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Quick questions: multi submethod and undef.method

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Ingo Blechschmidt
June 5, 2005 13:25
Quick questions: multi submethod and undef.method
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two quick questions:

Are multi submethods allowed?

  my $x = undef;
  my $y = $x.some_method;
  # $y now contains an unthrown exception object, saying that undef
  # doesn't .can("some_method"), right?
  say $y; # Only now it dies, correct?

This is important if you have a sub which may either return a custom
object or undef:
  my $x = sub_which_returns_an_object_or_undef();
  my $y = $x.some_method;

One builtin example is "caller":
  my $x = caller(5555);  # undef if there's no such stack frame
  my $y = $x.line;       # unthrown exception object


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