Comments on: How to google for &&=

Question: How to google for &&=

arrhn — Mon, 28 Apr 2008 17:56:06 -0800

How do I find the answer to "what does &&= do in Perl?" via Google?

I'm not looking for what &&= does. I'm looking for how to find it on Google. Thank you.

By: nev

nev — Mon, 28 Apr 2008 17:58:48 -0800

I'm pretty sure only Google Code Search supports character-based searching like that (and regular expressions!)

By: pompomtom

pompomtom — Mon, 28 Apr 2008 18:00:32 -0800

Stick it in quotes:

eg or

By: winston

winston — Mon, 28 Apr 2008 18:00:42 -0800

Googling "perl operators" did it for me.

If that didn't work, I would have tried "list of perl operators."

If I hadn't known they were called operators, I would have tried "perl manual" or "perl dictionary" or "perl reference," looking for something that listed everything perl does, hopefully in an easy-to-navigate fashion that would help me find the part I'm looking for quickly.

By: burnmp3s

burnmp3s — Mon, 28 Apr 2008 18:10:07 -0800

Stick it in quotes

It looks like Google can do the && part fine, but it doesn't seem to recognize the = part. For example, += (a very common operator) generates zero results.

Perl is an annoying language for trying to look up things like that, because it uses tons of special characters for everything. For example, I defy anyone to figure out what most of the Perl Golf winners are actually doing by looking up each part in Google. I guess it's better than APL though.

By: Flunkie

Flunkie — Mon, 28 Apr 2008 18:12:28 -0800

I think the poster is asking for a direct way to search for something like &&=, not an indirect way to find this particular example (such as "google for perl operators").

Assuming that I'm correct, the answer is: You don't.

Suggestions such as pompomtom's "put it in quotes" are not accurate. When you ask google for "&&=", it actually gives you the results for "&&". That is, it ignores the equals sign. This is the same as if you didn't put it in quotes in the first place.

According to Google's help page on punctuation:

Google doesn't recognize special characters such as exclamation points, question marks, or the @ sign. These types of characters are so common that including them in a search would greatly slow the delivery of the search results. (...) we don't currently offer a way to force Google to recognize all special characters

They don't explicitly say that the equals sign is included in this list of characters that they don't support, but it sure seems to be.

By: kcm

kcm — Mon, 28 Apr 2008 18:28:01 -0800

man perlop

By: blacklite

blacklite — Mon, 28 Apr 2008 18:49:27 -0800

No one really has any idea what Google does internally, but if their implementations are anything like the academic community's ideas about indexing, they deliberately ignore various punctuation characters to, as their help page says, improve speed. The characters literally are not in the indexes -- they're still there in the full text, of course, as you can see in cached copies; they keep everything -- but they would, theoretically anyhow, limit the amount of text that gets indexed as much as possible. When you have the entire internet to index, every character you can leave out helps, since they seem to (according to Alexa + some math) get 2.8 billion searches per day from ~395 million users.

(Or put another way, each character on their front page = a terabyte downloaded each year... which isn't actually relevant to the question but it's an awesome number...)

By: arrhn

arrhn — Mon, 28 Apr 2008 20:08:50 -0800

Not that it matters, but incidentally, googling perl operators and/or checking the perlop page also don't actually tell you what ||= or &&= do. :-)

By: arrhn

arrhn — Mon, 28 Apr 2008 20:14:38 -0800

Whoops. I take it back. Perl op does indeed list it.

By: dws

dws — Mon, 28 Apr 2008 23:08:08 -0800

My first thought was to Google for "perl operators". The fifth hit was the abovementioned perlop - Perl operators and precedence.