1. Lookbehind in JS regular expressions

    The positive lookbehind (`(?<= )`) and negative lookbehind (`(?<! )`) zero-width assertions in JavaScript regular expressions can be used to ensure a pattern is preceded by another pattern.

  2. css at-rule: `@document`: `regexp()`

  3. javascript built-in: regexp

  4. javascript built-in: regexp: @@match

  5. javascript built-in: regexp: @@matchall

  6. javascript built-in: regexp: @@replace

  7. javascript built-in: regexp: @@search

  8. javascript built-in: regexp: @@species

  9. javascript built-in: regexp: @@split

  10. javascript built-in: regexp: compile

  11. javascript built-in: regexp: dotall

  12. javascript built-in: regexp: exec

  13. javascript built-in: regexp: flags

  14. javascript built-in: regexp: global

  15. javascript built-in: regexp: global: prototype accessor property (es2015)

  16. javascript built-in: regexp: hasindices

  17. javascript built-in: regexp: ignorecase

  18. javascript built-in: regexp: ignorecase: prototype accessor property (es2015)

  19. javascript built-in: regexp: `regexp.input` (`$_`)

  20. javascript built-in: regexp: lastindex

  21. javascript built-in: regexp: `regexp.lastmatch` (`$&`)

  22. javascript built-in: regexp: `regexp.lastparen` (`$+`)

  23. javascript built-in: regexp: `regexp.leftcontext` (`$``)

  24. javascript built-in: regexp: multiline

  25. javascript built-in: regexp: multiline: prototype accessor property (es2015)

  26. javascript built-in: regexp: `regexp.$1-$9`

  27. javascript built-in: regexp: named capture groups

  28. javascript built-in: regexp: unicode property escapes (`\p{...}`)

  29. javascript built-in: regexp: `regexp()` constructor

  30. javascript built-in: regexp: `regexp.rightcontext` (`$'`)

  31. javascript built-in: regexp: source

  32. javascript built-in: regexp: source: "(?:)" for empty regexps

  33. javascript built-in: regexp: source: escaping

  34. javascript built-in: regexp: source: prototype accessor property (es2015)

  35. javascript built-in: regexp: sticky

  36. javascript built-in: regexp: sticky: anchored sticky flag behavior per es2015

  37. javascript built-in: regexp: sticky: prototype accessor property (es2015)

  38. javascript built-in: regexp: test

  39. javascript built-in: regexp: tosource

  40. javascript built-in: regexp: tostring

  41. javascript built-in: regexp: tostring: escaping

  42. javascript built-in: regexp: unicode

  43. lookahead assertions in js regular expressions