Hi all!
I have a string :
$seq="IIIIIMMMMMMMMMMMOOOOOOOOOOOOOOOOMMMMMMMMMMMMMIIIIIMMMMMMMMMOOOOO
+OOOOOOOOOMMMMMMMMMMMMMIIIMMMMMMMMMMMOOOOOOOOOOOOOOOMMMMMMMMMMMIIIIIIM
+MMMMMMMMMMMMOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMIIIMMMMMMMMMOOOOOOOOOOOOOOO
+OOOOOOOOOOOOMMMMMMMIIIIMMMMMMMMMMMOOOOOOOOOOOOOOOOOOOOOMMMMMMMIIIMMMM
+MMMMMOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMIIIMMMMMMMMMMMOOOOOOOOOOOOOOOO
+OMMMMMMMMI";

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and I want to find all groups of MMMMMM. I don't want to find only every position in the string that has 'M', i.e. pos6, pos7, pos8, pos9 etc but I want to have something like:
1st group : pos 7-15
2nd group : pos 23-34
3rd group : pos 45-55
etc
How can this be done?

In reply to 'grouping' substrings? by Anonymous Monk

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