Thomas A. Schmitz thomas.schmitz at uni-bonn.de
Thu Sep 4 09:39:33 CEST 2008

Aditya, Peter,

as always, thanks a lot for your help. Peter, you're certainly right
that it's difficult to diagnose my problem - I'm sending only
snippets, no example. But it's a fairly complex thing here for my
presentation module and difficult to reduce in size.

On Sep 3, 2008, at 6:58 PM, Aditya Mahajan wrote:

> On Wed, 3 Sep 2008, Thomas A. Schmitz wrote:
>
>> Hi all,
>>
>> I'm trying to define a macro \Command which can either have four or
>> five arguments. If it has five, I want to define them as
>>
>> \Command1[#1][#2][#3][#4]{#5}
>>
>> if it has four, as
>>
>> \Command2[#1][#2][#3]{4#}
>>
>> I thought this would be the way to go:
>>
>> \def\Command{%
>
> You need something with possibly five arguments so you should use
> quint
>
> \def\Command%
>    {\doquintupleargument\doCommand}
>
>> \def\doCommand{%
>> 	\iffifthargument%
>> 	\else%
>> 		\dotripleargument\Command2%
>> 	\fi}
>
>
> The usual way is
>
> \def\doCommand[#1][#2][#3][#4][#5]%
>    {\doifelsenothing{#5}%See below
>     {\Command1[#1][#2][#3][#4][#5]}
>     {\Command2[#1][#2][#3][#4]}}
>
> I use \doifelsenothing rather than \doiffirthargument. If I give
>
> \Command[...][...][...][...][] with \doifelsenothing \Commnad2 will be
> called while with \iffifthargument \Command1 will be called. Use
> whichever
> is more appropriate for your problem.
>
OK, that does make sense, but now I also see where my problem lies.
When I define

\doCommand[#1][#2][#3][#4]#5

and then have

\Command2[#1][#2][#3]#4

TeX picks up a closing bracket as #4. I suspect that my problem lies
in the definition \doCommand[#1][#2][#3][#4]#5 . The two definitions
don't match; when I look at \doCommand, the closing bracket is indeed
argument #4, from TeX's point of view. Maybe I need to reverse the
order of my arguments and make it

\doCommand#1[#2][#3][#4][#5] ?

but I'm not sure if this would play with quintupleempty...

Anyway, thanks a lot for your help. I'll look further into it and will
maybe come back with a real example later if I can't figure it out.

Thomas