diff --git a/src/actions.cr b/src/actions.cr
index 5e96f7c..85b5c9c 100644
--- a/src/actions.cr
+++ b/src/actions.cr
@@ -9,12 +9,12 @@ require "./tartrazine"
 # or change the state machine.
 module Tartrazine
   enum ActionType
-    Token
-    Push
-    Pop
-    Combined
     Bygroups
+    Combined
     Include
+    Pop
+    Push
+    Token
     Using
     Usingself
   end
diff --git a/src/bytes_regex.cr b/src/bytes_regex.cr
index 701cdf8..c73f694 100644
--- a/src/bytes_regex.cr
+++ b/src/bytes_regex.cr
@@ -57,7 +57,7 @@ module BytesRegex
     end
   end
 
-  class Match
+  struct Match
     property value : Bytes
     property start : UInt64
     property size : UInt64
diff --git a/src/lexer.cr b/src/lexer.cr
index 632e274..800dfb9 100644
--- a/src/lexer.cr
+++ b/src/lexer.cr
@@ -44,7 +44,7 @@ module Tartrazine
   # For explanations on what actions and states do
   # the Pygments documentation is a good place to start.
   # https://pygments.org/docs/lexerdevelopment/
-  class Lexer
+  struct Lexer
     property config = {
       name:             "",
       aliases:          [] of String,
diff --git a/src/rules.cr b/src/rules.cr
index dc07899..597ea65 100644
--- a/src/rules.cr
+++ b/src/rules.cr
@@ -19,7 +19,7 @@ module Tartrazine
     abstract def match(text : Bytes, pos, lexer) : Tuple(Bool, Int32, Array(Token))
     abstract def initialize(node : XML::Node)
 
-    property actions : Array(Action) = [] of Action
+    @actions : Array(Action) = [] of Action
 
     def add_actions(node : XML::Node)
       node.children.each do |child|
@@ -31,14 +31,13 @@ module Tartrazine
 
   struct Rule < BaseRule
     property pattern : Regex = Regex.new ""
-    property actions : Array(Action) = [] of Action
 
     def match(text : Bytes, pos, lexer) : Tuple(Bool, Int32, Array(Token))
       match = pattern.match(text, pos)
 
       # No match
       return false, pos, [] of Token if match.size == 0
-      return true, pos + match[0].size, actions.flat_map(&.emit(match, lexer))
+      return true, pos + match[0].size, @actions.flat_map(&.emit(match, lexer))
     end
 
     def initialize(node : XML::Node)
@@ -55,11 +54,10 @@ module Tartrazine
   # This rule includes another state. If any of the rules of the
   # included state matches, this rule matches.
   struct IncludeStateRule < BaseRule
-    property state : String = ""
+    @state : String = ""
 
     def match(text, pos, lexer) : Tuple(Bool, Int32, Array(Token))
-      Log.trace { "Including state #{state} from #{lexer.state_stack.last}" }
-      lexer.states[state].rules.each do |rule|
+      lexer.states[@state].rules.each do |rule|
         matched, new_pos, new_tokens = rule.match(text, pos, lexer)
         return true, new_pos, new_tokens if matched
       end
@@ -80,7 +78,7 @@ module Tartrazine
     NO_MATCH = [] of Match
 
     def match(text, pos, lexer) : Tuple(Bool, Int32, Array(Token))
-      return true, pos, actions.flat_map(&.emit(NO_MATCH, lexer))
+      return true, pos, @actions.flat_map(&.emit(NO_MATCH, lexer))
     end
 
     def initialize(node : XML::Node)