Refactor to a regex-based algorithm

.rubocop.yml

@@ -49,3 +49,8 @@ RSpec/MultipleExpectations:
 
 RSpec/NestedGroups:
   Enabled: false
+
+RSpec/FilePath:
+  Exclude:
+    - spec/uri/idna/validation/contexto_spec.rb
+    - spec/uri/idna/validation/contextj_spec.rb

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning].
 
 ## [Unreleased]
 
+### Changed
+
+- Internal implementation moved to regex-based algorithm to improve performance. ([@skryukov])
+
 ## [0.2.1] - 2023-11-15
 
 ### Changed

lib/uri/idna/base_processing.rb

@@ -1,27 +1,33 @@
 # frozen_string_literal: true
 
 require_relative "validation/label"
-require_relative "validation/codepoint"
 require_relative "validation/bidi"
 
 module URI
   module IDNA
     class BaseProcessing
+      class << self
+        def default_options
+          @default_options ||= options_class.new
+        end
+
+        def options_class
+          raise NotImplementedError, "Implement #options_class method"
+        end
+      end
+
       def initialize(domain_name, **options)
         @domain_name = domain_name
-        @options = options_class.new(**options)
+        @options = options.any? ? self.class.options_class.new(**options) : self.class.default_options
       end
 
       private
 
       attr_reader :domain_name, :options
 
-      def options_class
-        raise NotImplementedError, "Implement #options_class method"
-      end
-
       def punycode_decode(label)
         raise Error, "Label contains non-ASCII code point" unless label.ascii_only?
+        raise Error, "A-label must not end with a hyphen" if label[-1] == "-"
 
         code = label[ACE_PREFIX.length..]
         raise Error, "Malformed A-label, no Punycode eligible content found" if code.empty?