authoryear.bbx with additions for https://github.com/plk/biblatex/issues/520

authoryear.bbx

\ProvidesFile{authoryear.bbx}
[\abx@bbxid]

\RequireBibliographyStyle{standard}

\DeclareBibliographyOption[boolean]{dashed}[true]{%
  \ifstrequal{#1}{true}
    {\ExecuteBibliographyOptions{pagetracker}%
     \renewbibmacro*{bbx:savehash}{\savefield{fullhash}{\bbx@lasthash}}}
    {\renewbibmacro*{bbx:savehash}{}}}

\DeclareBibliographyOption[boolean]{mergedate}[true]{%
  \ifcsdef{bbx@opt@mergedate@#1}
    {\csuse{bbx@opt@mergedate@#1}}
    {\PackageError{biblatex}
       {Invalid option 'mergedate=#1'}
       {Valid values are 'maximum', 'compact', 'basic', 'minimum',\MessageBreak
        'true' (=compact), and 'false'.}}}

\providebibmacro*{date+extrayear}{}

\def\bbx@opt@mergedate@true{\bbx@opt@mergedate@compact}

% merge date/issue with date label
\def\bbx@opt@mergedate@maximum{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[parens]{%
         \printfield{issue}%
         \setunit*{\addspace}%
         \iffieldsequal{year}{labelyear}
           {\printlabeldateextra}%
           {\ifdefstring\blx@dateformat@labeldate{edtf}
              {}
              {\datecircaprint}%
            \dateeraprintpre{labelyear}%
            \printfield{labelyear}%
            \printfield{extrayear}%
            \dateuncertainprint%
            \iffieldsequal{labeldateera}{labelenddateera}
              {}
              {\dateeraprint{labelyear}}%
            \ifdefstring\blx@dateformat@labeldate{edtf}
              {\datecircaprintedtf}
              {}%
            \iffieldundef{labelendyear}
              {}
              {\iffieldsequal{labelyear}{labelendyear}
                 {}
                 {\ifdefstring\blx@dateformat@labeldate{edtf}
                    {\slash}% strict EDTF
                    {\bibdaterangesep
                     \enddatecircaprint}%
                  \dateeraprintpre{labelendyear}%
                  \printfield{labelendyear}%
                  \enddateuncertainprint
                  \ifdefstring\blx@dateformat@labeldate{edtf}
                    {\enddatecircaprintedtf}
                    {}%
                  \dateeraprint{labelendyear}}}}}}}%
  \renewbibmacro*{date}{}%
  \renewbibmacro*{issue+date}{}}

  
            

% merge date with date label
\def\bbx@opt@mergedate@compact{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[parens]{%
         \iffieldsequal{year}{labelyear}
           {\printlabeldateextra}%
           {\ifdefstring\blx@dateformat@labeldate{edtf}
              {}
              {\datecircaprint}%
            \dateeraprintpre{labelyear}%
            \printfield{labelyear}%
            \printfield{extrayear}%
            \dateuncertainprint%
            \iffieldsequal{labeldateera}{labelenddateera}
              {}
              {\dateeraprint{labelyear}}%
            \ifdefstring\blx@dateformat@labeldate{edtf}
              {\datecircaprintedtf}
              {}%
            \iffieldundef{labelendyear}
              {}
              {\iffieldsequal{labelyear}{labelendyear}
                 {}
                 {\ifdefstring\blx@dateformat@labeldate{edtf}
                    {\slash}% strict EDTF
                    {\bibdaterangesep
                     \enddatecircaprint}%
                  \dateeraprintpre{labelendyear}%
                  \printfield{labelendyear}%
                  \enddateuncertainprint
                  \ifdefstring\blx@dateformat@labeldate{edtf}
                    {\enddatecircaprintedtf}
                    {}%
                  \dateeraprint{labelendyear}}}}}}}%
  \renewbibmacro*{date}{}%
  \renewbibmacro*{issue+date}{%
    \iffieldundef{issue}
      {}
      {\printtext[parens]{\printfield{issue}}}%
    \newunit}}

% merge year-only date with date label
\def\bbx@opt@mergedate@basic{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[parens]{%
         \ifdefstring\blx@dateformat@labeldate{edtf}
           {}
           {\datecircaprint}%
         \dateeraprintpre{labelyear}%
         \printfield{labelyear}%
         \printfield{extrayear}%
         \dateuncertainprint%
         \iffieldsequal{labeldateera}{labelenddateera}
           {}
           {\dateeraprint{labelyear}}%
         \ifdefstring\blx@dateformat@labeldate{edtf}
           {\datecircaprintedtf}
           {}%
         \iffieldundef{labelendyear}
           {}
           {\iffieldsequal{labelyear}{labelendyear}
              {}
              {\ifdefstring\blx@dateformat@labeldate{edtf}
                 {\slash}% strict EDTF
                 {\bibdaterangesep
                  \enddatecircaprint}%
               \dateeraprintpre{labelendyear}%
               \printfield{labelendyear}%
               \enddateuncertainprint
               \ifdefstring\blx@dateformat@labeldate{edtf}
                 {\enddatecircaprintedtf}
                 {}%
               \dateeraprint{labelendyear}}}}}}%
  \renewbibmacro*{date}{%
    \ifboolexpr{
      test {\iffieldundef{season}}
      and
      test {\iffieldundef{month}}
    }
      {}
      {\printdate}}%
  \renewbibmacro*{issue+date}{%
    \ifboolexpr{
      test {\iffieldundef{issue}}
      and
      test {\iffieldundef{season}}
      and
      test {\iffieldundef{month}}
    }
      {}
      {\printtext[parens]{%
         \printfield{issue}%
         \setunit*{\addspace}%
         \printdate}}%
    \newunit}}

% merge year-only date with year-only date label
\def\bbx@opt@mergedate@minimum{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[parens]{%
         \ifdefstring\blx@dateformat@labeldate{edtf}
           {}
           {\datecircaprint}%
         \dateeraprintpre{labelyear}%
         \printfield{labelyear}%
         \printfield{extrayear}%
         \dateuncertainprint%
         \iffieldsequal{labeldateera}{labelenddateera}
           {}
           {\dateeraprint{labelyear}}%
         \ifdefstring\blx@dateformat@labeldate{edtf}
           {\datecircaprintedtf}
           {}%
         \iffieldundef{labelendyear}
           {}
           {\iffieldsequal{labelyear}{labelendyear}
              {}
              {\ifdefstring\blx@dateformat@labeldate{edtf}
                 {\slash}% strict EDTF
                 {\bibdaterangesep
                  \enddatecircaprint}%
               \dateeraprintpre{labelendyear}%
               \printfield{labelendyear}%
               \enddateuncertainprint
               \ifdefstring\blx@dateformat@labeldate{edtf}
                 {\enddatecircaprintedtf}
                 {}%
               \dateeraprint{labelendyear}}}}}}%
  \renewbibmacro*{date}{%
    \ifboolexpr{
      test {\iffieldundef{season}}
      and
      test {\iffieldundef{month}}
      and
      test {\iffieldundef{extrayear}}
    }
      {}
      {\printdate}}%
  \renewbibmacro*{issue+date}{%
    \ifboolexpr{
      test {\iffieldundef{issue}}
      and
      test {\iffieldundef{season}}
      and
      test {\iffieldundef{month}}
      and
      test {\iffieldundef{extrayear}}
    }
      {}
      {\printtext[parens]{%
         \printfield{issue}%
         \setunit*{\addspace}%
         \printdate}}%
    \newunit}}

% don't merge date/issue with date label
\def\bbx@opt@mergedate@false{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[parens]{%
         \ifdefstring\blx@dateformat@labeldate{edtf}
           {}
           {\datecircaprint}%
         \dateeraprintpre{labelyear}%
         \printfield{labelyear}%
         \printfield{extrayear}%
         \dateuncertainprint%
         \iffieldsequal{labeldateera}{labelenddateera}
           {}
           {\dateeraprint{labelyear}}%
         \ifdefstring\blx@dateformat@labeldate{edtf}
           {\datecircaprintedtf}
           {}%
         \iffieldundef{labelendyear}
           {}
           {\iffieldsequal{labelyear}{labelendyear}
              {}
              {\ifdefstring\blx@dateformat@labeldate{edtf}
                 {\slash}% strict EDTF
                 {\bibdaterangesep
                  \enddatecircaprint}%
               \dateeraprintpre{labelendyear}%
               \printfield{labelendyear}%
               \enddateuncertainprint
               \ifdefstring\blx@dateformat@labeldate{edtf}
                 {\enddatecircaprintedtf}
                 {}%
               \dateeraprint{labelendyear}}}}}}%
  \renewbibmacro*{date}{\printdate}%
  \renewbibmacro*{issue+date}{%
    \printtext[parens]{%
      \printfield{issue}%
      \setunit*{\addspace}%
      \printdate}%
    \newunit}}

% n.b. the default labeldate=year overrides merging of months and days
\ExecuteBibliographyOptions{labeldateparts,sorting=nyt,pagetracker,mergedate}

\DeclareFieldFormat{shorthandwidth}{#1}
\setlength{\bibitemsep}{0pt}

\DeclareNameAlias{author}{sortname}
\DeclareNameAlias{editor}{sortname}
\DeclareNameAlias{translator}{sortname}

\defbibenvironment{bibliography}
  {\list
     {}
     {\setlength{\leftmargin}{\bibhang}%
      \setlength{\itemindent}{-\leftmargin}%
      \setlength{\itemsep}{\bibitemsep}%
      \setlength{\parsep}{\bibparsep}}}
  {\endlist}
  {\item}

\defbibenvironment{shorthand}
  {\list
     {\printfield[shorthandwidth]{shorthand}}
     {\setlength{\labelwidth}{\shorthandwidth}%
      \setlength{\leftmargin}{\labelwidth}%
      \setlength{\labelsep}{\biblabelsep}%
      \addtolength{\leftmargin}{\labelsep}%
      \setlength{\itemsep}{\bibitemsep}%
      \setlength{\parsep}{\bibparsep}%
      \renewcommand*{\makelabel}[1]{##1\hss}}}
  {\endlist}
  {\item}

\InitializeBibliographyStyle{\global\undef\bbx@lasthash}

\newbibmacro*{bbx:savehash}{%
  \savefield{fullhash}{\bbx@lasthash}}

\newbool{bbx@inset}
\DeclareBibliographyDriver{set}{%
  \booltrue{bbx@inset}%
  \entryset{}{}%
  \newunit\newblock
  \usebibmacro{setpageref}%
  \finentry}

\renewbibmacro*{begrelated}{%
  \booltrue{bbx@inset}}

\renewbibmacro*{endrelated}{%
  \usebibmacro*{bbx:savehash}}

\renewbibmacro*{author}{%
  \ifboolexpr{
    test \ifuseauthor
    and
    not test {\ifnameundef{author}}
  }
    {\usebibmacro{bbx:dashcheck}
       {\bibnamedash}
       {\usebibmacro{bbx:savehash}%
        \printnames{author}%
        \iffieldundef{authortype}
          {\setunit{\printdelim{nameyeardelim}}}
          {\setunit{\addcomma\space}}}%
     \iffieldundef{authortype}
       {}
       {\usebibmacro{authorstrg}%
        \setunit{\printdelim{nameyeardelim}}}}%
    {\global\undef\bbx@lasthash
     \usebibmacro{labeltitle}%
     \setunit*{\printdelim{nonameyeardelim}}}%
  \usebibmacro{date+extrayear}}

\renewbibmacro*{editor}{%
  \usebibmacro{bbx:editor}{editorstrg}}
\renewbibmacro*{editor+others}{%
  \usebibmacro{bbx:editor}{editor+othersstrg}}
\newbibmacro*{bbx:editor}[1]{%
  \ifboolexpr{
    test \ifuseeditor
    and
    not test {\ifnameundef{editor}}
  }
    {\usebibmacro{bbx:dashcheck}
       {\bibnamedash}
       {\printnames{editor}%
        \setunit{\addcomma\space}%
        \usebibmacro{bbx:savehash}}%
     \usebibmacro{#1}%
     \clearname{editor}%
     \setunit{\printdelim{nameyeardelim}}}%
    {\global\undef\bbx@lasthash
     \usebibmacro{labeltitle}%
     \setunit*{\printdelim{nonameyeardelim}}}%
  \usebibmacro{date+extrayear}}

\renewbibmacro*{translator}{%
  \usebibmacro{bbx:translator}{translatorstrg}}
\renewbibmacro*{translator+others}{%
  \usebibmacro{bbx:translator}{translator+othersstrg}}
\newbibmacro*{bbx:translator}[1]{%
  \ifboolexpr{
    test \ifusetranslator
    and
    not test {\ifnameundef{translator}}
  }
    {\usebibmacro{bbx:dashcheck}
       {\bibnamedash}
       {\printnames{translator}%
        \setunit{\addcomma\space}%
        \usebibmacro{bbx:savehash}}%
     \usebibmacro{translator+othersstrg}%
     \clearname{translator}%
     \setunit{\printdelim{nameyeardelim}}}%
    {\global\undef\bbx@lasthash
     \usebibmacro{labeltitle}%
     \setunit*{\printdelim{nonameyeardelim}}}%
  \usebibmacro{date+extrayear}}

\newbibmacro*{bbx:dashcheck}[2]{%
  \ifboolexpr{
    test {\iffieldequals{fullhash}{\bbx@lasthash}}
    and
    not test \iffirstonpage
    and
    (
       not bool {bbx@inset}
       or
       test {\iffieldequalstr{entrysetcount}{1}}
    )
  }
    {#1}
    {#2}}

\newbibmacro*{labeltitle}{%
  \iffieldundef{label}
    {\iffieldundef{shorttitle}
       {\printfield{title}%
        \clearfield{title}}
       {\printfield[title]{shorttitle}}}
    {\printfield{label}}}

\endinput