Vyplnovani formulare -- ztrata mezer

[Petr Mandys]

Dekuji za pomoc.

Jen se chci jeste zeptat, proc jste zavadel \cnvnext a nedefinoval jste
primo \doconvert s \afterassingment misto s \futurelet?

Jeste by me zajimalo, zda by se nedal \spacetoken definovat nejak
jednoduseji? Nicmene takove makro se mi libi a trochu jsem si ho zobecnil

\edef\expandlet#1#2{\let\noexpand#1= #2}

Pak ho mohu pouzit jako
\expandlet\spacetoken\space

Jeste jednou dekuji

Petr Mandys

On Thu, 27 Mar 2003, Petr Olsak wrote:

>
> On Wed, 26 Mar 2003, Petr Mandys wrote:
>
> > Zdravim!
> >
> > Myslenka je jasna: Budu si odebirat postupne znaky a centrovat je do
> > \hboxu potrebne sirky, ktere pak budu skladat za sebe...
> >
> > V cem je teda problem: Jak zajistit, aby mi nemizely mezery? Odebirani po
> > znaku delam pomoci makra
> >
> > \def\vytiskni#1{\expandafter\odebertoken#1;}
> > \def\odebertoken#1#2;{\zpracuj{#1}\odebertoken#2;}
> >
> > (velmi zjednodusene napsano...) Jenze mezera se mi v takovem pripade
> > sezere, jako nepovinna mezera pred parametry makra...
>
> Je potreba pouzit \futurelet. Muzete se podivat do kodu nize, ve kterem
> rozebiram taky jednotlive tokeny a davam pozor, abych neznicil mezeru.
> Je to sice o necem jinem, ale princip je stejny.
>
> Kod jsem poslal panu Hagenovi, kdyz potreboval ve vystupech \specialu
> konvertovat vyskyty znaku ( na dvojici \(. Potreboval to
> pravdepodobne nekam do ConTeXtu.
>
> Zdravim
>
> Petr Olsak
>
> ----------------------------------------
>
> On Thu, 23 Jan 2003, Hans Hagen wrote:
>
> > Hi Petr,
> >
> > How about output conversion:
> >
> > say that i want to write a ( to a PS file, then it needs to be escaped to
> > \( ; does you rmechanism also work on that end (writes, specials)
>
> I decided that the implementation of the conversion you asked is not
> a simple task in encTeX. There exist a solution of this task on macro
> level. May be, you are using a similar solution.
>
> \def\convert #1{\def\cnvout{}\doconvert #1\convert}
>
> % The macro \convert copies its parameter to the body of the macro
> % \cnvout and does the conversion "(" -> "\(", ")" -> "\)".
> % If the "{" or "}" occurs in the parameter then the ASCII code of this
> % character is kept but catcode will be changed to 11.
> % All another tokens (including control sequences) are copied
> % without any changes.
>
> \def\doconvert {\futurelet\next\testtoken}
>
> \def\testtoken{\ifx\next\convert \let\next=\cnvfinal
>   \else \ifx\spacetoken\next \let\next=\insertspace
>   \else \ifx\bgroup\next \let\next=\insertbracein
>   \else \ifx\egroup\next \let\next=\insertbraceout
>   \else \ifx(\next \let\next=\insertescape
>   \else \ifx)\next \let\next=\insertescape
>   \else \let\next=\inserttoken
>   \fi\fi\fi\fi\fi\fi \next}
>
> \let\ex=\expandafter
>
> \def\cnvfinal#1{}
> \def\cnvnext{\afterassignment\doconvert \let\next= }
> \def\addcnvout #1{\ex\def \ex\cnvout \ex{\cnvout#1}}
> \def\inserttoken #1{\addcnvout #1\doconvert}
> \def\insertescape #1{\ex\addcnvout\ex{\normalbackslash#1}\doconvert}
> \def\insertbracein {\ex\addcnvout \normalbracein \cnvnext}
> \def\insertbraceout {\ex\addcnvout \normalbraceout \cnvnext}
> \def\insertspace {\addcnvout { }\cnvnext}
>
> \bgroup
>   \uccode`X=`\\ \uppercase{\gdef\normalbackslash{X}}
>   \uccode`X=`\{ \uppercase{\gdef\normalbracein{X}}
>   \uccode`X=`\} \uppercase{\gdef\normalbraceout{X}}
> \egroup
> \edef\next{\let\noexpand\spacetoken= \space}\next
>
> % There is a sketch ot hte macros used for \shipout and \write
> % with the use of the \convert macro.
>
> \def\yourspecial #1{...
>    \convert {#1}\special{text to dvi: "\cnvout", etc.}%
> }
> % No \toks are needed because the expansion is done immediatelly.
>
> \def\yourwrite #1{...
>    \convert {#1}\toks0=\expandafter{\cnvout}
>    \edef\next{\write\fileout{text to write, "\the\toks0", etc.}}\next
> }
> % We partially expand the write argument because the full expansion is
> % done late when the \cnvout can have a new value.
> % The full expansion of \cnvout by \edef is not recommended because it
> % may include the control sequences no-expanded and converted to the
> % <byte_sequences> by encTeX.
>
> Petr Olsak
>
>