Method: RubyUnits::Unit#to_s

Defined in:
lib/ruby_units/unit.rb

#to_s(target_units = nil) ⇒ String

Generate human readable output. If the name of a unit is passed, the unit will first be converted to the target unit before output. some named conversions are available

You can also pass a standard format string (i.e., ‘%0.2f’) or a strftime format string.

output is cached so subsequent calls for the same format will be fast

Examples:

unit.to_s(:ft) - outputs in feet and inches (e.g., 6'4")
unit.to_s(:lbs) - outputs in pounds and ounces (e.g, 8 lbs, 8 oz)

Parameters:

  • target_units (Symbol) (defaults to: nil)

Returns:



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# File 'lib/ruby_units/unit.rb', line 519

def to_s(target_units=nil)
  out = @output[target_units]
  if out
    return out
  else
    case target_units
      when :ft
        inches = self.convert_to("in").scalar.to_int
        out    = "#{(inches / 12).truncate}\'#{(inches % 12).round}\""
      when :lbs
        ounces = self.convert_to("oz").scalar.to_int
        out    = "#{(ounces / 16).truncate} lbs, #{(ounces % 16).round} oz"
      when String
        out = case target_units
                when /(%[\-+\.\w#]+)\s*(.+)*/ #format string like '%0.2f in'
                  begin
                    if $2 #unit specified, need to convert
                      self.convert_to($2).to_s($1)
                    else
                      "#{$1 % @scalar} #{$2 || self.units}".strip
                    end
                  rescue # parse it like a strftime format string
                    (DateTime.new(0) + self).strftime(target_units)
                  end
                when /(\S+)/ #unit only 'mm' or '1/mm'
                  self.convert_to($1).to_s
                else
                  raise "unhandled case"
              end
      else
        out = case @scalar
                when Rational
                  "#{@scalar} #{self.units}"
                else
                  "#{'%g' % @scalar} #{self.units}"
              end.strip
    end
    @output[target_units] = out
    return out
  end
end