正则表达式

RegExp

• flavor
  • PCRE - Perl Compatible Regular Expressions
    • PostgreSQL
  • PCRE2 - 2017
    • PHP >= 7.3
    • jit, stack memory -> heap memory mgmt
  • re2
    • google/re2/wiki/Syntax
  • js
    • v8 Irregexp
    • mdn Regular expressions
  • java
  • .net
  • python
• golang
  • RE2
  • dlclark/regexp2
    • full-featured regex engine in pure Go based on the .NET engine
• tools
  • regex101.com
  • www.regexpal.com
  • regexr.com
  • www.debuggex.com
  • regexbuddy.com
    • Windows 应用
  • extendsclass.com/regex-tester.html
    • Visualizer
  • www.regexplanet.com/advanced/java/index.html
  • www.regextester.com
• 参考
  • slevithan/awesome-regex
  • RegexNote
  • wikipedia Regular expression
  • www.regular-expressions.info
  • Tempered Greedy Token stackoverflow.com/a/37343088/1870054
  • benhoyt.com/writings/rob-pike-regex Rob Pike’s simple C regex matcher in Go
    • HN
  • slevithan/regex
    • 使用 regex 定义的 jinja 解析 davidodenwald/prettier-plugin-jinja-template/src/regex_editable.ts

// https://www.noulakaz.net/2007/03/18/a-regular-expression-to-check-for-prime-numbers/
// https://news.ycombinator.com/item?id=30564287
const isPrime = (n) => !/^1?$|^(11+?)\1+$/.test('1'.repeat(n));

// https://stackoverflow.com/a/201378/1870054
const emailFull =
  /(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]))\.){3}(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9])|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])/;
const emailSimple = /^[^\s@]+@([^\s@.,]+\.)+[^\s@.,]{2,}$/;
// http://www.w3.org/TR/html5/forms.html#valid-e-mail-address
const emailW3c =
  /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;

// 反匹配 - 除了给的不匹配其他都匹配
const notThis = /^(?:(?!this).)*$/;
// py, java ^(.(?!(some text)))*$
// pcre ^(?:(?!abc|xyz).)*$

• escaped string - 匹配 'I\'am'
  • (["'])((?:(?=(?:\\)*)\\.|.)*?)\1
  • regex101.com/r/mS1zJ8

• XHXIAIEIN/split-string-address
• GrapecityXian/PhoneCommand

JavaScript

• flags
  • i - ignoreCase
  • m - multiline
  • s - dotAll
  • g - global
  • y - sticky
  • d - hasIndices
  • u - unicode
  • v - unicodeSets
• atoms - 正则最基础单元
• \c[A-Za-z]
  • 控制字符
  • = char % 32
  • 因为大写和小写相差 32 因此 \cJ 和 \cj 是一样的
  • \cJ = \n
• replacement - 替换
  • $$ -> $
  • $&
  • `$``
  • $'
  • $<n>
  • replacer(match,p1,p2,offset,wholeString,namedGroups)
• /u -> unicode
  • 影响 \w, \u{HHHH}, \uHHHH
  • /[\p{L}\p{N}]+/u
• RegExp /v, unicodeSets
  • /^\p{RGI_Emoji}$/v.test('😵‍💫')=true - Unicode string properties
  • /^[\q{😵‍💫}]$/v.test('😵‍💫')=true - \q for String literals
  • /^[\p{RGI_Emoji}--\q{😵‍💫}]$/v.test('😵‍💫')=false - 支持排除
• 参考
  • Regular expressions

re2

• google/re2/wiki/Syntax

不支持

CJK

const reCJK = /[\p{Unified_Ideograph}\u3006\u3007][\ufe00-\ufe0f\u{e0100}-\u{e01ef}]?/;
const reChinese = /[\u4e00-\u9fa5]/;

• ayaka.shn.hk/hanregex