Re: [NTG-context] Append to a commalist

12 Oct 2006


      Aditya Mahajan wrote:
...
On Thu, 12 Oct 2006, Hans Hagen wrote:
...
Fredrik Sjunnesson wrote:
...
Hello,
Is there a smart way to create a commalist?
I want to get the equivalent of
\setparameter[namespace][listname={item1,item2,item3}]
but be able to append one item at the time, like
\append{namepace}{listname}{item1}
\append{namepace}{listname}{item2}
\append{namepace}{listname}{item3}
I have tired this:
\def\append#1#2#3{
  \fullexpandoneargafter\doifemptyelse{\getvariable{#1}{#2}}
  {\edef\tmp{#3}}
  {\edef\tmp{\getvariable{#1}{#2},#3}}
  \setvariables[#1][#2={\tmp}]}
but it only works for one list. Apparently \tmp is not expanded so when
an item is appended to one list all other lists are affected. I have
tried \expanded but got the message stack full.
Any help would be greatly appreciated.
\def\appendtovaluelist#1#2%
 {\ifcsname#1\endcsname
    \expandafter\ifx\csname#1\endcsname\empty
      \expandafter\def\csname#1\endcsname{#2}%
    \else
      \expandafter\def\csname#1\expandafter
            \expandafter\expandafter\endcsname
         \expandafter\expandafter\expandafter{\csname#1\endcsname,#2}%
    \fi
  \else
    \expandafter\def\csname#1\endcsname{#2}%
  \fi}
% saves an argument:
\def\appendtovaluelist#1%
 {\ifcsname#1\endcsname
    \expandafter\ifx\csname#1\endcsname\empty
      \expandafter\noappendtovaluelist
\csname#1\expandafter\expandafter\expandafter\endcsname
    \else
      \expandafter\doappendtovaluelist
\csname#1\expandafter\expandafter\expandafter\endcsname
    \fi
  \else
    \expandafter\noappendtovaluelist\csname#1\expandafter\endcsname
  \fi}
\def\doappendtovaluelist#1#2{\expandafter\def\expandafter#1\expandafter{#1,#2}}
\def\noappendtovaluelist#1#2{\def#1{#2}}
\appendtovaluelist{mylist}{aap}
\appendtovaluelist{mylist}{noot}
\appendtovaluelist{mylist}{mies}
\showvalue{mylist}
What is the difference between a commalist and a valuelist :-)
\def\secondlist{}
\appendtocommalist{aap}  {\secondlist}
\appendtocommalist{noot} {\secondlist}
\appendtocommalist{mies} {\secondlist}
\showvalue{secondlist}
nothing, just the {name} thing -)


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