Re: Stupid mistakes I repeatedly make

I some times fall for the my ($self, $bar, $baz) = shift; bug, but there is another bug that catches me, especially when I start to consciously think about it instead of letting my fingers interpret my commands:

  my $foo = 'bar';
  $foo ~= s/a/ee/;
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Of course, this is the reversed regex operator (which doesn't exist), and Perl sees this as a syntax error. ambrus taught me a good mnenonic - the negated comparison for the regex binding operator is !~, which has the same order as !=, and thus, the regex binding operator must be =~.

In a certain way this confusion when thinking about what my fingers should be doing reminds me of the problem that octopodes have when coordinating their arms, which, seemingly, they never do - they just send commands to them and then verify the behaviour by optical inspection.

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Re^2: Stupid mistakes I repeatedly make by demerphq (Chancellor) on Mar 27, 2005 at 18:39 UTC
ambrus taught me a good mnenonic - the negated comparison for the regex binding operator is !~, which has the same order as !=, and thus, the regex binding operator must be =~. I use the same mnemonic but word it a bit differently: I tend to translate $a == $b to "a is b", so I translate $a =~ /Pattern/ as "a is like Pattern", and since ! is traditionally "not" I translate $a !~/Pattern/ as "a not like Pattern". Thus the "=~" operator to me is the "is like" operator and the "!~" operator is the "not like" operator. --- demerphq	[reply]
Re^2: Stupid mistakes I repeatedly make by merlyn (Sage) on Mar 27, 2005 at 18:53 UTC
After years of teaching "Learning Perl" in classrooms, and saying "equal tilde", "equal tilde" over and over again, it's hard to get it wrong. -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply]
Re^3: Stupid mistakes I repeatedly make by brian_d_foy (Abbot) on Mar 28, 2005 at 02:00 UTC
Teaching is a great way to get paid to say something over and over again so you don't ever forget it. Sadly, there are only four days in our Learning Perl course, and we even say in the first fifteen minutes that we can't teach everything in a week. :) -- brian d foy <brian@stonehenge.com>	[reply]
Re^2: Stupid mistakes I repeatedly make by jplindstrom (Monsignor) on Mar 27, 2005 at 18:31 UTC
Heh, I used to do the same thing occasionally as a newbie, and overcame it the exact same way :) /J	[reply]


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