conditionalsmacros
I'm trying to compile a LaTeX code with an older version of some package. Thus, I'm having a few issues due to undefined commands.
How can I add conditional code so that I can define some work-around commands of this older package version?
% I want something like this:
if command \foobar is not defined
\newcommand{\foobar}{FooBar}
% I don't need an "else" clause here, but it would be good
% to know how to add one, in case I need it in future
end if
In the documentation you can find \algnewcommand. In relation \Require is defined as
\algnewcommand\algorithmicrequire{\textbf{Require:}}
So you can do:
\algnewcommand\algorithmicinput{\textbf{INPUT:}}
\algnewcommand\INPUT{\item[\algorithmicinput]}
Here is a complete example:
\documentclass[a4paper,11pt]{article}
\usepackage{algorithmicx}
\usepackage{algorithm}
\usepackage{algpseudocode}
\algnewcommand\algorithmicinput{\textbf{INPUT:}}
\algnewcommand\INPUT{\item[\algorithmicinput]}
\begin{document}
\begin{algorithmic}[1]
\INPUT foo
\Require $x\ge5$
\Ensure $x\le-5$
\Statex
\While{$x>-5$}
\State $x\gets x-1$
\EndWhile
\end{algorithmic}
\end{document}
It is an expansion issue. You should expand \condition before pass it to \ifthenelse. Use
\expandafter\ifthenelse\expandafter{\condition}{% if condition returns true
True.
}{% if condition returns false
False.
}
you will get correct result.
Best Answer
The LaTeX kernel command
\providecommand{\foobar}{FooBar}does exactly what you want.