while (<DATA>) {
  if (/foo/) {
    print "Found 'foo'\n";
  };
  if (/bar/) {
    print "Found 'bar'\n";
  };
  if (/baz/) {
    print "Found 'baz'\n";
  };

  print "Unknown line: $_";
};
__DATA__
foozle
bazzle
barren

##</code><code>##

my @items =(
  sub { /foo/ and do {
      print "Found 'foo'\n";
  }},
  sub { /bar/ and do {
      print "Found 'bar'\n";
  }},
  sub { /baz/ and do {
      print "Found 'baz'\n";
  }},
  sub {
    print "Unknown line: $_";
    undef
  },
);

my @current = @items;
while (defined (my $line = <DATA>)) {
  my @remaining = @current;
  @current = ();
  local $_ = $line;
  CODE: while (my $c = shift @remaining) {
    if ($c->()) {
      push @current, @remaining;
      last # CODE
    } else {
      push @current, $c;
    };
  };
};

__DATA__
foozle
--- #1
bazzle
--- #2
barren
--- #3