anchor.diff:          result && x.consume_WhiteSpace ()
   
       member x.tryParse_Eos () : bool =
  -      if x.eos then
  -        true
  -      else
  -        v.Expected (pos, Tokens.EOS)
  -        false
  +      x.eos || (v.Expected (pos, Tokens.EOS); false)
   
     [<AbstractClass>]
     [<NoEquality>]
  
positive.code:       else
          let sr  = r <<< 4
          let   c = x.ch
          if    c >= '0' && c <= '9'  then x.adv () ; x.tryParse_UnicodeChar (n - 1, sr + (int c - int '0'))
          elif  c >= 'A' && c <= 'F'  then x.adv () ; x.tryParse_UnicodeChar (n - 1, sr + (int c - int 'A' + 10))
          elif  c >= 'a' && c <= 'f'  then x.adv () ; x.tryParse_UnicodeChar (n - 1, sr + (int c - int 'a' + 10))
          else
  
negative.code:       if x.eos then x.raise_Digit () || x.raise_Eos () || not first
        else
          let c = x.ch
          if isDigit c then
            x.adv ()
            r <- 10.0*r + (float c - z)
            x.tryParse_UInt (false, &r)
  