[NTG-context] Remove leading spaces

2009-02-05 Thread Bart C. Wise 
When a function is called, I would like to remove any leading space.  Then the 
function can control the spacing.  If I don't remove spaces, it then makes a 
difference whether or not I have a space before the function is called.

I would like the output of the following two lines to be equal:
This is a \MyFunction[1] test.
This is a\MyFunction[1] test.

However, they are not because the first line has a space before the function 
call.  

\def\MyFunction{\dosingleempty\doMyFunction}
\def\doMyFunction[#1]{%
\processaction[#1]%
[1=\medspace dog ,%
 2=\medspace cat ,%
 default=\ldots]%
}

\starttext
Test1: This is a\MyFunction[1] test.

Test2: This is a \MyFunction[1] test.

Test3: This is a \MyFunction test.

Test4: This is a\MyFunction test.
\stoptext

Is there a way to do this and not cause any side effects?

Thanks,
Bart
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Re: [NTG-context] Remove leading spaces

2009-02-05 Thread Wolfgang Schuster 


Am 05.02.2009 um 21:26 schrieb Bart C. Wise:

When a function is called, I would like to remove any leading space.  
Then the function can control the spacing. If I don't remove spaces,  
it then makes a difference whether or not I have a space before the  
function is called.


Is there a way to do this and not cause any side effects?


You can use \removeunwantedpsaces to remove preceding spaces before
your command and \ignorespaces to gobble spaces after your command.

A faster version of your macro is:

\def\MyFunction
  {\dosingleempty\doMyFunction}

\def\doMyFunction[#1]%
  {\removeunwantedspaces\executeifdefined{myfunction:#1} 
{\getvalue{myfunction:default}}}


\setvalue{myfunction:1}{\medspace dog }
\setvalue{myfunction:2}{\medspace cat }
\setvalue{myfunction:default}{\ldots}

Wolfgang

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Re: [NTG-context] Remove leading spaces

2009-02-05 Thread Bart Wise 
On Thursday 05 February 2009 01:36:16 pm Wolfgang Schuster wrote:
 Am 05.02.2009 um 21:26 schrieb Bart C. Wise:
  When a function is called, I would like to remove any leading space.
  Then the function can control the spacing. If I don't remove spaces,
  it then makes a difference whether or not I have a space before the
  function is called.
 
  Is there a way to do this and not cause any side effects?

 You can use \removeunwantedpsaces to remove preceding spaces before
 your command and \ignorespaces to gobble spaces after your command.

 A faster version of your macro is:

 \def\MyFunction
{\dosingleempty\doMyFunction}

 \def\doMyFunction[#1]%
{\removeunwantedspaces\executeifdefined{myfunction:#1}
 {\getvalue{myfunction:default}}}

 \setvalue{myfunction:1}{\medspace dog }
 \setvalue{myfunction:2}{\medspace cat }
 \setvalue{myfunction:default}{\ldots}


Thanks Wolfgang for the answer!
And thanks for the coding hints, they are always appreciated!

Bart
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