in reply to Replace characters within string

After a quick search, these threads seem to have discussions related to the problem of the current thread:

I recall seeing this type of problem, which seems vaguely bioinformatical, discussed from time to time, but I don't know what the problem is; I don't know what to call it. Can anyone put a name to this thing?

Give a man a fish:  <%-{-{-{-<

In Section Seekers of Perl Wisdom