1 files changed, 43 insertions, 0 deletions
diff --git a/lib/prism/debug.rb b/lib/prism/debug.rb
index c888436e4d..553205a04b 100644
--- a/lib/prism/debug.rb
+++ b/lib/prism/debug.rb
@@ -202,5 +202,48 @@ module Prism
     def self.newlines(source)
       Prism.parse(source).source.offsets
     end
+
+    # A wrapping around prism's internal encoding data structures. This is used
+    # for reflection and debugging purposes.
+    class Encoding
+      # The name of the encoding, that can be passed to Encoding.find.
+      attr_reader :name
+
+      # Initialize a new encoding with the given name and whether or not it is
+      # a multibyte encoding.
+      def initialize(name, multibyte)
+        @name = name
+        @multibyte = multibyte
+      end
+
+      # Whether or not the encoding is a multibyte encoding.
+      def multibyte?
+        @multibyte
+      end
+
+      # Returns the number of bytes of the first character in the source string,
+      # if it is valid for the encoding. Otherwise, returns 0.
+      def width(source)
+        Encoding._width(name, source)
+      end
+
+      # Returns true if the first character in the source string is a valid
+      # alphanumeric character for the encoding.
+      def alnum?(source)
+        Encoding._alnum?(name, source)
+      end
+
+      # Returns true if the first character in the source string is a valid
+      # alphabetic character for the encoding.
+      def alpha?(source)
+        Encoding._alpha?(name, source)
+      end
+
+      # Returns true if the first character in the source string is a valid
+      # uppercase character for the encoding.
+      def upper?(source)
+        Encoding._upper?(name, source)
+      end
+    end
   end
 end