Yes, maybe it works, but I can't comment much on it without having seen the data, which you haven't shown yet.
One thing, though: if you need an atom or a sub-pattern once and only once, then you don't need a quantifier such as {1}, that's what the regex engine will do anyway by default. So that this slightly simpler substitution should do the same thing:
$loop_variable =~ s/ ?[A-Za-z] (\[(.*)\])? ?\d+(.*)?\.+(.*)?//g;
I believe the rest of the regex could probably be improved. For example something like
.* is rarely a good idea (
.*? is often better), and
(\[(.*)\])? is probably better written as
(\[(.*?)\])? or as
(\[[^]]*\])? (untested). That's just one example.
But I would need to see the data and to know what exactly you find significant in the strings you are trying to match (what are the invariants that you are looking for and what are the variable parts) before I could really give more informed advice.
