class BigDecimal

d.to_digits # => "3.14"
d = BigDecimal("3.14")

require 'bigdecimal/util'

This method is deprecated; use BigDecimal#to_s("F") instead.
Converts a BigDecimal to a String of the form "nnnnnn.mmm".

a.to_digits -> string
call-seq:

def to_digits
  if self.nan? || self.infinite? || self.zero?
    self.to_s
  else
    i       = self.to_i.to_s
    _,f,_,z = self.frac.split
    i + "." + ("0"*(-z)) + f
  end
end