Allow tab indentation

Fixes #9.

lib/hamlit/concerns/indentable.rb

@@ -72,6 +72,17 @@ module Hamlit
 
         "#{length} #{label}#{'s' if length > 1}"
       end
+
+      # Replace hard tabs into 2 spaces
+      def replace_hard_tabs(template)
+        lines = []
+        template.each_line do |line|
+          lines << line.gsub(/^\t+/) do |match|
+            ' ' * (match.length * 2)
+          end
+        end
+        lines.join
+      end
     end
   end
 end

lib/hamlit/parser.rb

@@ -40,6 +40,7 @@ module Hamlit
     # Reset the parser state.
     def reset(template)
       validate_indentation!(template)
+      template = replace_hard_tabs(template)
       template = preprocess_multilines(template)
 
       reset_lines(template.split("\n"))

spec/hamlit/engine/indent_spec.rb

@@ -0,0 +1,14 @@
+describe Hamlit::Engine do
+  describe 'tab indent' do
+    it 'accepts tab indentation' do
+      assert_render(<<-HAML, <<-HTML)
+        %p
+        \t%a
+      HAML
+        <p>
+        <a></a>
+        </p>
+      HTML
+    end
+  end
+end