Eval is avoidable:

{
  my %T = (
    (map {chr() => chr} 0..0377),
    (map {sprintf("%o",$_) => chr} 0..07),
    (map {sprintf("%02o",$_) => chr} 0..077),
    (map {sprintf("%03o",$_) => chr} 0..0377),
    (split //, "r\rn\nb\ba\af\ft\tv\013")
  );

  sub unescape { s/\\([0-7]{1,3}|.)/$T{$1}/g for @_ }
}
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I am saddened no-one plays golf in this Monastery.