steph_bow asked "could you tell me what is the signification of (?<!\d) in your code ?"

The purpose of the negative look behind assertions in my regular expression was to ensure that there was a key included in the data value. This was not strictly part of your stated requirement, but it seemed implied and therefore should be enforced.

If this didn't matter, than we could simply rely on non-greedy matching in order to separate the key from the suffix. 

while (<DATA>) {
    chomp;
    if (m{\A (.*?) (\d+ | [A-Z]+) \z}x) {
        printf "Key = %-6s - Suffix = %s\n", $1, $2;
    } else {
        die "Invalid data: $_";
    }
}

__DATA__
AAA30
BBC5
SHT12H
DAL33B
BBC49
AAA31
BBC8
BBC3
DAL33A
BBC6
SHT12G
BBC50

[download]

However, what about the case of a value of '123456' or 'ABCDEF'? Currently those two values would validate to a key of the empty string "", and a suffix of the entire string. To avoid this, we start by changing the key matching from * (0 or more) to + (1 or more). However, this will just eat up 1 character of our suffix. We therefore add negative look behind assertions to the suffix matching in order to ensure that the suffix is matched on a boundary.

This might have been a little obsessive, but it's always a good idea to validate your data so that you are absolutely sure that the rules of your logic are being followed.

- Miller

In reply to Re^2: searching for strings by wind
in thread searching for strings by steph_bow

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