/tools/Ruby/lib/ruby/1.8/bigdecimal/util.rb
http://github.com/agross/netopenspace · Ruby · 65 lines · 40 code · 4 blank · 21 comment · 5 complexity · ab3d25a4e41505d534c3e5950d16219d MD5 · raw file
- #
- # BigDecimal utility library.
- #
- # To use these functions, require 'bigdecimal/util'
- #
- # The following methods are provided to convert other types to BigDecimals:
- #
- # String#to_d -> BigDecimal
- # Float#to_d -> BigDecimal
- # Rational#to_d -> BigDecimal
- #
- # The following method is provided to convert BigDecimals to other types:
- #
- # BigDecimal#to_r -> Rational
- #
- # ----------------------------------------------------------------------
- #
- class Float < Numeric
- def to_d
- BigDecimal(self.to_s)
- end
- end
- class String
- def to_d
- BigDecimal(self)
- end
- end
- class BigDecimal < Numeric
- # Converts a BigDecimal to a String of the form "nnnnnn.mmm".
- # This method is deprecated; use BigDecimal#to_s("F") instead.
- def to_digits
- if self.nan? || self.infinite? || self.zero?
- self.to_s
- else
- i = self.to_i.to_s
- s,f,y,z = self.frac.split
- i + "." + ("0"*(-z)) + f
- end
- end
- # Converts a BigDecimal to a Rational.
- def to_r
- sign,digits,base,power = self.split
- numerator = sign*digits.to_i
- denomi_power = power - digits.size # base is always 10
- if denomi_power < 0
- Rational(numerator,base ** (-denomi_power))
- else
- Rational(numerator * (base ** denomi_power),1)
- end
- end
- end
- class Rational < Numeric
- # Converts a Rational to a BigDecimal
- def to_d(nFig=0)
- num = self.numerator.to_s
- if nFig<=0
- nFig = BigDecimal.double_fig*2+1
- end
- BigDecimal.new(num).div(self.denominator,nFig)
- end
- end