In Japanese, there are several different ways of expressing conditionality. For example, "[past tense verb ending in -ta] + ra" is one: "sore wo tabetara, byouki ni naru" = "If you eat that, you'll get sick." Another is "[plain form of verb] + to," as in: "sore wo taberu-to, byouki ni naru." The latter form always made sense to me because "-to" is also the Japanese word for "and." But at the same time, I was aware that this connection doesn't really make sense and I wasn't sure why it seemed to help me remember the conditional form.

I think today I realized why the connection exists in my head. It's related to a programming technique common in perl and bash shell scripting. Both of those programming languages implement short-circuit evaluation of conditional statements. That means that, supposing you have a perl statement such as:

if ( ($x == 1) && ($y > 2) )  print "omgwtfbbq!!!11";

The if statement will only evaluate as true if both conditions are true — the variable named $x is equal to 1, and the variable named $y is greater than 2. Thus, if the interpreter determines that $x is not equal to 1, it doesn't need to waste any time evaluating the other side of the && to determine the value of $y, because the statement as a whole is already known to be false. In this case, comparing $y to 2 is a minor calculation, but if each condition of the if were instead a computationally intensive function call, the advantage of not needing to execute the second function call at all could be significant.

Perl programmers often take advantage of short-circuit evaluation somewhat counterintuitively, to write more succinct code (Perl has a reputation for producing nearly unreadable code, but that's not perl's fault; it's the fault of perl programmers). Rather than writing a nice, legible statement such as:

if ($x < 0)  $message = "Invalid value.";

You'll often find the same logic expressed like this:

$x < 0 && $message = "Invalid value.";

They are functionally identical — if $x is not less than 0, the interpreter will not evaluate the other side of the &&, and the text will not be assigned to the $message variable. And it did save two or three bytes of code, which wins you an equivalent number of geek scene points. But it's little tricks like this that contribute to the illegibility of typical perl code.

However, it is awesome to be able to say:

speak() or die;

Anyway, note how the succinct form of the example above looks a lot like the Japanese use of "and" as a way of expressing the concept that "if the one on the left is true, then I'm declaring that the one on the right is true as well." Although that sounds more like mathematical implication than intersection.

God. Japanese, perl, and binary arithmetic. I have friends who are interested in each of those three things, but I suspect that the Venn diagram of the three circles intersects at a single point, named Dan. :)