Hi Monks,
so, I am new to Perl and currently trying to play around with some small tasks in order to improve my skills...
I am now learning regular expressions and I am stuck with this issue:
Imagine that you have a line like the following:
------BBBBB-----------------------------------------------------------
+-------------------------------------------------BBBBBB----BBBBBBBB--
+---------------BBBBBB------------------------------------------------
+--------BBBBBBB---------------BBBBB-----BBBBBBBBB--------------------
+----------------BBBBBBBBB------BBBBBBBBB----------------------------B
+BBBBBBBB--------------------------------------BBBBBBBB-------BBBBBB--
+-------------------BBBBBBB--------------------------BBBBBBBB----

[download]

and you want to transform it to:
iiiiiiMMMMMooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooooMMMMMMiiiiMMMMMMMMoo
+oooooooooooooooMMMMMMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
+iiiiiiiiMMMMMMMoooooooooooooooMMMMMiiiiiMMMMMMMMMoooooooooooooooooooo
+ooooooooooooooooMMMMMMMMMiiiiiiMMMMMMMMMooooooooooooooooooooooooooooM
+MMMMMMMMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiMMMMMMMMoooooooMMMMMMii
+iiiiiiiiiiiiiiiiiiiMMMMMMMooooooooooooooooooooooooooMMMMMMMMiiii

[download]

, which, in practical terms means: replace all B's with M's and, as far as the - are concerned, start with i and then alternate between i and o on the two sides of the M parts. The B -> M replacement of course is trivial to do and I could also say that if you find ---- in the beginning of the line, replace them with iiii...But I am not sure how to do the alternation thing!
Can you help me on this a bit?

In reply to Tips on how to perform this substitution? by Anonymous Monk

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