[Sass] Add basic support for a #to_scss function.

lib/sass/tree/node.rb

@@ -193,6 +193,15 @@ module Sass
         raise NotImplementedError.new("All static-node subclasses of Sass::Tree::Node must override #to_sass.")
       end
 
+      # Converts a node to SCSS code that will generate it.
+      #
+      # @param tabs [Fixnum] The amount of tabulation to use for the SCSS code
+      # @param opts [{Symbol => Object}] An options hash (see {Sass::CSS#initialize})
+      # @return [String] The Sass code corresponding to the node
+      def to_scss(tabs = 0, opts = {})
+        raise NotImplementedError.new("All static-node subclasses of Sass::Tree::Node must override #to_scss.")
+      end
+
       protected
 
       # Computes the CSS corresponding to this particular Sass node.
@@ -319,11 +328,16 @@ module Sass
       # @param opts [{Symbol => Object}] An options hash (see {Sass::CSS#initialize})
       # @return [String] The Sass code corresponding to the children
       def children_to_sass(tabs, opts)
-        str = ""
-        children.each do |child|
-          str << "#{child.to_sass(tabs + 1, opts)}"
-        end
-        str
+        children.map {|c| c.to_sass(tabs + 1, opts)}.join
+      end
+
+      # Converts the children of this node to an SCSS string.
+      #
+      # @param tabs [Fixnum] The amount of tabulation to use for the SCSS code
+      # @param opts [{Symbol => Object}] An options hash (see {Sass::CSS#initialize})
+      # @return [String] The SCSS code corresponding to the children
+      def children_to_scss(tabs, opts)
+        children.map {|c| c.to_scss(tabs + 1, opts)}.join
       end
     end
   end

lib/sass/tree/prop_node.rb

@@ -103,6 +103,26 @@ module Sass::Tree
         children_to_sass(tabs, opts)
     end
 
+    # @see Node#to_scss
+    def to_scss(tabs, opts = {})
+      name = self.name.map {|n| n.is_a?(String) ? n : "\#{#{n.to_sass}}"}.join
+
+      if self.value.size == 1 && self.value.first.is_a?(Sass::Script::Node)
+        mid = '='
+        value = self.value.first.to_sass
+      else
+        mid = ':'
+        value = self.value.map do |n|
+          next n if n.is_a?(String)
+          "\#{#{n.to_sass}}"
+        end.join
+      end
+
+      value.gsub!(/\n[ \t]*/, "\n#{'  ' * (tabs + 1)}")
+      "#{'  ' * tabs}#{name}#{mid} #{value};\n" +
+        children_to_scss(tabs, opts)
+    end
+
     protected
 
     # Computes the CSS for the property.

lib/sass/tree/root_node.rb

@@ -52,6 +52,14 @@ module Sass
         children.map {|child| child.to_sass(0, opts) + "\n"}.join.rstrip + "\n"
       end
 
+      # Converts a node to SCSS code that will generate it.
+      #
+      # @param opts [{Symbol => Object}] An options hash (see {Sass::CSS#initialize})
+      # @return [String] The SCSS code corresponding to the node
+      def to_scss(opts = {})
+        children.map {|child| child.to_scss(0, opts) + "\n\n"}.join.rstrip + "\n"
+      end
+
       protected
 
       # Destructively converts this static Sass node into a static CSS node,

lib/sass/tree/rule_node.rb

@@ -119,6 +119,12 @@ module Sass::Tree
       "#{name.gsub(/^/, '  ' * tabs)}\n" + children_to_sass(tabs, opts)
     end
 
+    def to_scss(tabs, opts = {})
+      name = rule.map {|r| r.is_a?(String) ? r : "\#{#{r.to_sass}}"}.
+        join.gsub(/^[ \t]*/, '  ' * tabs)
+      "#{name} {\n#{children_to_scss(tabs, opts).rstrip} }\n"
+    end
+
     protected
 
     # Computes the CSS for the rule.