const
  SPACE = #$0020;
  NO_BREAK_SPACE = #$00A0;
  EN_QUAD_SPACE = #$2000; //1 en (= 1/2 em)
  EM_QUAD_SPACE = #$2001; // 1 em (nominally, the height of the font)
  EN_SPACE_SPACE = #$2002; // 1 en (= 1/2 em)
  EM_SPACE_SPACE = #$2003; // 1 em
  THREE_PER_EM_SPACE = #$2004; // 1/3 em
  FOUR_PER_EM_SPACE = #$2005; // 1/4 em
  SIX_PER_EM_SPACE = #$2006; // 1/6 em
  FIGURE_SPACE = #$2007; // “Tabular width”, the width of digits
  PUNCTUATION_SPACE = #$2008; // The width of a period “.”
  THIN_SPACE = #$2009; // 1/5 em (or sometimes 1/6 em)
  HAIR_SPACE = #$200A; // Narrower than THIN SPACE
  ZERO_WIDTH_SPACE = #$200B; //Nominally no width, but may expand
  NARROW_NO_BREAK_SPACE = #$202F; // Narrower than NO-BREAK SPACE (or SPACE)
  MEDIUM_MATHEMATICAL_SPACE = #$205F; // 4/18 em
  IDEOGRAPHIC_SPACE = #$3000; //　The width of ideographic (CJK) characters.
  ZERO_WIDTH_NO_BREAK_SPACE = #$FEFF;
