Coerce state names into symbols instead of strings

lib/rouge/regex_lexer.rb

@@ -183,18 +183,18 @@ def self.start(&b)
     # Define a new state for this lexer with the given name.
     # The block will be evaluated in the context of a {StateDSL}.
     def self.state(name, &b)
-      name = name.to_s
+      name = name.to_sym
       state_definitions[name] = StateDSL.new(name, &b)
     end
 
     def self.prepend(name, &b)
-      name = name.to_s
+      name = name.to_sym
       dsl = state_definitions[name] or raise "no such state #{name.inspect}"
       replace_state(name, dsl.prepended(&b))
     end
 
     def self.append(name, &b)
-      name = name.to_s
+      name = name.to_sym
       dsl = state_definitions[name] or raise "no such state #{name.inspect}"
       replace_state(name, dsl.appended(&b))
     end
@@ -204,7 +204,7 @@ def self.get_state(name)
       return name if name.is_a? State
 
       states[name.to_sym] ||= begin
-        defn = state_definitions[name.to_s] or raise "unknown state: #{name.inspect}"
+        defn = state_definitions[name.to_sym] or raise "unknown state: #{name.inspect}"
         defn.to_state(self)
       end
     end