Re^2: How to introduce a frustrating bug with a single whitespace

Yes, but at least that gets caught with warnings (or -w):

$ perl -we 'print (4+5)*20;'
print (...) interpreted as function at -e line 1.
Useless use of multiplication (*) in void context at -e line 1.
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The whitespace bug described in the original node is the first bug I've had in a while that:

wasn't caught by syntax checking (it's valid Perl)
wasn't griped about with strict and warnings on
wasn't a design error

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Comment on Re^2: How to introduce a frustrating bug with a single whitespace Download Code

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Re^3: How to introduce a frustrating bug with a single whitespace by TimToady (Parson) on Dec 24, 2007 at 22:05 UTC
Well, it's kind of you to say that, but given the fact that Perl 6 changed `=~` to `~~`, it arguably was a design error. (Though this particular failure mode is not why it was changed, but rather the failure of reversing the operator to say `~=` instead. It doesn't matter if you reverse `~~`.) Anyway, if you split `~~` in Perl 6 with whitespace, it'll parse, but will likely give you a "useless use of `~` in void context" warning. By the way, Perl 6 also fixes the "`print (4+5)*20`" faq...	[reply] [d/l] [select]
complex data structure typo (was Re^3: How to introduce a frustrating bug with a single whitespace) by doom (Deacon) on Dec 31, 2007 at 02:30 UTC
The whitespace bug described in the original node is the first bug I've had in a while that: wasn't caught by syntax checking (it's valid Perl) wasn't griped about with strict and warnings on wasn't a design error I've got one of those, though not a whitespace bug. Just recently I was messing with a data-structure that was supposed to be an array of arrays of arrays: `$rect_list = [ [ [0, 0], [3, 9 ] ], [ [5, 4], [3, 10] ], [ [7, 8], [9, 11] ]. [ [2, 4], [5, 15] ], [ [1, 9], [9, 13] ], ];` [download] First question: Can you spot the bug? Second question: Do you know what it does?	[reply] [d/l]
Re: complex data structure typo (was Re^3: How to introduce a frustrating bug with a single whitespace) by bobf (Monsignor) on Dec 31, 2007 at 02:44 UTC
Tricky. ;-) <Reveal this spoiler or all in this thread>	[reply] [d/l]


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