Re: \vspace

[Hans Hagen <pragma@wxs.nl>]

Wolfgang Schuster wrote:
> Hi Hans,
> 
> can you add a \vspace command which behaves like \hspace but for vertical mode,
> there are some cases where \blank is not so well suited (i know the \??vs namespace
> is already used by \blank)
> 
> \def\definevspace
>   {\dotripleempty\dodefinevspace}
> 
> \def\dodefinevspace[#1][#2][#3]%
>   {\ifthirdargument
>      \setvalue{\??vs#1:#2}{#3}%
>    \else
>      \setvalue{\??vs:#1}{#2}%
>    \fi}
> 
> \unexpanded\def\vspace
>   {\dodoubleempty\dohspace}

hm, untested ...   ^^^^^^^^^

> \def\dovspace[#1][#2]%
>   {\ifsecondargument
>      \dodovspace[#1][#2]%
>    \else\iffirstargument
>      \vspace[][#1]%
>    \else
>      \vspace[][\s!default]%
>    \fi\fi}
> 
> \def\dodovspace[#1][#2]%
>   {\vskip\vspaceamount{#1}{#2}}
> 
> \def\vspaceamount#1#2%
>   {\executeifdefined{\??vs#1:#2}{\executeifdefined{\??vs:#2}\zeropoint}}

i'm always a bit relucate to let users mess with vertical spacing ... 
anyhow, in \hspace we clean up preceding space so vspace should behave 
the same i.e. there should be a \removelastskip before the vskip

\def\dodovspace[#1][#2]%
   {\par
    \ifvmode
      \removelastskip
      \vskip\vspaceamount{#1}{#2}\relax
    \fi}

i'll add it but we should not encourage too much in using it, that is, 
i'm *not* going to look into spacing related bug reports that use this 
command

Hans


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                                           Hans Hagen | PRAGMA ADE
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