A co-worker is fond of saying, “You have a problem so you solve it with a regular expression. Now you have two problems.”<\/p>\n
Regular expressions are powerful tools but they can easily cause unforeseen complications. The script I’ve been trying to improve contains a section for stripping HTML. It uses HTML::Strip<\/a> to do this but does a lot of pre- and post-processing with a series of regular expressions. If the script was run with the stripping feature enabled an extra 21 minutes to the running time. You can imagine how quickly that adds up.<\/p>\n Looking at the regexes I was able to easily tweak them a bunch of them. Some I was able to combine through the use of classes, some I removed unnecessary groupings. At the end I’d reduced the processing time by about 8 1\/2 minutes. I’m not completely celebrating yet as I’m still working on verifying the new data, but currently all the expected IDs are in place and things look good.<\/p>\n 13 minutes is still a lengthy processing time, but it’s a big improvement and I think I may still be able to whittle it down. While I spotted numerous issues with the old regexes, I did actually learn a couple things while doing this. Regular Expressions are far more complex than they seem at first and it’s very worthwhile to familiarize yourself with how they work. The perlre<\/a> section at perldoc.perl.org<\/a> is a wonderful resource but before trying to absorbing it all I’d look for a primer. Robert’s Perl Tutorial<\/a> has an excellent section on regular expressions. For a more pointed document, Steve Litt’s Perl Regular Expressions<\/a> is the top Google result and looks quite good.<\/p>\n","protected":false},"excerpt":{"rendered":" A co-worker is fond of saying, “You have a problem so you solve it with a regular expression. Now you have two problems.” Regular expressions are powerful tools but they can easily cause unforeseen complications. The script I’ve been trying to improve contains a section for stripping HTML. It uses HTML::Strip to do this but […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,3],"tags":[11],"class_list":["post-17","post","type-post","status-publish","format-standard","hentry","category-legacy-issues","category-perl","tag-regex"],"_links":{"self":[{"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/posts\/17","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/comments?post=17"}],"version-history":[{"count":1,"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/posts\/17\/revisions"}],"predecessor-version":[{"id":18,"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/posts\/17\/revisions\/18"}],"wp:attachment":[{"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/media?parent=17"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/categories?post=17"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dotcomdotat.com\/blog\/wp-json\/wp\/v2\/tags?post=17"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}