They should be in the same layer

lib/hamlit/engine.rb

@@ -4,7 +4,6 @@ require 'hamlit/attribute_sorter'
 require 'hamlit/compiler'
 require 'hamlit/dynamic_formatter'
 require 'hamlit/filter_compiler'
-require 'hamlit/filter_formatter'
 require 'hamlit/html/pretty'
 require 'hamlit/html/ugly'
 require 'hamlit/multiline'
@@ -22,7 +21,6 @@ module Hamlit
 
     use Multiline
     use Parser
-    use FilterFormatter
     use FilterCompiler
     use Compiler
     use AttributeCompiler

lib/hamlit/filter_compiler.rb

@@ -8,13 +8,53 @@ module Hamlit
   class FilterCompiler < Hamlit::Filter
     extend Concerns::Registerable
 
+    BASE_DEPTH      = 2
+    IGNORED_FILTERS = %w[ruby].freeze
+
     register :javascript, Filters::Javascript
     register :css,        Filters::Css
     register :ruby,       Filters::Ruby
 
     def on_haml_filter(name, exp)
+      exp = format_expressions(name, exp)
+
       compiler = FilterCompiler.find(name)
       compiler.compile(exp)
     end
+
+    private
+
+    def format_expressions(name, lines)
+      return lines if IGNORED_FILTERS.include?(name)
+
+      lines = [''] if lines.empty?
+      lines = unindent_lines(lines)
+
+      [:multi, [:static, "\n"], *wrap_newlines(lines)]
+    end
+
+    def unindent_lines(lines)
+      base = lines.first.index(/[^\s]/) || 0
+      lines.map do |line|
+        change_indent(line, BASE_DEPTH - base)
+      end
+    end
+
+    def change_indent(line, diff)
+      if diff >= 0
+        ((' ' * diff) + line).gsub(/ *\Z/, '')
+      else
+        line.gsub(/^[[:blank:]]{#{-1 * diff}}/, '')
+      end
+    end
+
+    def wrap_newlines(lines)
+      ast = []
+      lines.each do |line|
+        ast << [:haml, :text, line]
+        ast << [:static, "\n"]
+      end
+      ast
+    end
   end
 end

lib/hamlit/filter_formatter.rb

@@ -1,44 +0,0 @@
-require 'hamlit/filter'
-
-module Hamlit
-  class FilterFormatter < Hamlit::Filter
-    BASE_DEPTH      = 2
-    IGNORED_FILTERS = %w[ruby].freeze
-
-    def on_haml_filter(name, lines)
-      return [:haml, :filter, name, lines] if IGNORED_FILTERS.include?(name)
-
-      lines = [''] if lines.empty?
-      lines = unindent_lines(lines)
-
-      multi = [:multi, [:static, "\n"], *wrap_newlines(lines)]
-      [:haml, :filter, name, multi]
-    end
-
-    private
-
-    def unindent_lines(lines)
-      base = lines.first.index(/[^\s]/) || 0
-      lines.map do |line|
-        change_indent(line, BASE_DEPTH - base)
-      end
-    end
-
-    def change_indent(line, diff)
-      if diff >= 0
-        ((' ' * diff) + line).gsub(/ *\Z/, '')
-      else
-        line.gsub(/^[[:blank:]]{#{-1 * diff}}/, '')
-      end
-    end
-
-    def wrap_newlines(lines)
-      ast = []
-      lines.each do |line|
-        ast << [:haml, :text, line]
-        ast << [:static, "\n"]
-      end
-      ast
-    end
-  end
-end