seriously complicated regular expression in XQuery

jsoniq-regexp-crazy.xq

(: taken from http://markmail.org/message/5p3uespuxk4ew7fa :) 

let $regexp := '(\{)|(\})|(\[)|(\])|(:)|(,)|(true)|(false)|(null)|(\s+)|("([^"\\]|\\"|\\\\|\\/|\\b|\\f|\\n|\\r|\\t|\\u[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9])*")|(-?(0|[1-9][0-9]*)(\.[0-9]+)?([eE][+-]?[0-9]+)?)'
return

let $json := '{
  "firstName": "John",
  "lastName": "Smith",
  "address": {
    "streetAddress": "21 2nd Street",
    "city": "New York",
    "state": "NY",
    "postalCode": 10021
  },
  "phoneNumbers": [
    "212 732-1234",
    "646 123-4567"
  ]
}'
return analyze-string($json, $regexp)