Document Classes ⇒ Command name concatenation

[janicki]

How can I concatenate a base name of my command with something returned by counter?
These are defined commands (theoretically may be an infinite set):
\basenamei
\basenameii
\basenameiii
I'd like to call one of them depending on what is returned by \roman{counter}.
How can I do it?

[gmedina]

Hi,

you can use conditionals. The following example illustrates a simple use of the \ifnum TeX primitive to redefine the command \example depending on the value of the counter mycount.

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\documentclass{article}

\newcounter{mycount}

\newcommand\namei{a}
\newcommand\nameii{b}
\newcommand\nameiii{c}

\newcommand\example{}

\renewcommand\example{%
  \ifnum \value{mycount}=1
  \namei\else
  \ifnum \value{mycount}=2
  \nameii\else
  \ifnum \value{mycount}=3
  \nameiii
  \else\relax
  \fi\fi\fi}

\begin{document}

\setcounter{mycount}{1}
\example

\setcounter{mycount}{2}
\example

\setcounter{mycount}{3}
\example

\setcounter{mycount}{5}
\example

\end{document}

Cahpter 13, Conditionals, of the book TeX by topic (by Victor Eijkhout) contains a useful description of the various conditionals in TeX.

[janicki]

Oh boy, READ CAREFULLY, if that was so simple, I wouldn't bother u.
I wrote that a set of commands theoretically can be infinite.
You solved problem for my simple example. What if there will be 200 of such defined commands? I can't know that number! That is why I need to concatenate command name with string returned by \roman{counter}.

[frabjous]

No need to get snippy.

I could be wrong, but I don't think it is possible to use variables of any sort in new command declarations, but likely what you're trying to accomplish can be done in a slightly different way. Can you elaborate on exactly what you're trying to do?

[josephwright]

What's wrong with

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\csname basename\roman{counter}\endcsname

or in a code block with \makeatletter active

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\@nameuse{basename\roman{counter}}

[janicki]

I could be wrong, but I don't think it is possible to use variables of any sort in new command declarations (...)

It is possible. I create "dynamically" commands this way:

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\newcommand{\addnextcommand}[3]{
	\stepcounter{counter}
	\expandafter\newcommand\expandafter{\csname basename\roman{counter}\endcsname}{#1-#2 #3}
}

I just wasn't smart enough to find out how to use them one after another.

What's wrong with

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\csname basename\roman{counter}\endcsname

There's nothing wrong with that. That is what I was looking for. Wow! That's simple. How could I miss that? Thank you. You were very helpful.