Created css2sass. Still lacking a lot of functionality, like figuring out nesting and dealing with comments and @import. The basics are there, though.

git-svn-id: svn://hamptoncatlin.com/haml/trunk@476 7063305b-7217-0410-af8c-cdc13e5119b9

bin/css2sass

@@ -0,0 +1,7 @@
+#!/usr/bin/env ruby
+
+require File.dirname(__FILE__) + '/../lib/haml'
+require 'haml/exec'
+
+opts = Haml::Exec::CSS2Sass.new(ARGV)
+opts.parse!

lib/haml/exec.rb

@@ -253,5 +253,36 @@ END
         output.write(::Haml::HTML.new(input).render)
       end
     end
+
+    # A class encapsulating executable functionality
+    # specific to the css2sass executable.
+    class CSS2Sass < Generic # :nodoc:
+      def initialize(args)
+        super
+
+        require 'sass/css'
+      end
+
+      def set_opts(opts)
+        opts.banner = <<END
+Usage: css2sass [options] (css file) (output file)
+
+Description: Transforms a CSS file into corresponding Sass code.
+
+Options:
+END
+
+        super
+      end
+
+      def process_result
+        super
+
+        input = @options[:input]
+        output = @options[:output]
+
+        output.write(::Sass::CSS.new(input).render)
+      end
+    end
   end
 end

lib/sass/css.rb

@@ -0,0 +1,91 @@
+require File.dirname(__FILE__) + '/../sass'
+require 'sass/tree/node'
+require 'strscan'
+
+module Sass
+  # :stopdoc:
+  module Tree
+    class Node
+      def to_sass
+        result = ''
+
+        children.each do |child|
+          result << "#{child.to_sass(0)}\n"
+        end
+
+        result
+      end
+    end
+
+    class RuleNode
+      def to_sass(tabs)
+        str = "#{'  ' * tabs}#{rule}\n"
+
+        children.each do |child|
+          str << "#{child.to_sass(tabs + 1)}\n"
+        end
+
+        str
+      end
+    end
+
+    class AttrNode
+      def to_sass(tabs)
+        "#{'  ' * tabs}:#{name} #{value}"
+      end
+    end
+  end
+  # :startdoc:
+
+  # This class contains the functionality used in the +css2sass+ utility,
+  # namely converting CSS documents to Sass templates.
+  class CSS
+    # :stopdoc:
+
+    # The Regexp matching a CSS rule
+    RULE_RE = /\s*([^\{]+)\s*\{/
+
+    # The Regexp matching a CSS attribute
+    ATTR_RE = /\s*[^::\{\}]+\s*:\s*[^:;\{\}]+\s*;/
+
+    # :startdoc:
+
+    # Creates a new instance of Sass::CSS that will compile the given document
+    # to a Sass string when +render+ is called.
+    def initialize(template)
+      if template.is_a? IO
+        template = template.read
+      end
+
+      @template = StringScanner.new(template)
+    end
+
+    # Processes the document and returns the result as a string
+    # containing the CSS template.
+    def render
+      build_tree.to_sass
+    end
+
+    private
+
+    def build_tree
+      root = Tree::Node.new(nil)
+
+      while @template.scan(RULE_RE)
+        rule = Tree::RuleNode.new(@template[0][0...-1].strip, nil)
+        root << rule
+
+        while @template.scan(ATTR_RE)
+          attrs = @template[0][0...-1].split(':').map {|s| s.strip}
+          rule << Tree::AttrNode.new(attrs[0], attrs[1], nil)
+        end
+
+        if @template.scan(/\s*\}/).nil?
+          raise "Invalid CSS!"
+        end
+      end
+
+      root
+    end
+  end
+end