Brian Friesen’s talk on Regular Expressions was probably my favorite of the conference. You gotta admire a guy who builds a regular expression engine to properly demo and train folks up on the ‘devil’s language’ (as I and others I’ve known have called it)… Folks that hate regex and those that live and breathe the stuff all got something from the session. Good stuff.<\/p>\n
Brian Friesen Works at Quicken Loans (side note, I used QL last year – hands down the best UX I’ve ever seen in a mortgage product\/service)<\/p>\n github.com\/QuickenLoans\/RegExpose<\/a><\/p>\n Regexper.com<\/a><\/p>\n Regular-expressions.info<\/a><\/p>\n The Bible:<\/strong> 1. RegEx are hierarchical<\/strong><\/p>\n Root node = the whole expression<\/p>\n ABC would tree out like this:<\/p>\n ABC – root 2. RegEx do their thing sequentially<\/strong><\/p>\n A RegEx will match if each of its child nodes matches in sequence RegEx are by default case-sensitive<\/strong><\/p>\n Character classes are surrounded by square brackets<\/strong> Shorthand matches<\/strong> Alternation<\/strong> | character means “or” Quantifiers (quantifiers are always AFTER)<\/strong> Greedy Quantifiers<\/strong> (greedy means quantifier always wants more, ie. will keep going) Ultimate lazy quantifier: .*<\/p>\n Causion against using “*.” – can lead to a match failing since the greedy ‘any character as many as possible’ matching could lead to skipping more specific matches after the *.<\/p>\n Lazy Quantifiers <\/strong>– will only match as much as is needed, without going overboard – ab.*?cd would match “abc12345cd” with the lazy quantifier returning to the ‘c’ character repeatedly before going back to the next number character<\/p>\n More alternation<\/strong> Quantifers + grouping<\/strong> Brian Friesen’s talk on Regular Expressions was probably my favorite of the conference. You gotta admire a guy who builds a regular expression engine to properly demo and train folks up on the ‘devil’s language’ (as I and others I’ve known have called it)… Folks that hate regex and those that live and breathe the … Continue reading Notes from CodeStock 2014\u2032s \u201cRegular Expressions\u201d presentation<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4,17],"tags":[48,45,46,47,43,44],"_links":{"self":[{"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/posts\/194"}],"collection":[{"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/comments?post=194"}],"version-history":[{"count":2,"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/posts\/194\/revisions"}],"predecessor-version":[{"id":196,"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/posts\/194\/revisions\/196"}],"wp:attachment":[{"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/media?parent=194"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/categories?post=194"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.minotaurdesign.com\/blog\/wp-json\/wp\/v2\/tags?post=194"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n@brianfriesen<\/a><\/p>\n
\nMastering Regular Expressions<\/em> by Jeffery Friedl
\n– can read the first 2\/5 of the book and you have enough
\n———————————————————————–<\/p>\n
\nA – character literal
\nB – character literal
\nC – character literal<\/p>\n
\nAfter a match, the RegEx engine will continue trying to find further matches until it has covered the entire string.<\/p>\n
\n– for a range, use a dash.
\n– if you need a dash in the match, put it at the beginning of your set within square brackets
\n– you can also include specific characters or numbers to match against
\n– can include a-z and A-Z, or you can pass an additional param to ignore case
\n– a negated character class = add a “^” carat character before a match. ie [^a-f0-9] would ignore a-f<\/p>\n
\n– \\d is the same as [0-9]
\n– \\D is the same as [^0-9]
\n– \\s matches whitespace chars
\n– \\w is the same as any word character, meaning [A-Za-z0-9_]
\n– . matches any character, depending on options (ie except for new line character)<\/p>\n
\n(it’s a pipe dream)<\/p>\n
\n– linos|tigers|bears ‘lions’ would match, but regExp doesn’t know if its the BEST match, so it saves state (a breadcrumb) and moves to check the other choices.
\n– if a match hits on the last option in a set of choices, no state will be saved, no breadcrumbs etc.<\/p>\n
\n(Because sometimes, quantity trumps quality)<\/p>\n
\n——————
\n– ? = optional
\n– * = will match zero, will match many
\n– PO*P would match “PP” as well as “POOP”
\n– + = must match at least once to succeed
\n– NO+! would match “NO!” as well as “NOOOOOOOOOOO!”
\n– {} = match a specific number of things
\n– \\d{3} = this means match exactly 3 digits
\n– \\d{3,15} = this means match at least 3, but up to 15
\n– \\d{3,} = this means match at least 3 with no high end limit<\/p>\n
\nOnce a match is made it will pass control to the next match paramater until it’s needed again…
\n—————-
\n.*? = Lazy
\n{3,5}? = also Lazy (in this case, once 3 digits were matched, the next node in regexp would be matched)<\/p>\n
\n—————-
\n(?:white|dog|brick) house
\n– match against “dog house”<\/p>\n
\n———————
\n(?:NaN)+
\n– match against “NaNNaNNaNNaNNaN”<\/p>\n","protected":false},"excerpt":{"rendered":"