Ron Rivest writes:
> (*) A Post tag system has a number of rewrite rules of the form
> L_i --> R_i
> where L_i and R_i are strings over some alphabet (e.g. binary).
> As long as the prefix of the input matches some L_i, that
> L_i is removed from the beginning of the input, and the
> replacement R_i is added to the end of the input.
You mean like:
#!/usr/bin/perl
# usage: post-tag '01-->02' '002-->3'
# tests: 01 002 010 00201
while($_=shift) {
die unless m/(.*)-->(.*)/;
push(@L, $1);
push(@R, $2);
}
while(<>) {
chomp;
do {
for($i=0; $i < @L; $i++) {
$l=$L[$i];
$r=$R[$i];
print "$_ trying $l-->$r\n";
last if s/^$l(.*)/$1$r/;
}
print "$_ restarting\n" if ($i < @L);
} while ($i < @L);
print "$_\n";
}
--
-russ nelson <[EMAIL PROTECTED]> http://russnelson.com
Crynwr sells support for free software | PGPok | Government schools are so
521 Pleasant Valley Rd. | +1 315 268 1925 voice | bad that any rank amateur
Potsdam, NY 13676-3213 | +1 315 268 9201 FAX | can outdo them. Homeschool!
