsentryunit{#2}\strut}
}
% Set the new glossary style
\newglossarystyle{long-sym-desc-unit-loc}{%
    \setglossarystyle{long-loc-sym-desc-name}%
    \renewenvironment{theglossary}%
    {%
    \glspatchLToutput
    \glslongextraSymLocSetDescWidth
    \edef\@glslongextra@begintab{%
        \noexpand\begin{longtable}{%
                \expandonce\glslongextraSymbolAlign
                \expandonce\glslongextraDescAlign
                \expandonce\glslongextraNameAlign
                \expandonce\glslongextraLocationAlign
        }}%
        \@glslongextra@begintab
    }%
    {\end{longtable}
    }%
    \renewcommand*{\glossaryheader}{%
        \bfseries Symbol%
        & \bfseries \descriptionname %
        & \bfseries Unit %
        & \bfseries \mbox{1st page}%
        \tabularnewline%
        \midrule%
        \endhead%
    }%
    \renewcommand*{\glsgroupheading}[1]{\glslongextraGroupHeading{4}{##1}}%
    \renewcommand{\glossentry}[2]{%
        \glslongextraNameFmt{##1} & & &%
        \tabularnewline
    }% 
    \renewcommand{\subglossentry}[3]{%
        \glslongextraSubSymbolFmt{##1}{##2} &
        \glslongextraSubDescFmt{##1}{##2} &
        \glslongextraSubNameFmt{##1}{##2} &
        \glslongextraSubLocationFmt{##1}{##2}{##3}%
        \tabularnewline
    }%
}

\begin{document}
\blindtext
\gls{eta} 

\Blindtext
\gls{mass}

\printglossary[type=symbols, style=long-sym-desc-unit-loc]
\end{document}