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  1. #!/usr/bin/perl
  2. # your code goes here
  3.  
  4. sub makeIteratorClass {
  5.         my ($f) = @_;
  6.  
  7.         sub gensym {
  8.                 my @chars = ("A".."Z", "a".."z");
  9.                 my $string;
  10.                 $string .= $chars[rand @chars] for 1..8;
  11.                 return $string;
  12.         };
  13.  
  14.         return sub {
  15.                 my ($iv) = @_;
  16.  
  17.                 my $self = { iv => $iv };
  18.                 my $sym = gensym();
  19.                 *{ "$sym" . "::getNext" } = sub {
  20.                         my ($self) = @_;
  21.                         $self->{iv} = $f->($self->{iv});
  22.                         return $self->{iv};
  23.                 };
  24.                 bless $self, $sym;
  25.                 return $self;
  26.         }
  27. }
  28.  
  29. my $plusOner = makeIteratorClass(sub { my ($x) = @_; $x + 1 });
  30. my $o = $plusOner->(5);
  31. print $o->getNext();
  32. print $o->getNext();
  33. print $o->getNext();
Success #stdin #stdout 0s 3564KB
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https://ideone.com/e5eMfh
language:
Perl (perl 5.28.1)
created:
10 years ago
visibility:
public

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