On Mon, 25 Apr 2011, Vedran Miletić wrote:

> 2011/3/7 Aditya Mahajan <adityam@umich.edu>
>
>> On Sun, 6 Mar 2011, Curiouslearn wrote:
>>
>>  I am making some slides using the Swoosh style in simpleslides module.
>>> I wanted to reveal some content sequentially.
>>>
>>
>> simpleslides does not support stepwise presentation of material.
>>
>> I occasionally use the following macros for quick and dirty stepwise
>> effects. This is for really simple material (no counters, no glues ...)
>>
>> \usemodule[simpleslides][style=Swoosh]
>> \def\StartSteps#1#2\StopSteps%
>>   {\dorecurse{#1}{\long\setvalue{\recurselevel}{\gobble}}
>>    \dorecurse{#1}{\long\setvalue{\recurselevel}{\oneofone} #2}}
>>
>> \long\def\gobble#1{}
>> \long\def\oneofone#1{#1}
>>
>> \starttext
>> \StartSteps{3}
>>
>> \SlideTitle{Context can be used for \dots}
>>
>> \null
>>
>> \startitemize[n]
>>  \2{\item Writing your articles}
>>
>>  \3{ \item Making slides for presentations }
>> \stopitemize
>>
>> \StopSteps
>>
>> \stoptext
>
>
> Hi,
>
> this is awesome, but could you please explain why it works? I don't 
> understand what is defined by \def\StartSteps#1#2\StopSteps and also

\def\StartSteps#{count}#{body}\StopSteps
    {% Initialization
     % for i = 1 upto count :
     %   set csname(i) = gobble
     \dorecurse{#{count}}{\long\setvalue{\recurselevel}{\gobble}}
     %
     % Now typeset #{body} for #{count} number of times.
     % In each iteration set csname(i) = oneofone
     \dorecurse{#{count}}
         {\long\setvalue{\recurselevel}{\oneofone}%
          #2}}

> why are \gobble and \oneofone used in such a way when they are 
> single-argument commands.

I could have just \letvalue{\recurselevel}\gobble and 
\letvalue{\recurselevel}\oneofone.

Aditya