Perl6-for-Beginners-Oneliners.tex

\subsection{One Liners}

\begin{frame}[fragile]{Killer App: One Liners}
\begin{block}<1->{Doing One Liners with Perl 6}
Perl has always been famous for it's one-liners. Let's continue \ldots
\begin{itemize}
\item<1-> Strip trailing whitespaces \lstinline[language=sh,inputencoding=latin9]!perl6 -pe 's/\s*$//'!
Looks familiar, doesn't it?
\item<2-> Most use is very likely the line ending tidying - done easily in Perl 6 by \lstinline[language=sh,inputencoding=latin9]!perl6 -pe ''!
Yes - it's completely built-in. An empty by-line job does \lstinline[language=sh,inputencoding=latin9]!perl5  -p -i -e 's/\012?\015/\n/g'!
\item<3-> Another famous job is filtering, like \lstinline[language=sh,inputencoding=latin9]!perl6 -ne '.say if .is-prime'!
\item<4-> Adding line numbers to some inputfile needed? How about
\begin{lstlisting}[language=sh,inputencoding=latin9]
perl6 -ne 'for lines.kv -> $no, $l {\
say sprintf("%04d: %s", $no, $l) }'
\end{lstlisting}
\item<5-> Maybe a bit more flexibility in width of line-numbers?
\begin{lstlisting}[language=sh,inputencoding=latin9]
perl6 -e 'my @l = lines; \
my $fmt = "\%0" ~ @l.elems.chars ~ "d: %s"; \
for ^@l.elems {say sprintf($fmt, $_+1, @l[$_]) }'
\end{lstlisting}
\end{itemize}
\end{block}
\end{frame}