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From: luigi scarso <luigi.scarso@gmail.com>
To: mailing list for ConTeXt users <ntg-context@ntg.nl>
Subject: Re: unusual behaviour of \if(x)
Date: Wed, 1 Jun 2011 16:01:52 +0200	[thread overview]
Message-ID: <BANLkTikqBgGfFjFek9ad4_yVk1CtO7WFWA@mail.gmail.com> (raw)
In-Reply-To: <4DE644F6.5070107@wxs.nl>

On Wed, Jun 1, 2011 at 3:56 PM, Hans Hagen <pragma@wxs.nl> wrote:
> On 1-6-2011 3:46, luigi scarso wrote:
>>
>> On Wed, Jun 1, 2011 at 3:26 PM, Mojca Miklavec
>> <mojca.miklavec.lists@gmail.com>  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
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  reply	other threads:[~2011-06-01 14:01 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-01 13:26 Mojca Miklavec
2011-06-01 13:36 ` Wolfgang Schuster
2011-06-01 13:52   ` Mojca Miklavec
2011-06-01 14:08     ` Hans Hagen
2011-06-01 14:10     ` luigi scarso
2011-06-01 13:46 ` luigi scarso
2011-06-01 13:56   ` Hans Hagen
2011-06-01 14:01     ` luigi scarso [this message]
2011-06-01 14:09       ` Wolfgang Schuster

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