/
util.rb
185 lines (169 loc) · 3.89 KB
/
util.rb
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# frozen_string_literal: false
#
#--
# bigdecimal/util extends various native classes to provide the #to_d method,
# and provides BigDecimal#to_d and BigDecimal#to_digits.
#++
require 'bigdecimal'
class Integer < Numeric
# call-seq:
# int.to_d -> bigdecimal
#
# Returns the value of +int+ as a BigDecimal.
#
# require 'bigdecimal'
# require 'bigdecimal/util'
#
# 42.to_d # => 0.42e2
#
# See also Kernel.BigDecimal.
#
def to_d
BigDecimal(self)
end
end
class Float < Numeric
# call-seq:
# float.to_d -> bigdecimal
# float.to_d(precision) -> bigdecimal
#
# Returns the value of +float+ as a BigDecimal.
# The +precision+ parameter is used to determine the number of
# significant digits for the result. When +precision+ is set to +0+,
# the number of digits to represent the float being converted is determined
# automatically.
# The default +precision+ is +0+.
#
# require 'bigdecimal'
# require 'bigdecimal/util'
#
# 0.5.to_d # => 0.5e0
# 1.234.to_d # => 0.1234e1
# 1.234.to_d(2) # => 0.12e1
#
# See also Kernel.BigDecimal.
#
def to_d(precision=0)
BigDecimal(self, precision)
end
end
class String
# call-seq:
# str.to_d -> bigdecimal
#
# Returns the result of interpreting leading characters in +str+
# as a BigDecimal.
#
# require 'bigdecimal'
# require 'bigdecimal/util'
#
# "0.5".to_d # => 0.5e0
# "123.45e1".to_d # => 0.12345e4
# "45.67 degrees".to_d # => 0.4567e2
#
# See also Kernel.BigDecimal.
#
def to_d
BigDecimal.interpret_loosely(self)
end
end
class BigDecimal < Numeric
# call-seq:
# a.to_digits -> string
#
# Converts a BigDecimal to a String of the form "nnnnnn.mmm".
# This method is deprecated; use BigDecimal#to_s("F") instead.
#
# require 'bigdecimal/util'
#
# d = BigDecimal("3.14")
# d.to_digits # => "3.14"
#
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
# call-seq:
# a.to_d -> bigdecimal
#
# Returns self.
#
# require 'bigdecimal/util'
#
# d = BigDecimal("3.14")
# d.to_d # => 0.314e1
#
def to_d
self
end
end
class Rational < Numeric
# call-seq:
# rat.to_d(precision) -> bigdecimal
#
# Returns the value as a BigDecimal.
#
# The required +precision+ parameter is used to determine the number of
# significant digits for the result.
#
# require 'bigdecimal'
# require 'bigdecimal/util'
#
# Rational(22, 7).to_d(3) # => 0.314e1
#
# See also Kernel.BigDecimal.
#
def to_d(precision)
BigDecimal(self, precision)
end
end
class Complex < Numeric
# call-seq:
# cmp.to_d -> bigdecimal
# cmp.to_d(precision) -> bigdecimal
#
# Returns the value as a BigDecimal.
#
# The +precision+ parameter is required for a rational complex number.
# This parameter is used to determine the number of significant digits
# for the result.
#
# require 'bigdecimal'
# require 'bigdecimal/util'
#
# Complex(0.1234567, 0).to_d(4) # => 0.1235e0
# Complex(Rational(22, 7), 0).to_d(3) # => 0.314e1
#
# See also Kernel.BigDecimal.
#
def to_d(*args)
BigDecimal(self) unless self.imag.zero? # to raise eerror
if args.length == 0
case self.real
when Rational
BigDecimal(self.real) # to raise error
end
end
self.real.to_d(*args)
end
end
class NilClass
# call-seq:
# nil.to_d -> bigdecimal
#
# Returns nil represented as a BigDecimal.
#
# require 'bigdecimal'
# require 'bigdecimal/util'
#
# nil.to_d # => 0.0
#
def to_d
BigDecimal(0)
end
end