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Program Repair Shop

37

Encapsulate common operations

        $a1->add_observer($g1);
        $a1->add_observer($g1);

• I don't know what the "right" thing is here

• Particularly in conjunction with deletions, etc.

• So I'll just try to get it to be consistent:

• Each unique observer is notified exactly once

• This will come in handy:

        sub _uniq {
          my %seen;
          return grep !$seen{$_}++, @_;
        }

• Now let's dive into the code.

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