Re: [NTG-context] unusual behaviour of \if(x)

1 Jun 2011


      On Wed, Jun 1, 2011 at 3:56 PM, Hans Hagen  wrote:
...
On 1-6-2011 3:46, luigi scarso wrote:
...
On Wed, Jun 1, 2011 at 3:26 PM, Mojca Miklavec
  wrote:
...
Dear magitians,
I discovered this in LaTeX, but ConTeXt behaves the same (plain TeX
behaves differently). Can somebody please explain me why this code
fails to work? (A workaround is to move \newif on top which I'm
willing to do, but I'm still curious.)
\starttext
\ifx\hbox\undefined
 \message{invisible to tex}
 \newif\ifabc \abcfalse
 \ifabc \message{abc true breaks} \else \message{abc false breaks} \fi
\fi
\stoptext
(see wolfgang)
this works
\newif\ifabc
\starttext
\ifx\dhbox\undefined
 \message{dhbox invisible to tex}
   \abcfalse
   \ifabc \message{abc true breaks} \else \message{abc false breaks} \fi
\fi
\ifx\hbox\undefined
 \message{hbox invisible to tex}
   \abcfalse
   \ifabc \message{abc true breaks} \else \message{abc false breaks} \fi
\fi
hm, you want to start an \ifx pissing contest ... ?
\ifx\hbox\undefined
   \message{invisible to tex}
   \newif\ifabc \abcfalse
   \ifcsname ifabc\endcsname \message{abc true breaks} \else \message{abc
false breaks} \fi
\fi
no, --- infact I've said "this works", not "it's the only solution" or
" it's the perfect solution".
\ifcsname...
looks a bit strange if I'm working with \newif .


-- 
luigi