Good rule of thumb: whenever you think "lookup table", your next thought should be "use a hash". 

my (@list, %find);
@list = qw/a t g c/;
# You can do it manually...
@find{@list} = qw/t a c g/;
# ...or programmatically:
@find{@list} = map {reverse @list[$_*2, $_*2+1] } 0..@list/2-1;

print "$_: $find{$_}\n" for @list;

[download]

Output: 

a: t
t: a
g: c
c: g

[download]

--
"Language shapes the way we think, and determines what we can think about."
-- B. L. Whorf

In reply to Re: char substitution without regexes by oko1
in thread char substitution without regexes by biohisham

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