It's not the same thing. He's using the regex as a key with the corresponding code/action as the value to that key. He could write: 
my %REGEX = (
    header    = [qr/^(?!START:|END:)([^*: ][^:]+):(.+)\n/, \&header],
    starttime = [qr/^START:\s*(.+)\n/, \&etc],
    endtime   = [qr/^END:\s*(.+)\n/, \&etc],
    lineitem  = [qr/^(?:\* |  )([^:]+):(\d+):(.+)\n/, \&etc]
);
#...
#You could even use constants here to make things easier.
# 0 = RE; 1 = FUNCTION; or something.
for my $rex_table (keys %REGEX) {
  if (my @m = $line =~ $rex_table->[0]) {
    $rex_table->[1]->($r,@m);
    next LINE;
  }
}

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Which I, personally, think is preferable. The implementation of the dispatch table depends really on implementation. I like to have the name of the action as a 'key', so that the code's self-documenting, but you could also use the array aproach previously shown.

In reply to Re^2: Munging with a regex dispatch table by Anonymous Monk
in thread Munging with a regex dispatch table by Solo

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