diff --git a/.gitignore b/.gitignore
index 18cfc0a..37e93ab 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,5 @@
 mkmf.log
 tags
 /coverage/
+
+/spec/examples.txt
diff --git a/.rspec b/.rspec
index 83e16f8..4115227 100644
--- a/.rspec
+++ b/.rspec
@@ -1,2 +1,2 @@
 --color
---require spec_helper
+--require gem_helper
diff --git a/lib/regexp-examples/chargroup_parser.rb b/lib/regexp-examples/chargroup_parser.rb
index 37c6c30..1bdbf1d 100644
--- a/lib/regexp-examples/chargroup_parser.rb
+++ b/lib/regexp-examples/chargroup_parser.rb
@@ -1,4 +1,6 @@
 require_relative 'parser_helpers/charset_negation_helper'
+require_relative 'parser_helpers/parse_group_helper'
+require_relative 'parser_helpers/parse_after_backslash_group_helper'
 
 module RegexpExamples
   # A "sub-parser", for char groups in a regular expression
@@ -13,6 +15,8 @@ module RegexpExamples
   # [[^:alpha:]&&[\n]a-c] - all of the above!!!! (should match "\n")
   class ChargroupParser
     include CharsetNegationHelper
+    include ParseGroupHelper
+    include ParseAfterBackslashGroupHelper
 
     attr_reader :regexp_string, :current_position
     alias length current_position
@@ -37,7 +41,6 @@ def parse
           parse_after_ampersand
         else
           @charset.concat parse_checking_backlash
-          @current_position += 1
         end
       end
 
@@ -79,15 +82,23 @@ def parse_checking_backlash
         @current_position += 1
         parse_after_backslash
       else
-        [next_char]
+        r = [next_char]
+        @current_position += 1
+        r
       end
     end
 
     def parse_after_backslash
       if next_char == 'b'
+        @current_position += 1
         ["\b"]
+      elsif rest_of_string =~ /\Au(\h{4}|\{\h{1,4}\})/
+        @current_position += 1
+        parse_backslash_unicode_sequence(Regexp.last_match(1)).result.map(&:to_s)
       else
-        CharSets::BackslashCharMap.fetch(next_char, [next_char])
+        char = CharSets::BackslashCharMap.fetch(next_char, [next_char])
+        @current_position += 1
+        char
       end
     end
 
@@ -117,13 +128,18 @@ def parse_sub_group_intersect
     end
 
     def parse_after_hyphen
-      if regexp_string[@current_position + 1] == ']' # e.g. /[abc-]/ -- not a range!
+      r = if regexp_string[@current_position + 1] == ']' # e.g. /[abc-]/ -- not a range!
+        @current_position += 1
         @charset << '-'
+      elsif rest_of_string =~ /\A-\\u(\h{4}|\{\h{1,4}\})/
+        @current_position += 3
+        char = parse_backslash_unicode_sequence(Regexp.last_match(1)).result.first.to_s
+        @charset.concat((@charset.last..char).to_a)
       else
         @current_position += 1
         @charset.concat((@charset.last..parse_checking_backlash.first).to_a)
       end
-      @current_position += 1
+      r
     end
 
     def rest_of_string
diff --git a/regexp-examples.gemspec b/regexp-examples.gemspec
index 019b7d5..a74d3b3 100644
--- a/regexp-examples.gemspec
+++ b/regexp-examples.gemspec
@@ -13,10 +13,10 @@ Gem::Specification.new do |s|
   s.executables      = s.files.grep(/^bin\//) { |f| File.basename(f) }
   s.test_files       = s.files.grep(/^(test|spec|features)\//)
   s.require_paths    = ['lib']
-  s.homepage         =
-    'http://rubygems.org/gems/regexp-examples'
-  s.add_development_dependency 'bundler'
+  s.homepage         = 'http://rubygems.org/gems/regexp-examples'
+  s.add_development_dependency 'bundler', '> 1.7'
   s.add_development_dependency 'rake', '~> 12.0'
+  s.add_development_dependency 'pry', '~> 0.12.0'
   s.license          = 'MIT'
   s.required_ruby_version = '>= 2.4.0'
 end
diff --git a/spec/gem_helper.rb b/spec/gem_helper.rb
new file mode 100644
index 0000000..651249f
--- /dev/null
+++ b/spec/gem_helper.rb
@@ -0,0 +1,19 @@
+require 'spec_helper'
+
+require 'coveralls'
+Coveralls.wear!
+
+require './lib/regexp-examples.rb'
+require 'helpers'
+require 'pry'
+
+# Several of these tests (intentionally) use "weird" regex patterns,
+# that spam annoying warnings when running.
+# E.g. warning: invalid back reference: /\k/
+# and  warning: character class has ']' without escape: /[]]/
+# This config disables those warnings.
+$VERBOSE = nil
+
+RSpec.configure do |config|
+  config.include Helpers
+end
diff --git a/spec/regexp-examples_spec.rb b/spec/regexp-examples_spec.rb
index c5a429a..3c49b5c 100644
--- a/spec/regexp-examples_spec.rb
+++ b/spec/regexp-examples_spec.rb
@@ -72,6 +72,7 @@ def self.examples_are_empty(*regexps)
         /[abc]/,
         /[a-c]/,
         /[abc-e]/,
+        /[\u4e00-\u9fa5]/,
         /[^a-zA-Z]/,
         /[\w]/,
         /[]]/,
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 1c10d08..efdd8ec 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,28 +1,30 @@
-require 'coveralls'
-Coveralls.wear!
-
-require './lib/regexp-examples.rb'
-require 'helpers'
-require 'pry'
-
-# Several of these tests (intentionally) use "weird" regex patterns,
-# that spam annoying warnings when running.
-# E.g. warning: invalid back reference: /\k/
-# and  warning: character class has ']' without escape: /[]]/
-# This config disables those warnings.
-$VERBOSE = nil
-
+# This file was generated by the `rspec --init` command. Conventionally, all
+# specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.
+# The generated `.rspec` file contains `--require spec_helper` which will cause
+# this file to always be loaded, without a need to explicitly require it in any
+# files.
+#
+# Given that it is always loaded, you are encouraged to keep this file as
+# light-weight as possible. Requiring heavyweight dependencies from this file
+# will add to the boot time of your test suite on EVERY test run, even for an
+# individual file that may not need all of that loaded. Instead, consider making
+# a separate helper file that requires the additional dependencies and performs
+# the additional setup, and require it from the spec files that actually need
+# it.
+#
+# See http://rubydoc.info/gems/rspec-core/RSpec/Core/Configuration
 RSpec.configure do |config|
-  config.include Helpers
-
+  # rspec-expectations config goes here. You can use an alternate
+  # assertion/expectation library such as wrong or the stdlib/minitest
+  # assertions if you prefer.
   config.expect_with :rspec do |expectations|
     # This option will default to `true` in RSpec 4. It makes the `description`
     # and `failure_message` of custom matchers include text for helper methods
     # defined using `chain`, e.g.:
-    # be_bigger_than(2).and_smaller_than(4).description
-    #   # => "be bigger than 2 and smaller than 4"
+    #     be_bigger_than(2).and_smaller_than(4).description
+    #     # => "be bigger than 2 and smaller than 4"
     # ...rather than:
-    #   # => "be bigger than 2"
+    #     # => "be bigger than 2"
     expectations.include_chain_clauses_in_custom_matcher_descriptions = true
   end
 
@@ -35,10 +37,60 @@
     mocks.verify_partial_doubles = true
   end
 
+  # This option will default to `:apply_to_host_groups` in RSpec 4 (and will
+  # have no way to turn it off -- the option exists only for backwards
+  # compatibility in RSpec 3). It causes shared context metadata to be
+  # inherited by the metadata hash of host groups and examples, rather than
+  # triggering implicit auto-inclusion in groups with matching metadata.
+  config.shared_context_metadata_behavior = :apply_to_host_groups
+
+  # This allows you to limit a spec run to individual examples or groups
+  # you care about by tagging them with `:focus` metadata. When nothing
+  # is tagged with `:focus`, all examples get run. RSpec also provides
+  # aliases for `it`, `describe`, and `context` that include `:focus`
+  # metadata: `fit`, `fdescribe` and `fcontext`, respectively.
+  config.filter_run_when_matching :focus
+
+  # Allows RSpec to persist some state between runs in order to support
+  # the `--only-failures` and `--next-failure` CLI options. We recommend
+  # you configure your source control system to ignore this file.
+  config.example_status_persistence_file_path = "spec/examples.txt"
+
+  # Limits the available syntax to the non-monkey patched syntax that is
+  # recommended. For more details, see:
+  #   - http://rspec.info/blog/2012/06/rspecs-new-expectation-syntax/
+  #   - http://www.teaisaweso.me/blog/2013/05/27/rspecs-new-message-expectation-syntax/
+  #   - http://rspec.info/blog/2014/05/notable-changes-in-rspec-3/#zero-monkey-patching-mode
   config.disable_monkey_patching!
 
+  # This setting enables warnings. It's recommended, but in some cases may
+  # be too noisy due to issues in dependencies.
+  config.warnings = true
+
+  # Many RSpec users commonly either run the entire suite or an individual
+  # file, and it's useful to allow more verbose output when running an
+  # individual spec file.
+  if config.files_to_run.one?
+    # Use the documentation formatter for detailed output,
+    # unless a formatter has already been configured
+    # (e.g. via a command-line flag).
+    config.default_formatter = "doc"
+  end
+
   # Print the 10 slowest examples and example groups at the
   # end of the spec run, to help surface which specs are running
   # particularly slow.
-  # config.profile_examples = 10
+  config.profile_examples = 10
+
+  # Run specs in random order to surface order dependencies. If you find an
+  # order dependency and want to debug it, you can fix the order by providing
+  # the seed, which is printed after each run.
+  #     --seed 1234
+  config.order = :random
+
+  # Seed global randomization in this process using the `--seed` CLI option.
+  # Setting this allows you to use `--seed` to deterministically reproduce
+  # test failures related to randomization by passing the same `--seed` value
+  # as the one that triggered the failure.
+  Kernel.srand config.seed
 end