1  require 'yaml'
   2 
   3  module ActiveSupport #:nodoc:
   4    module CoreExtensions #:nodoc:
   5      module BigDecimal #:nodoc:
   6        module Conversions
   7          DEFAULT_STRING_FORMAT = 'F'.freeze
   8          YAML_TAG = 'tag:yaml.org,2002:float'.freeze
   9          YAML_MAPPING = { 'Infinity' => '.Inf', '-Infinity' => '-.Inf', 'NaN' => '.NaN' }
  10 
  11          def self.included(base) #:nodoc:
  12            base.class_eval do
  13              alias_method :_original_to_s, :to_s
  14              alias_method :to_s, :to_formatted_s
  15 
  16              yaml_as YAML_TAG
  17            end
  18          end
  19 
  20          def to_formatted_s(format = DEFAULT_STRING_FORMAT)
  21            _original_to_s(format)
  22          end
  23 
  24          # This emits the number without any scientific notation.
  25          # This is better than self.to_f.to_s since it doesn't lose precision.
  26          #
  27          # Note that reconstituting YAML floats to native floats may lose precision.
  28          def to_yaml(opts = {})
  29            YAML.quick_emit(nil, opts) do |out|
  30              string = to_s
  31              out.scalar(YAML_TAG, YAML_MAPPING[string] || string, :plain)
  32            end
  33          end
  34        end
  35      end
  36    end
  37  end