whitespace_regex.rb

whitespace_chars = [
  "\\u0009", # CHARACTER TABULATION
  "\\u000A", # LINE FEED (LF)
  "\\u000B", # LINE TABULATION
  "\\u000C", # FORM FEED (FF)
  "\\u000D", # CARRIAGE RETURN (CR)
  "\\u0020", # SPACE
  "\\u0085", # NEXT LINE (NEL)
  "\\u00A0", # NO-BREAK SPACE
  "\\u1680", # OGHAM SPACE MARK
  "\\u180E", # MONGOLIAN VOWEL SEPARATOR
  "\\u2000", # EN QUAD
  "\\u2001", # EM QUAD
  "\\u2002", # EN SPACE
  "\\u2003", # EM SPACE
  "\\u2004", # THREE-PER-EM SPACE
  "\\u2005", # FOUR-PER-EM SPACE
  "\\u2006", # SIX-PER-EM SPACE
  "\\u2007", # FIGURE SPACE
  "\\u2008", # PUNCTUATION SPACE
  "\\u2009", # THIN SPACE
  "\\u200A", # HAIR SPACE
  "\\u2028", # LINE SEPARATOR
  "\\u2029", # PARAGRAPH SEPARATOR
  "\\u202F", # NARROW NO-BREAK SPACE
  "\\u205F", # MEDIUM MATHEMATICAL SPACE
  "\\u3000"  # IDEOGRAPHIC SPACE
]

p "[" + whitespace_chars.join("") + "]"