Contents

#
# Time math is handled slightly differently.  The difference is considered to be an exact duration if
# the subtracted value is in hours, minutes, or seconds.  It is rounded to the nearest day if the offset
# is in years, decades, or centuries.  This leads to less precise values, but ones that match the 
# calendar better.
class Time
  
  class << self
    alias unit_time_at at
  end
  
  def self.at(*args)
    if Unit === args[0]
      unit_time_at(args[0].to("s").scalar)
    else
      unit_time_at(*args)
    end
  end
  
  def to_unit(other = nil)
    other ? Unit.new(self).to(other) : Unit.new(self)
  end
  alias :unit :to_unit
  alias :u :to_unit
  alias :unit_add :+
  
  def to_datetime
    DateTime.civil(1970,1,1)+(self.to_f+self.gmt_offset)/86400
  end
  
  # ruby 1.8.6 has a reasonable implementation of this that works well, so let's use it.
  if VERSION == "1.8.4"
    def to_date
      x=(Date.civil(1970,1,1)+((self.to_f+self.gmt_offset)/86400.0)-0.5)
      Date.civil(x.year, x.month, x.day )
    end
  end
  
  def +(other)
    case other
    when Unit:
      other = other.to('d').round.to('s') if ['y', 'decade', 'century'].include? other.units  
      begin
        unit_add(other.to('s').scalar)
      rescue RangeError
        self.to_datetime + other
      end
    when DateTime: unit_add(other.to_time)
    else
      unit_add(other)
    end
  end
  
  # usage: Time.in '5 min'
  def self.in(duration)
    Time.now + duration.to_unit
  end
  
  alias :unit_sub :-
  
  def -(other)
    case other
    when Unit: 
      other = other.to('d').round.to('s') if ['y', 'decade', 'century'].include? other.units  
      begin
        unit_sub(other.to('s').scalar)
      rescue RangeError
        self.to_datetime - other
      end
      
    when DateTime: unit_sub(other.to_time)
    else
      unit_sub(other)
    end
  end
end

Version data entries

4 entries across 4 versions & 1 rubygems

Version	Path
ruby-units-1.1.5	lib/ruby_units/time.rb
ruby-units-1.1.4	lib/ruby_units/time.rb
ruby-units-1.1.2	lib/ruby_units/time.rb
ruby-units-1.1.3	lib/ruby_units/time.rb