%  environ.cd
%  Anders G S Svensson

%  Source: environ.nw
%          $Revision: 1.9 $
%          $Date: 1996/02/19 19:21:07 $

\def\B#1{\environ@envin@{#1}\@cs@{environ@benv@#1}}
\def\E#1{\@cs@{environ@eenv@#1}\environ@envout@{#1}}

\def\environ@B@#1{\environ@blockin@{#1}\@cs@{environ@bblo@#1}}
\def\environ@E@#1{\@cs@{environ@eblo@#1}\environ@blockout@{#1}}

\def\environ@envin@#1{\environ@checkin@{env}{#1}}
\def\environ@blockin@#1{\environ@checkin@{blo}{#1}}
\def\environ@envout@#1{\environ@checkout@{env}{#1}}
\def\environ@blockout@#1{\environ@checkout@{blo}{#1}}

\let\environ@checkin@\@eattwo@
\let\environ@checkout@\@eattwo@

\DeclareOption{check}
   {\def\environ@checkin@#1#2{\relax
       \@ifundefined@{environ@b#1@#2}{\environ@unknown@{#1}{#2}}{}%
       \gdef\environ@currenv@{{#1}{#2}}%
       \xdef\environ@envstack@{{#1}{#2}\environ@envstack@}}
    \def\environ@checkout@#1#2{\relax
        \@ifx@\environ@currenv@\environ@topenv@
           {\environ@toperror@{#1}{#2}}%
           {\@strcmp@{#2}{\expandafter\@SecondOfTwo@\environ@currenv@}
               {\@expandafter@{\expandafter\environ@popenv@\@eattwo@}\environ@envstack@ @}%
               {\environ@incompat@{#1}{#2}}
            \@ifundefined@{environ@e#1@#2}{\environ@unknown@{#1}{#2}}{}}}%
    \def\environ@topenv@{{}{}}
    \let\environ@currenv@\environ@topenv@
    \let\environ@envstack@\environ@topenv@
    \def\environ@toperror@#1#2{%
       \@Warning@{\environ@endstring@{#1}{#2} at top level}}
    \def\environ@incompat@#1#2{%
       \@Warning@{\expandafter\environ@beginstring@\environ@currenv@\@space@
                  terminated by \environ@endstring@{#1}{#2}}}
    \def\environ@unknown@#1#2{\@Warning@{Unknown \environ@environname@{#1}: #2}}
    \def\environ@beginstring@#1#2{\@cs@{environ@b#1string@}{#2}}
    \def\environ@endstring@#1#2{\@cs@{environ@e#1string@}{#2}}
    \def\environ@benvstring@#1{\string\B{#1}}
    \def\environ@eenvstring@#1{\string\E{#1}}
    \def\environ@bblostring@#1{\expandafter\string\csname #1\endcsname}
    \def\environ@eblostring@#1{\expandafter\string\csname end#1\endcsname}
    \def\environ@environname@#1{\@cs@{environ@#1name@}}
    \def\environ@envname@{environment}
    \def\environ@bloname@{block}
    \def\environ@popenv@#1#2#3@{%
       \gdef\environ@currenv@{{#1}{#2}}\gdef\environ@envstack@{#3}}}

\def\Bdef{\relax\environ@def@{def}{b}}
\def\Blet{\relax\environ@def@{let}{b}}
\def\Edef{\relax\environ@def@{def}{e}}
\def\Elet{\relax\environ@def@{let}{e}}

\def\environ@def@#1#2{%
  \@ifnextchar@*%
      {\@expandafter@{\environ@blodef@{#1}{#2}}\@eat@}%
      {\environ@envdef@{#1}{#2}}}

\def\environ@envdef@#1#2#3{%
   \@cs@{@#1@}{environ@#2env@#3}}

\def\environ@blodef@#1#2#3{%
   \@def@{#3}{\environ@B@{#3}}\@def@{end#3}{\environ@E@{#3}}\@cs@{@#1@}{environ@#2blo@#3}}

\def\newgroup{\relax
   \@ifnextchar@*{\expandafter\environ@newblockgroup@\@eat@}\environ@newenvgroup@}

\def\environ@newblockgroup@#1{%
   \@def@{#1}{\environ@B@{#1}}\@def@{end#1}{\environ@E@{#1}}%
   \environ@n@wblockgroup@{#1}}
\long\def\environ@n@wblockgroup@#1#2#3{%
   \@def@{environ@bblo@#1}{\begingroup#2}
   \@def@{environ@eblo@#1}{#3\endgroup}}

\def\environ@newenvgroup@#1{%
   \environ@n@wenvgroup@{#1}}
\long\def\environ@n@wenvgroup@#1#2#3{%
   \@def@{environ@benv@#1}{\begingroup#2}
   \@def@{environ@eenv@#1}{#3\endgroup}}

\def\newpair{\relax
   \@ifnextchar@*{\expandafter\environ@newblockpair@\@eat@}\environ@newenvpair@}

\def\environ@newblockpair@#1{%
   \@def@{#1}{\environ@B@{#1}}\@def@{end#1}{\environ@E@{#1}}%
   \environ@n@wblockpair@{#1}}
\long\def\environ@n@wblockpair@#1#2#3{%
   \@def@{environ@bblo@#1}{#2}
   \@def@{environ@eblo@#1}{#3}}

\def\environ@newenvpair@#1{%
   \environ@n@wenvpair@{#1}}
\long\def\environ@n@wenvpair@#1#2#3{%
   \@def@{environ@benv@#1}{#2}
   \@def@{environ@eenv@#1}{#3}}