card-filter.tex

% Definition of the filter language

% Helper function used to define the semantics of the filter language

% for mathematical expression used with \pgfmath<XXX>
\def\mathoperator#1#2{
  {#1}{%
    {\unexpanded{##1}}\unexpanded{\toks0=\expandafter{\intResult}%
    {##2}\toks2=\expandafter{\intResult}%
    \edef\res{\noexpand#2{\the\toks0}{\the\toks2}}%
    \res\xdef\intResult{\pgfmathresult}}%
  }%
}

% other helpers
\pgfkeys{
  /language/.cd, precedence/.is choice, operator/.is choice, value/.is choice,
  /handlers/.precedence/.code={%
    \edef\pgfkeyscurrentkey{\pgfkeyscurrentpath}\pgfkeyssplitpath{}%
    \pgfkeysalso{\pgfkeyscurrentpath/precedence/\pgfkeyscurrentname/.style={current precedence=#1}}%
  },
  /handlers/.operator expanded/.code={%
    \edef\pgfkeyscurrentkey{\pgfkeyscurrentpath}\pgfkeyssplitpath{}%
    \pgfkeysalso{%
      \pgfkeyscurrentpath/operator/\pgfkeyscurrentname/.style={current operator/.expanded=#1}
    }
  },
  /handlers/.operator/.code={%
    \edef\pgfkeyscurrentkey{\pgfkeyscurrentpath}\pgfkeyssplitpath{}%
    \pgfkeysalso{%
      \pgfkeyscurrentpath/operator/\pgfkeyscurrentname/.style={current operator=#1}
    }
  },
  /handlers/.store intResult/.code 2 args={\pgfkeysalso{%
    \pgfkeyscurrentpath/.style={current value={#1}{\xdef\intResult{#2}}}%
  }},
  /handlers/.value/.code 2 args={\pgfkeysalso{%
    \pgfkeyscurrentpath/.style={current value={#1}{#2}}
  }},
  /handlers/.same value/.code={%
    \edef\pgfkeyscurrentkey{\pgfkeyscurrentpath}\pgfkeyssplitpath{}%
    \edef\helper{current value={#1}{\pgfkeyscurrentname}}%
    \pgfkeysalso{%
      \pgfkeyscurrentpath/\pgfkeyscurrentname/.style/.expand once=\helper
    }
  }
}

% Definition of syntax and semantics of the filter language for cards
\pgfkeys{
  /language/.cd,
  % Define operator precedences
  or/.precedence=2,
  and/.precedence=3,
  </.precedence=4,
  >/.precedence=4,
  eq/.precedence=4,
  <>/.precedence=4,
  +/.precedence=5,
  */.precedence=6,
  -/.precedence=5,
  % Define types and semantics of operators
  bool and bool/.operator expanded=\mathoperator{bool}{\pgfmathand},
  bool or bool/.operator expanded=\mathoperator{bool}{\pgfmathor},
  %
  number + number/.operator expanded=\mathoperator{number}{\pgfmathadd},
  number * number/.operator expanded=\mathoperator{number}{\pgfmathmultiply},
  number - number/.operator expanded=\mathoperator{number}{\pgfmathsubtract},
  number < number/.operator expanded=\mathoperator{bool}{\pgfmathless},
  number > number/.operator expanded=\mathoperator{bool}{\pgfmathgreater},
  number eq number/.operator expanded=\mathoperator{bool}{\pgfmathgreater},
  %
  type eq type/.operator={bool}{\xdef\intResult{\ifnum\pdfstrcmp{##1}{##2}=0 1 \else 0 \fi}},
  type <> type/.operator={bool}{\xdef\intResult{\ifnum\pdfstrcmp{##1}{##2}=0 0 \else 1 \fi}},
  %
  title eq title/.operator={bool}{\xdef\intResult{\ifnum\pdfstrcmp{##1}{##2}=0 1 \else 0 \fi}},
  title <> title/.operator={bool}{\xdef\intResult{\ifnum\pdfstrcmp{##1}{##2}=0 0 \else 1 \fi}},
  %
  % Define types and semantics of values
  value/true/.store intResult={bool}{1},
  value/false/.store intResult={bool}{0},
  %
  value/0/.store intResult={number}0,
  value/1/.store intResult={number}1,
  value/2/.store intResult={number}2,
  value/3/.store intResult={number}3,
  value/4/.store intResult={number}4,
  value/4+/.store intResult={number}4.5,
  value/5/.store intResult={number}5,
  value/6/.store intResult={number}6,
  value/7/.store intResult={number}7,
  value/8/.store intResult={number}8,
  value/9/.store intResult={number}9,
  %
  value/level/.store intResult={number}{\cardLevel},
  %
  value/type/.value={type}{\cardType},
  value/Item/.same value=type,
  value/Action/.same value=type,
  value/Spell/.same value=type,
  value/Cantrip/.same value=type,
  value/Focus/.same value=type,
  value/Rule/.same value=type,
  value/Condition/.same value=type,
  %
  value/title/.value={title}{\cardTitle},
  value/title/.unknown/.code={
    \edef\currentname{\pgfkeyscurrentname}
    \pgfkeysalso{current value/.expanded={title}{\currentname}}
  }
}

% Convenience layer for filtering

\pgfkeys{
  /card attributes/.cd,
  type/.estore in=\cardType,
  level/.estore in=\cardLevel,
  level/.append code={\ifnum\pdfstrcmp{\cardLevel}{}=0 \edef\cardLevel{-1}\fi},
  level/.append code={\ifnum\pdfstrcmp{\cardLevel}{4+}=0 \edef\cardLevel{4.5}\fi},
  title/.estore in=\cardTitle,
  source book/.estore in=\cardSourceBook,
  collection value/.estore in=\cardCollectionValue
}

\def\allowedControlSequencesForFilteringCards{
  \def\and{and}%
  \def\or{or}%
  \def\title{title}%
  \def\level{level}%
  \def\type{type}%
  \def\ne{<>}%
}

\NewDocumentEnvironment{filterBy}{}{%
  \let\allowedControlSequences=\allowedControlSequencesForFilteringCards
  \startExpression
}{%
  \ifnum \pdfstrcmp{\currentType}{bool}=0 \else
    \errmessage{Wrong type of filter expression, expected bool but got \currentType}
  \fi
  \global\let\cardFilter=\currentCalc
}

\NewDocumentCommand\ifVisible{o}{%
  \pgfqkeys{/card attributes}{#1}%
  \cardFilter
  \ifnum\intResult=1
  \clearpage
  \writeMetadata
}

% Write metadata information about some file

\immediate\newwrite\metadataFile
\immediate\openout\metadataFile=metadata.txt

\pgfkeys{
  /collections/all/.style={},
  /collections/by name/.code={%
    \pgfkeysalso{/collections/#1}%
    \ifnum\intResult=1
      \immediate\write\metadataFile{ collection=#1}
    \fi
  }
}

\NewDocumentEnvironment{collection}{m}{%
  \let\allowedControlSequences=\allowedControlSequencesForFilteringCards
  \startExpression
}{%
  \ifnum \pdfstrcmp{\currentType}{bool}=0 \else
    \errmessage{Wrong type of collection expression, expected bool but got \currentType}
  \fi
  \global\let\collectionCurrentCalc=\currentCalc
  \gdef\evalAfterGroup{
    \pgfkeys{
      /collections/#1/.code/.expand once=\collectionCurrentCalc,
      /collections/all/.append style={/collections/by name=#1}
    }
  }
  \aftergroup\evalAfterGroup
}

\def\writeMetadata{
  \immediate\write\metadataFile{page=\thepage}%
  \immediate\write\metadataFile{ title=\cardTitle}%
  \immediate\write\metadataFile{ level=\cardLevel}%
  \immediate\write\metadataFile{ type=\cardType}%
  \immediate\write\metadataFile{ source book=\cardSourceBook}%
  \immediate\write\metadataFile{ source file=\CurrentFilePath/\CurrentFile}%
  \ifnum\pdfstrcmp{\cardCollectionValue}{}=0\else
    \immediate\write\metadataFile{ collection value=\cardCollectionValue}%
  \fi
  \pgfkeys{/collections/all}%
}

% Implementation of semantics and type-checking

% Set up pgfkeys to forward values to the correct macros

\pgfkeys{
  /language/current precedence/.code={%
    \pgfmathparse{\basePrecedence + #1}
    \xdef\nextPrecedence{\pgfmathresult}%
  },
  /language/current value/.code 2 args={%
    \edef\currentType{#1}%
    \def\currentCalc{#2}%
  },
  /language/current operator/.code 2 args={%
    \edef\currentType{#1}
    \def\helper##1##2{#2}
    \toks0=\expandafter{\currentCalc}
    \toks2=\expandafter{\nextCalc}
    \edef\currentCalc{%
      \noexpand\helper{\the\toks0}{\the\toks2}%
    }%
    \edef\currentCalc{%
      \unexpanded\expandafter\expandafter\expandafter{\currentCalc}%
    }%
  }
}

% entrypoint
\def\startExpression{
  \xdef\basePrecedence{0}%
  \edef\currentPrecedence{0}%
  \edef\currentOperator{}%
  \continueWithValue
}

\def\continue#1{
  \def\currentToken{#1}
  \def\a{\end}\def\b{)}%
  \ifx\a\currentToken
    % finish
    \closeLevels
    \expandafter\end
  \else\ifx\b\currentToken
      \pgfmathparse{int(\basePrecedence-1000)}%
      \xdef\basePrecedence{\pgfmathresult}%
      \expandafter\expandafter\expandafter\continue
    \else
      \expandafter\expandafter\expandafter\continueWithOperator
    \fi
  \fi
}

\def\continueWithOperator{
  \parseOperator
  \pgfqkeys{/language}{precedence/.expanded=\nextOperator}
  \endgroupsPrecedence
  \edef\currentOperator{\nextOperator}
  \begingroup
  \edef\currentOperator{}
  \edef\currentPrecedence{\nextPrecedence}
  \continueWithValue
}

\def\continueWithValue#1{
  \def\a{(}
  \def\b{#1}
  \ifx\a\b
    \pgfmathparse{\basePrecedence+1000}%
    \xdef\basePrecedence{\pgfmathresult}%
    \expandafter\continueWithValue
  \else
    \parseValue{#1}
    \pgfqkeys{/language}{value/.expanded=\currentValue}
    \expandafter\continue
  \fi
}

\def\allowedControlSequences{}

\def\parseOperator{
  {
    \allowedControlSequences
    \xdef\nextOperator{\currentToken}
  }
  \xdef\eqToken{=}
  % convert = to eq to support pgfkeys better
  \ifx\nextOperator\eqToken \xdef\nextOperator{eq} \fi
}

\def\parseValue#1{%
  {%
    \allowedControlSequences
    \xdef\currentValue{#1}%
  }%
}

\def\promoteCurrentType{
  \def\empty{}%
  \ifx\empty\currentOperator
    \edef\currentType{\nextType}
    \edef\currentCalc{\unexpanded\expandafter{\nextCalc}}
  \else
    \pgfqkeys{/language}{operator/.expanded=\currentType\space\currentOperator\space\nextType}
  \fi
}

\def\endgroupsPrecedence{
  \pgfmathparse{\nextPrecedence<\currentPrecedence} %
  \ifnum\pgfmathresult=1
    \xdef\nextType{\currentType}
    \xdef\nextCalc{\unexpanded\expandafter{\currentCalc}}
    \endgroup
    \promoteCurrentType
    \endgroupsPrecedence
  \fi
}

\def\closeLevels{
  \xdef\initialBasePrecedence{0}
  \ifx\basePrecedence\initialBasePrecedence
    \xdef\nextPrecedence{0}
    \endgroupsPrecedence
  \else
    \pgfmathparse{\basePrecedence / 1000}%
    \errmessage{Not enough closing brackets at end of expression, \pgfmathresult\space brackets missing}%
  \fi
}