Increment a mixed alphanumeric

miketosh has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to increment a string matching /[A-Z][A-Z0-9]+/ but cannot use the ++ operator, since the last character could be A-Z. My needs are to make sure I haven't seen this string before, and keep the first character the same. Is there a way to convert to a number, increment, and convert back to a string?

Here is what I have so far, that I know doesn't work:

  +101        $used{"FOO123Z"} = 1;
..snip..
  +323        my $new="FOO123Z";
  +324        my $len = length($new);
  +325        while ( defined $used{$new} && $len > 0 ){  ## Keep the 
+first character the same
  +326          foreach my $c (("A" .. "Z"), 0..9){
  +327            $new =~ s/(.{$len}).(.*)/${1}${c}${2}/ if defined $u
+sed{$new};
  +328          }
  +329          $len-- if defined $used{$new} ;
  +330        }
  +331        $used{$new} = 1;
[download]

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Re: Increment a mixed alphanumeric (Updated) by BrowserUk (Patriarch) on Oct 27, 2015 at 14:18 UTC
So, what should FOO123Z increment to? Showing a sequence of increments would be good. Does this come close to your intent?: `#! perl -slw use strict; my $id = "F00123Z"; for ( 1 .. 11 ) { print $id; substr( $id, 1, -1 )++; } __END__ C:\test>junk72 F00123Z F00124Z F00125Z F00126Z F00127Z F00128Z F00129Z F00130Z F00131Z F00132Z F00133Z` [download] Update: Or maybe this comes closer?: `#! perl -slw use strict; my $id = "F00123Z"; for ( 1 .. 29 ) { print $id; if( substr( $id, -1 ) eq 'Z' ) { substr( $id, -1 ) = 'A'; substr( $id, 1, -1 )++; } else { substr( $id, -1 ) ++; } } __END__ C:\test>junk72 F00123Z F00124A F00124B F00124C F00124D F00124E F00124F F00124G F00124H F00124I F00124J F00124K F00124L F00124M F00124N F00124O F00124P F00124Q F00124R F00124S F00124T F00124U F00124V F00124W F00124X F00124Y F00124Z F00125A F00125B` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". I knew I was on the right track :) In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^2: Increment a mixed alphanumeric (Updated) by miketosh (Acolyte) on Oct 27, 2015 at 14:56 UTC
Right, here is a regexp for valid formats: `/^[A-Z]+[0-9][A-Z]/;` [download] N1234Z becomes N12350 N12359 becomes N1235A N9999Z becomes NA0000 Ordering of the addition is less important than testing all possible variations. Technically NA0000 is invalid since it has a number, but the number part equals zero. I can handle that logic outside of this code construct.	[reply] [d/l]
Re^3: Increment a mixed alphanumeric (Updated) by BrowserUk (Patriarch) on Oct 27, 2015 at 15:38 UTC
By extension: `#! perl -slw use strict; =comment N1234Z becomes N12350 N12359 becomes N1235A N9999Z becomes NA0000 =cut my $id = "F00123Z"; for ( 1 .. 80 ) { print $id; last if substr( $id, -5 ) eq '9999Z'; if( substr( $id, -1 ) eq 'Z' ) { substr( $id, -1 ) = '0'; substr( $id, 1, -1 )++; } elsif( substr( $id, -1 ) eq '9' ) { substr( $id, -1 ) = 'A'; } else { substr( $id, -1 ) ++; } }` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". I knew I was on the right track :) In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]