November 2002
Intermediate to advanced
758 pages
19h 45m
English
Content preview from Computer Science & Perl ProgrammingBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 16. Nibbling Strings
Jeffrey Friedl
Several months ago I began working at Yahoo!, where I apply my text-processing enthusiasm to financial information and news feeds. You can see the result at http://quote.yahoo.com.
It’s fertile ground for Perl to flex its muscle, but I recently came across a problem that had me stumped until the oft-ignored pos came to the rescue. In this article, we’ll take a look at the problem and at a few different tactics I used trying to solve it. I hope it’ll provide some interesting techniques to help you with similar problems.
The Problem
Because Yahoo! receives articles from various news services, we’d like to link them to the news page for each company mentioned in the article. Sometimes the news services encode information about which companies are referenced, and sometimes not. For these articles, I proposed that we scan the articles for company names.
Easier said than done. Considering that Yahoo! maintains news on over 15,000 companies, think how you might go about identifying the companies mentioned in any particular article. Cycling through each company name to see if it’s present is simple, but would take forever. And one huge /Yahoo|Intel|Adaptec|GeneralMotors|…/ regex to match all company names would also take way too long to run.
Those who are familiar with the different styles of regex engines will recognize that a huge /this|that|other|…/ set of alternates will generally run slowly in Perl, but faster with a tool like lex or flex (which ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.