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返回布尔值的新命令

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返回布尔值的新命令

我正在使用etoolbox。如何创建返回布尔值的新命令？例如，如果我创建以下命令：

\newcommand\ifkeyempty[1]{
    \def\novalue{\pgfkeysnovalue}%
    \def\empty{}%
    \pgfkeysgetvalue{#1}{\value}%
    \ifboolexpr{test {\ifdefequal{\value}{\empty}} or test {\ifdefequal{\value}{\novalue}}}{true}{false}%
}

我希望能够在这样的布尔表达式中使用它：

    \ifboolexpr{test {\ifkeyempty{/keyname}} or ... }{expression is true}{expression is false}

这可能吗？

答案1

哇！其实很简单！我只是在命令定义中删除了表达式为真或为假时应执行的子句。现在，它既可以在测试中使用，也可以\ifboolexpr直接使用\ifkeyempty{<key>}{<true>}{<false>}。

\documentclass{article}
\usepackage{tikz}
\usepackage{etoolbox}

\pgfkeys{
    /foo/.initial,
    /bar/.initial,
}

\newcommand\ifkeyempty[1]{
    \def\novalue{\pgfkeysnovalue}%
    \def\empty{}%
    \pgfkeysgetvalue{#1}{\keyvalue}%
    \ifboolexpr{test {\ifdefequal{\keyvalue}{\empty}} or test {\ifdefequal{\keyvalue}{\novalue}}}%
}

\begin{document}

\ifboolexpr{test {\ifkeyempty{/foo}} and test {\ifkeyempty{/bar}}}{expression is true}{expression is false}
\ifkeyempty{/foo}{foo is empty}{foo is not empty}

\pgfkeys{/foo=value1}
\ifboolexpr{test {\ifkeyempty{/foo}} and test {\ifkeyempty{/bar}}}{expression is true}{expression is false}
\ifkeyempty{/foo}{foo is empty}{foo is not empty}

\pgfkeys{/bar=value2}
\ifboolexpr{test {\ifkeyempty{/foo}} and test {\ifkeyempty{/bar}}}{expression is true}{expression is false}
\ifkeyempty{/foo}{foo is empty}{foo is not empty}

\pgfkeys{/foo=}
\ifboolexpr{test {\ifkeyempty{/foo}} and test {\ifkeyempty{/bar}}}{expression is true}{expression is false}
\ifkeyempty{/foo}{foo is empty}{foo is not empty}

\pgfkeys{/bar=}
\ifboolexpr{test {\ifkeyempty{/foo}} and test {\ifkeyempty{/bar}}}{expression is true}{expression is false}
\ifkeyempty{/foo}{foo is empty}{foo is not empty}

\end{document}

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