Spec Echoer

Outputs tuples of the echoRepeats last elements of the input stream.

/*!
 * @class Echoer
 * 
 * @extends Pipe
 * 
 * @headerfile <seqan/pipe.h>
 * 
 * @brief Outputs tuples of the <tt>echoRepeats</tt> last elements of the input
 *        stream.
 * 
 * @signature template <typename Input, unsigned ECHO_REPEATS, bool OMIT_FIRST>
 *            class Pipe;
 * 
 * @tparam TInput The type of the pipeline module this module reads from.
 * @tparam ECHO_REPEATS The tuple length.The tuples contain elements
 *                      <tt>in[i]in[i-1]...in[i-(echoRepeats-1)]</tt>.
 * @tparam OMIT_FIRST Omit half filled tuples. If <tt>true</tt>, the output
 *                    stream is <tt>echoRepeats-1</tt> elements shorter than the
 *                    input stream. If <tt>false</tt>, the lengths are identical
 *                    and the tuple is filled with blanks (default constructed
 *                    elements) for undefined entries.
 * 
 * The output type is a @link Tuple @endlink of input elements and length
 * <tt>echoRepeats</tt> (i.e. <tt>Tuple&lt;Value&lt;TInput&lt;::Type,
 * echoRepeats&gt;</tt>).
 * 
 * The tuples are sequences of the form
 * <tt>in[i]in[i-1]in[i-2]..in[i-echoRepeats+1]</tt>. For
 * <tt>omitFirst=false</tt> <tt>i</tt> begins with 0 and for
 * <tt>omitFirst=true</tt> <tt>i</tt> begins with <tt>echoRepeats-1</tt>.
 */