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Diffstat (limited to 'tex/context/base/core-env.mkiv')
| -rw-r--r-- | tex/context/base/core-env.mkiv | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tex/context/base/core-env.mkiv b/tex/context/base/core-env.mkiv index 75b65418f..fb91ba4e6 100644 --- a/tex/context/base/core-env.mkiv +++ b/tex/context/base/core-env.mkiv @@ -647,6 +647,36 @@ \expandafter\firstofoneargument \fi} +%D A few more (we could use a public test variable so that we only need +%D to expand once, assuming expandable variables): + +\letvalue{\??variables:}\empty + +\unexpanded\def\doifelseemptyvariable#1#2% + {\edef\m_syst_string_one{\csname\??variables\ifcsname\??variables#1:#2\endcsname#1:#2\else:\fi\endcsname}% + \ifx\m_syst_string_one\empty + \expandafter\firstoffourarguments + \else + \expandafter\secondoftwoarguments + \fi} + +\unexpanded\def\doifemptyvariable#1#2% + {\edef\m_syst_string_one{\csname\??variables\ifcsname\??variables#1:#2\endcsname#1:#2\else:\fi\endcsname}% + \ifx\m_syst_string_one\empty + \expandafter\firstofoneargument + \else + \expandafter\gobbleoneargument + \fi} + +\unexpanded\def\doifnotemptyvariable#1#2% + {\edef\m_syst_string_one{\csname\??variables\ifcsname\??variables#1:#2\endcsname#1:#2\else:\fi\endcsname}% + \ifx\m_syst_string_one\empty + \expandafter\gobbleoneargument + \else + \expandafter\firstofoneargument + \fi} + + \def\getvariabledefault#1#2% #3% can be command, so no ifcsname here {\executeifdefined{\??variables#1:#2}}% {#3} |