As well as representing sequences, ranges may also be used as
For example, the
following code fragment prints sets of lines from standard input,
where the first line in each set contains the word ``start'' and the
last line the word ``end.''
print if /start/../end/
Behind the scenes, the range keeps track of the state of each of the
tests. We'll show some examples of this in the description of loops
that starts on page 82.