\doif(not)empty(else)

\doif(not)empty(else)

[Alan Stone]

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Hi,

Re: http://wiki.contextgarden.net/System_Macros/Branches_and_Decisions

What kind of emptyness do \doifempty, \doifnotempty, \doifemptyelse test ?

\def\ISay{}
%\def\ISay{Boe!}

\starttext

    \doifemptyelse{\ISay}{I say shhhhht}{I say \ISay}
    \blank
    \doif{\ISay}{}{I say shhhhht}
    \blank
    \doifnot{\ISay}{}{I say \ISay}

\stoptext

-- 
Best,
Alan

* TeX engine = LuaTeX
* ConTeXt  minimals ver: 2009.01.18 14:39 MKIV  fmt: 2009.1.22  int:
english/english
* Ubuntu 8.04 Hardy Heron, Windows XP SP3 Home

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Re: \doif(not)empty(else)

[Peter Münster]

On Sun, 8 Feb 2009, Alan Stone wrote:

> Re: http://wiki.contextgarden.net/System_Macros/Branches_and_Decisions
> 
> What kind of emptyness do \doifempty, \doifnotempty, \doifemptyelse test ?

Hello Alan,

Here a small test file:

\def\Empty{}
\def\Macro#1{argument is \doifemptyelse{#1}{empty}{full}}
\starttext
\quotation{Remember to expand it yourself where needed.}

\Macro{}, \Macro{blabla}

Nothing: \doifemptyelse{}{empty}{full}

\type{\Empty}: \doifemptyelse{\Empty}{empty}{full}

\type{all expanded}: \expanded{\doifemptyelse{\Empty}{empty}{full}}

\type{with \expandafter}:
\expandafter\doifemptyelse\expandafter{\Empty}{empty}{full}
\stoptext

Cheers, Peter

-- 
Contact information: http://pmrb.free.fr/contact/

___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : https://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________

Re: \doif(not)empty(else)

[Wolfgang Schuster]

Peter Münster schrieb:

> On Sun, 8 Feb 2009, Alan Stone wrote:
> 
>> Re: http://wiki.contextgarden.net/System_Macros/Branches_and_Decisions
>>
>> What kind of emptyness do \doifempty, \doifnotempty, \doifemptyelse test ?
> 
> Hello Alan,
> 
> Here a small test file:
> 
> \def\Empty{}
> \def\Macro#1{argument is \doifemptyelse{#1}{empty}{full}}
> \starttext
> \quotation{Remember to expand it yourself where needed.}
> 
> \Macro{}, \Macro{blabla}
> 
> Nothing: \doifemptyelse{}{empty}{full}
> 
> \type{\Empty}: \doifemptyelse{\Empty}{empty}{full}
> 
> \type{all expanded}: \expanded{\doifemptyelse{\Empty}{empty}{full}}
> 
> \type{with \expandafter}:
> \expandafter\doifemptyelse\expandafter{\Empty}{empty}{full}

You can use ConTeXt's \ExpandAfter:

\ExpandAfter\doifemptyelse{\Empty}{empty}{full}

> \stoptext

@Alan: It's better to use \doifsomething / \doifelsenothing because
they work also with macro content.

Wolfgang
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If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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archive  : https://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________