Allow configuration of optional separator on output. (#149)

CHANGELOG.txt

@@ -1,5 +1,7 @@
 Change Log for Ruby-units
 =========================
+2016-12-28  2.1.0   * add support for ruby 2.4.0
+                    * allow configuration for optional separator on output
                     * Fix issue #105 -- change 'grad' to 'gon'
 2015-11-07  2.0.0   * remove support for ruby versions less than 2.0
                     * remove `.unit` and `.u` from String

README.md

@@ -259,13 +259,29 @@ gem 'ruby-units', require: 'ruby_units/namespaced'
 
 Note: when using the namespaced version, the Unit.new('unit string') helper will not be defined.
 
+### Configuration
+
+Configuration options can be set like:
+
+```
+RubyUnits.configure do |config|
+  config.separator = false
+end
+```
+
+Currently there is only one configuration you can set:
+
+1. separator (true/false): should a space be used to separate the scalar from the unit part during output.
+
+
 ### NOTES
 
 #### Mathn
 
 Note that the current implementation of ruby-units requires 'mathn' from the ruby standard library.
 This tends to change the behavior of integer math in ways that many people do not expect, and can be the source
 of numerous bugs and odd behaviors.  If you encounter what appears to be a bug in your code that seems to be related
+
 to the use of ruby-units, try to reproduce the bug by just including 'mathn' by itself.
 
 If you identify a bug in a gem or code that uses mathn, please file a bug report or create a pull request to fix it.

lib/ruby_units/configuration.rb

@@ -0,0 +1,41 @@
+# allow for optional configuration of RubyUnits
+#
+# Usage:
+#
+#     RubyUnits.configure do |config|
+#       config.separator = false
+#     end
+module RubyUnits
+  class << self
+    attr_writer :configuration
+  end
+
+  def self.configuration
+    @configuration ||= Configuration.new
+  end
+
+  def self.reset
+    @configuration = Configuration.new
+  end
+
+  def self.configure
+    yield configuration
+  end
+
+  # holds actual configuration values for RubyUnits
+  class Configuration
+    # used to separate the scalar from the unit when generating output.
+    # set to nil to prevent adding a space to the string representation of a unit
+    # separators other than ' ' and '' may work, but you may encounter problems
+    attr_reader :separator
+
+    def initialize
+      self.separator = true
+    end
+
+    def separator=(value)
+      raise ArgumentError, "configuration 'separator' may only be true or false" unless value.class == TrueClass || value.class == FalseClass
+      @separator = value ? ' ' : nil
+    end
+  end
+end

lib/ruby_units/namespaced.rb

@@ -3,6 +3,7 @@
 
 # require_relative this file to avoid creating an class alias from Unit to RubyUnits::Unit
 require_relative 'version'
+require_relative 'configuration'
 require_relative 'definition'
 require_relative 'cache'
 require_relative 'array'

lib/ruby_units/unit.rb

@@ -644,16 +644,17 @@ def to_base
     def to_s(target_units = nil)
       out = @output[target_units]
       return out if out
+      separator = RubyUnits.configuration.separator
       case target_units
       when :ft
         inches = convert_to('in').scalar.to_int
         out    = "#{(inches / 12).truncate}\'#{(inches % 12).round}\""
       when :lbs
         ounces = convert_to('oz').scalar.to_int
-        out    = "#{(ounces / 16).truncate} lbs, #{(ounces % 16).round} oz"
+        out    = "#{(ounces / 16).truncate}#{separator}lbs, #{(ounces % 16).round}#{separator}oz"
       when :stone
         pounds = convert_to('lbs').scalar.to_int
-        out = "#{(pounds / 14).truncate} stone, #{(pounds % 14).round} lb"
+        out = "#{(pounds / 14).truncate}#{separator}stone, #{(pounds % 14).round}#{separator}lb"
       when String
         out = case target_units.strip
               when /\A\s*\Z/ # whitespace only
@@ -663,7 +664,7 @@ def to_s(target_units = nil)
                   if $2 # unit specified, need to convert
                     convert_to($2).to_s($1)
                   else
-                    "#{$1 % @scalar} #{$2 || units}".strip
+                    "#{$1 % @scalar}#{separator}#{$2 || units}".strip
                   end
                 rescue # parse it like a strftime format string
                   (DateTime.new(0) + self).strftime(target_units)
@@ -676,9 +677,9 @@ def to_s(target_units = nil)
       else
         out = case @scalar
               when Rational, Complex
-                "#{@scalar} #{units}"
+                "#{@scalar}#{separator}#{units}"
               else
-                "#{'%g' % @scalar} #{units}"
+                "#{'%g' % @scalar}#{separator}#{units}"
               end.strip
       end
       @output[target_units] = out

spec/ruby_units/configuration_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+describe RubyUnits::Configuration do
+  context '.separator is true' do
+    it 'has a space between the scalar and the unit' do
+      expect(RubyUnits::Unit.new('1 m').to_s).to eq '1 m'
+    end
+  end
+
+  context '.separator is false' do
+    around(:each) do |example|
+      RubyUnits.configure do |config|
+        config.separator = false
+      end
+      example.run
+      RubyUnits.reset
+    end
+
+    it 'does not have a space between the scalar and the unit' do
+      expect(RubyUnits::Unit.new('1 m').to_s).to eq '1m'
+      expect(RubyUnits::Unit.new('14.5 lbs').to_s(:lbs)).to eq '14lbs, 8oz'
+      expect(RubyUnits::Unit.new('220 lbs').to_s(:stone)).to eq '15stone, 10lb'
+      expect(RubyUnits::Unit.new('14.2 ft').to_s(:ft)).to eq %(14'2")
+      expect(RubyUnits::Unit.new('1/2 cup').to_s).to eq '1/2cu'
+      expect(RubyUnits::Unit.new('123.55 lbs').to_s('%0.2f')).to eq '123.55lbs'
+    end
+  end
+end