Dear monks, I am a Perl newbie and I would like to kindly ask for the help of experts to write a code snippet for my research project in order to parse some text files.
The task:
I have some ranges like the following:
5-10,14-18,22-27 and a string that I have transformed into a series of characters like so: 
1-2-3-4-5-6-7-8-...30

[download]
(not all strings are of the same length of course)
Now, what I need to do for my analysis is two things:

1. substitute the numbers that belong to the ranges with a character, say X. So, instead of 5-6-7-8-9-10 for instance, I will have X-X-X-X-X-X This I have managed to do

2. Starting with a specific character, say A from the beginning (in this case 1), substitute the remaining numbers, interchangably with A and B, when they are separated by a group of X's. For instance, I would do A-A-A-A (instead of 1-2-3-4) until I find 5 where the X's begin and then B-B-B (instead of 11-12-13) and then A-A-A instead of 19-20-21 and, finally B-B-B instead of 28-29-30.


The initial string is then: 
1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20-21-22-23-24-25-26-2
+7-28-29-30

[download]

and the expected one is: 
A-A-A-A-X-X-X-X-X-X-B-B-B-X-X-X-X-X-A-A-A-X-X-X-X-X-X-B-B-B

[download]

Can you please help me with the second point that I cannot solve?

In reply to Help making this substitutions on a strin by Anonymous Monk

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