Greek text suppresses roman numbers?

Question

I am using the class memoir and I am writing a text in both French and Greek (only some words in Greek). I found some snippets online and managed to have something working with the command \textgreek{...}. The problem is that now I don't have Roman numbers in the table of contents for the different parts that compose my book. Here is a MWE that demonstrates the problem.

\documentclass[10pt]{memoir}

\usepackage{lipsum}
\usepackage{graphicx}
\usepackage[utf8]{inputenc}
\usepackage{polyglossia}
\usepackage{hyperref}

\setstocksize{190mm}{130mm}
\settrimmedsize{190mm}{130mm}{*}
\setlrmarginsandblock{20mm}{15mm}{*}
\setulmarginsandblock{20mm}{20mm}{*}
\checkandfixthelayout

\pretitle{\begin{center}\Huge\bfseries}
\title{Title}
\posttitle{\par\vskip1em{\normalfont\LARGE\scshape L'évolution\par\vfill}\end{center}}
\author{Name FamilyName}
\predate{\vfill\begin{center}\large}
\date{22 juin 2017}

% simple headers: only page number
\pagestyle{simple}

\setmainlanguage{french}
\setotherlanguage{greek}

\newfontfamily{\greekfont}{GFSDidot}[
  Extension=.otf,
  UprightFont=*,
  ItalicFont=*Italic,
  BoldFont=*Bold,
  BoldItalicFont=*BoldItalic,
  Scale=MatchLowercase,
]

\linespread{1.2}

\makeatletter
\@addtoreset{chapter}{part}
\makeatother



\begin{document}

\frontmatter
\begin{titlingpage}
\maketitle
\end{titlingpage}

\tableofcontents

\cleardoublepage
\chapter{Introduction}
\lipsum[1-3]

\mainmatter
\part{blah}
\chapter{blah blah}
Something in Greek: \textgreek{αττικόν}

\lipsum[1-3]

\chapter{blah}
\lipsum[1-3]



\part{blah}
\chapter{qwerty}
\lipsum[1-3]

\chapter{azerty}
\lipsum[1-3]

\end{document}

How can I solve this problem?

Answer 1

The culprit is \setmainlanguage{french} or better, the french language definition file of polyglossia, i.e. gloss-french.ldf, which has the macro

\def\captionsfrench{%
   \def\refname{Références}%
   \def\abstractname{Résumé}%
   \def\bibname{Bibliographie}%
   \def\prefacename{Préface}%
   \def\chaptername{Chapitre}%
   \def\appendixname{Annexe}%
   \def\contentsname{Table des matières}%
   \def\listfigurename{Table des figures}%
   \def\listtablename{Liste des tableaux}%
   \def\indexname{Index}%
   \def\figurename{\textsc{Fig.}}%
   \def\tablename{\textsc{Tab.}}%
   \def\@Fpt{\ifcase\value{part}\or Première\or Deuxième\or
   Troisième\or Quatrième\or Cinquième\or Sixième\or
   Septième\or Huitième\or Neuvième\or Dixième\or Onzième\or
   Douzième\or Treizième\or Quatorzième\or Quinzième\or
   Seizième\or Dix-septième\or Dix-huitième\or Dix-neuvième\or
   Vingtième\fi\space}%
   \def\thepart{}%%%%%%%%%%%%%%%%%
   \def\partname{\protect\@Fpt partie}%
   \def\pagename{page}%
   \def\seename{\emph{voir}}%
   \def\alsoname{\emph{voir aussi}}%
   \def\enclname{P.~J. }%
   \def\ccname{Copie à }%
   \def\headtoname{}%
   \def\proofname{Démonstration}%
   }

in which \thepart is defined to be empty, i.e. the usual definition of \Roman{part} or \@Roman \c@part is not used any longer.

This can be by-passed by saying

 \AtBeginDocument{%
  \renewcommand{\thepart}{\Roman{part}}
 }

or

\makeatletter
\AtBeginDocument{%
  \renewcommand{\thepart}{\@Roman\c@part}
}
\makeatother

after \setmainlanguage{french}

in order to allow the redefinition to take place after polyglossia settings.

\documentclass[10pt]{memoir}

\usepackage{lipsum}
\usepackage{graphicx}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage{polyglossia}

\setstocksize{190mm}{130mm}
\settrimmedsize{190mm}{130mm}{*}
\setlrmarginsandblock{20mm}{15mm}{*}
\setulmarginsandblock{20mm}{20mm}{*}
\checkandfixthelayout

\pretitle{\begin{center}\Huge\bfseries}
\title{Title}
\posttitle{\par\vskip1em{\normalfont\LARGE\scshape L'évolution\par\vfill}\end{center}}
\author{Name FamilyName}
\predate{\vfill\begin{center}\large}
\date{22 juin 2017}

% simple headers: only page number
\pagestyle{simple}

\setmainlanguage{french}
\setotherlanguage{greek}

\newfontfamily{\greekfont}{GFSDidot}[
  Extension=.otf,
  UprightFont=*,
  ItalicFont=*Italic,
  BoldFont=*Bold,
  BoldItalicFont=*BoldItalic,
  Scale=MatchLowercase,
]

\linespread{1.2}

\makeatletter
\@addtoreset{chapter}{part}
\AtBeginDocument{%
 \renewcommand{\thepart}{\@Roman\c@part}
}

\makeatother


\begin{document}
\frontmatter
\begin{titlingpage}
\maketitle
\end{titlingpage}

\tableofcontents

\cleardoublepage
\chapter{Introduction}
\lipsum[1-3]

\mainmatter
\part{blah}
\chapter{blah blah}
Something in Greek: \textgreek{αττικόν}

\lipsum[1-3]

\chapter{blah}
\lipsum[1-3]



\part{blah}
\chapter{qwerty}
\lipsum[1-3]

\chapter{azerty}
\lipsum[1-3]

\end{document}

Answer 2

You should remove \def\thepart{} from \captionsfrench and redefine \printpartnum in order to print nothing and removing the space before the (no longer printed) number.

\documentclass[10pt]{memoir}

\usepackage{lipsum}

\usepackage{polyglossia}
\usepackage{hyperref}

\setstocksize{190mm}{130mm}
\settrimmedsize{190mm}{130mm}{*}
\setlrmarginsandblock{20mm}{15mm}{*}
\setulmarginsandblock{20mm}{20mm}{*}
\checkandfixthelayout

\pretitle{\begin{center}\Huge\bfseries}
\title{Title}
\posttitle{\par\vskip1em{\normalfont\LARGE\scshape L'évolution\par\vfill}\end{center}}
\author{Name FamilyName}
\predate{\vfill\begin{center}\large}
\date{22 juin 2017}

% simple headers: only page number
\pagestyle{simple}

\setmainlanguage{french}
\setotherlanguage{greek}

\newfontfamily{\greekfont}{GFSDidot}[
  Extension=.otf,
  UprightFont=*,
  ItalicFont=*Italic,
  BoldFont=*Bold,
  BoldItalicFont=*BoldItalic,
  Scale=MatchLowercase,
]

\setSpacing{1.2}

\counterwithin{chapter}{part}

% fix the French setup of \def\thepart{}
\patchcmd{\captionsfrench}{\def\thepart{}}{}{}{}
\renewcommand{\printpartnum}{\unskip}

\begin{document}


\frontmatter
\begin{titlingpage}
\maketitle
\end{titlingpage}

\tableofcontents

\cleardoublepage
\chapter{Introduction}
\lipsum[1-3]

\mainmatter

\part{blah}
\chapter{blah blah}
Something in Greek: \textgreek{αττικόν}

\lipsum[1-3]

\chapter{blah}
\lipsum[1-3]



\part{blah}
\chapter{qwerty}
\lipsum[1-3]

\chapter{azerty}
\lipsum[1-3]

\end{document}

I fixed \linespread into the proper memoir command \setSpacing and also \@addtoreset into \counterwithin. If you don't want the Roman number before the chapter number, use

\counterwithin*{chapter}{part}

If you want “Partie I”, instead of \renewcommand{\printpartnum}{\unskip} do

\makeatletter
\patchcmd{\captionsfrench}
  {\def\partname{\protect\@Fpt partie}}
  {\def\partname{Partie}}
  {}{}
\makeatother