Re: Re: Re: A most obscure bug

The automatic implied defined() was added after my time as pumpking. When I discovered the danger of while (<>) {}, I didn't feel I could change the language without breaking things, so I added a warning instead. That warning was unsatisfactory to a lot of people, so the issue came up again, this time during one of Larry's more available periods. Somebody proposed the language change we have today, Larry OK'd it, and the patch was installed almost immediately.

-- Chip Salzenberg, Free-Floating Agent of Chaos

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Re4: A most obscure bug by blakem (Monsignor) on Dec 20, 2001 at 00:32 UTC
Interestingly, your warning is still in effect. The only way I can throw it is through this bug: `# OK, gets implied defined(), no warning, correct output % perl -lwe 'print while glob("{dog,cat,0,pig,cow}")' dog cat 0 pig cow # Buggy, no implied defined(), throws warning and misbehaves % perl -lwe 'print while $_ = glob("{dog,cat,0,pig,cow}")' Value of glob construct can be "0"; test with defined() at -e line 1 +. dog cat` [download] -Blake	[reply] [d/l]

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Re4: A most obscure bug
by blakem (Monsignor) on Dec 20, 2001 at 00:32 UTC

# OK, gets implied defined(), no warning, correct output
% perl -lwe 'print while glob("{dog,cat,0,pig,cow}")'

  dog
  cat
  0
  pig
  cow


# Buggy, no implied defined(), throws warning and misbehaves
% perl -lwe 'print while $_ = glob("{dog,cat,0,pig,cow}")'

  Value of glob construct can be "0"; test with defined() at -e line 1
+.
  dog
  cat
[download]

-Blake

[reply]
[d/l]