All apps should only match page[123], else return 404. Shows new Syro route match method `at`.

at_app.rb

App = Syro.new do
  on :token do
    at 'page1' do
      get { res.text 'page1' }
    end

    at 'page2' do
      get { res.text 'page2' }
    end

    at 'page3' do
      get { res.text 'page3' }
    end

    res.text '404'  # :token branch 404
  end

  res.text '404'  # app 404
end

call.rb

env = { # page1
  "REQUEST_METHOD" => "GET",
  "PATH_INFO"      => "/page1",
}
p App.call(env)

env = { # 404
  "REQUEST_METHOD" => "GET",
  "PATH_INFO"      => "/pageX",
}
p App.call(env)

env = { # 404
  "REQUEST_METHOD" => "GET",
  "PATH_INFO"      => "/page1/nonexistent",
}
p App.call(env)

env = { # 404
  "REQUEST_METHOD" => "GET",
  "PATH_INFO"      => "/",
}
p App.call(env)

inbox_app.rb

App = Syro.new do
  on :token do
    root do
      on inbox[:token] == 'page1' do
        get { res.text 'page1' }
      end

      on inbox[:token] == 'page2' do
        get { res.text 'page2' }
      end

      on inbox[:token] == 'page3' do
        get { res.text 'page3' }
      end

      res.text '404'  # :token branch root-only 404
    end

    res.text '404'  # :token branch 404
  end

  res.text '404'  # app 404
end

on_app.rb

App = Syro.new do
  on 'page1' do
    get { res.text 'page1' }
    res.text '404'  # page1 404
  end

  on 'page2' do
    get { res.text 'page2' }
    res.text '404'  # page2 404
  end

  on 'page3' do
    get { res.text 'page3' }
    res.text '404'  # page3 404
  end

  res.text '404'  # app 404
end

output.txt

[200, {"Content-Type"=>"text/plain", "Content-Length"=>"5"}, ["page1"]]
[404, {"Content-Type"=>"text/plain", "Content-Length"=>"3"}, ["404"]]
[404, {"Content-Type"=>"text/plain", "Content-Length"=>"3"}, ["404"]]
[404, {"Content-Type"=>"text/plain", "Content-Length"=>"3"}, ["404"]]

syro.patch

--- syro-3.0.1/lib/syro.rb      Thu Jan 25 15:24:37 2018
+++ /tmp/syro.rb        Thu Jan 25 15:24:20 2018
@@ -302,6 +302,7 @@
       end

       def capture(arg)
+        @syro_last_capture = arg
         @syro_path.capture(arg, inbox)
       end

@@ -328,6 +329,10 @@

       def root
         default { yield } if root?
+      end
+
+      def at(arg)
+        root { yield } if arg == inbox[@syro_last_capture]
       end

       def get