1 files changed, 61 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/journey/scanner.rb b/actionpack/lib/action_dispatch/journey/scanner.rb
new file mode 100644
index 0000000000..19e0bc03d6
--- /dev/null
+++ b/actionpack/lib/action_dispatch/journey/scanner.rb
@@ -0,0 +1,61 @@
+require 'strscan'
+
+module ActionDispatch
+  module Journey # :nodoc:
+    class Scanner # :nodoc:
+      def initialize
+        @ss = nil
+      end
+
+      def scan_setup(str)
+        @ss = StringScanner.new(str)
+      end
+
+      def eos?
+        @ss.eos?
+      end
+
+      def pos
+        @ss.pos
+      end
+
+      def pre_match
+        @ss.pre_match
+      end
+
+      def next_token
+        return if @ss.eos?
+
+        until token = scan || @ss.eos?; end
+        token
+      end
+
+      private
+
+        def scan
+          case
+            # /
+          when text = @ss.scan(/\//)
+            [:SLASH, text]
+          when text = @ss.scan(/\*\w+/)
+            [:STAR, text]
+          when text = @ss.scan(/(?<!\\)\(/)
+            [:LPAREN, text]
+          when text = @ss.scan(/(?<!\\)\)/)
+            [:RPAREN, text]
+          when text = @ss.scan(/\|/)
+            [:OR, text]
+          when text = @ss.scan(/\./)
+            [:DOT, text]
+          when text = @ss.scan(/(?<!\\):\w+/)
+            [:SYMBOL, text]
+          when text = @ss.scan(/(?:[\w%\-~!$&'*+,;=@]|\\:|\\\(|\\\))+/)
+            [:LITERAL, text.tr('\\', '')]
+            # any char
+          when text = @ss.scan(/./)
+            [:LITERAL, text]
+          end
+        end
+    end
+  end
+end