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Diffstat (limited to 'macros/latex/contrib/globalvals/globalvals.sty')
-rw-r--r-- | macros/latex/contrib/globalvals/globalvals.sty | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/macros/latex/contrib/globalvals/globalvals.sty b/macros/latex/contrib/globalvals/globalvals.sty new file mode 100644 index 0000000000..e738c95ed0 --- /dev/null +++ b/macros/latex/contrib/globalvals/globalvals.sty @@ -0,0 +1,56 @@ +% Global Vars +% +% (c) Charles Baynham 2019 +% +% License: LaTeX Project Public License 1.3c +% +% This package allow the user to declare a variable which can then be used +% anywhere else in a document, including before it was declared. This is done +% by putting the definitions into the .aux files, therefore requiring two runs +% to get it right. +% +% It implements two commands: \defVal{<value>} and \useVal{<value>}. \defVal +% sets up a global variable and \useVal recalls it. +% +% Using \defVal twice will result in an error. Using \useVal for an undefined +% value will output the text "??" +% + +\NeedsTeXFormat{LaTeX2e} +\def\@globalvalsPkgName{globalvals} +\ProvidesPackage{\@globalvalsPkgName} + [2019/02/06 v1.1 Define and use global variables throughout a document, including before their definition] + + + +% useVal@#1 will hold the value of the variable: it's defined by an .aux file +% somewhere +\newcommand{\useVal}[1]{% + \ifcsname useVal@#1\endcsname + \csname useVal@#1\endcsname + \else + ??% + \PackageWarning{\@globalvalsPkgName}{Value "#1" has not yet been defined. This may be fine, you may need to recompile. If you keep getting this message it's because you haven't defined it yet. } + \fi +} + +% useVal@#1 is defined in the .aux file to be used on the next run. +% useVal@#1@defined is defined immediately to mark that useVal@#1 has already +% been used and cannot be used again +\newcommand{\defVal}[2]{% +\ifcsname useVal@#1@defined\endcsname + \PackageError{\@globalvalsPkgName}{Value "#1" already defined}% + {You have two defVal commands which have the same parameter name. This error is occurring on the 2nd (or 3rd, or 4th...).}% +\else% + \write\@auxout{% + \unexpanded{\global\@namedef{useVal@#1}{#2}}% + }% + \global\@namedef{useVal@#1@defined}{}% + \global\@namedef{useVal@#1}{#2}% + \PackageInfo{\@globalvalsPkgName}{Defining new variable "#1" with value "#2"}% +\fi% +} + +\endinput +%% +%% End of file `globalvals.sty'.
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