I was just reminded about this small thing, which is so easy to forget – regular expressions that have markers of line start (^) and\/or line end($) are so much faster than those regexps that don’t have these markers. The thing is that with line start\/end marker regexp engine needs to make only one match\/substution, whereas when there is no such markers, it has to repeat the match\/substitution operation at every character of the string.<\/p>\n
In practice, it’s unbelievable how much difference this can make. Especially when using complex regular expressions over large data sets.<\/p>\n
P.S.: I understand that it is not always possible to use these markers, but I think that they can be used much more often than they are. Everywhere.<\/p>\n\n","protected":false},"excerpt":{"rendered":"\n
I was just reminded about this small thing, which is so easy to forget – regular expressions that have markers of line start (^) and\/or line end($) are so much faster than those regexps that don’t have these markers. The thing is that with line start\/end marker regexp engine needs to make only one match\/substution, … Continue reading RegExp reminder<\/span><\/a><\/p>\n\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false,"_links_to":"","_links_to_target":""},"categories":[1,18],"tags":[246,1057,36,2290,74],"keyring_services":[],"class_list":["post-9930","post","type-post","status-publish","format-standard","hentry","category-general","category-programming","tag-optimization","tag-performance","tag-perl","tag-regular-expressions","tag-tips"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t