From e99f6654e118ef7f460c18346f1f7caf984f0dcc Mon Sep 17 00:00:00 2001
From: Nathan Weizenbaum <nex342@gmail.com>
Date: Thu, 16 Oct 2008 16:23:45 -0700
Subject: [PATCH] Add a SassScript repl.

---
 lib/haml/exec.rb | 11 +++++++++++
 lib/sass/repl.rb | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 lib/sass/repl.rb

diff --git a/lib/haml/exec.rb b/lib/haml/exec.rb
index 32ab8a69..f849d741 100644
--- a/lib/haml/exec.rb
+++ b/lib/haml/exec.rb
@@ -185,9 +185,20 @@ END
                 'Line Comments. Emit comments in the generated CSS indicating the corresponding sass line.') do
           @options[:for_engine][:line_comments] = true
         end
+        opts.on('-i', '--interactive',
+                'Run an interactive SassScript shell.') do
+          @options[:interactive] = true
+        end
       end
 
       def process_result
+        if @options[:interactive]
+          require 'sass'
+          require 'sass/repl'
+          ::Sass::Repl.run
+          return
+        end
+
         super
         input = @options[:input]
         output = @options[:output]
diff --git a/lib/sass/repl.rb b/lib/sass/repl.rb
new file mode 100644
index 00000000..798f5cf8
--- /dev/null
+++ b/lib/sass/repl.rb
@@ -0,0 +1,42 @@
+require 'readline'
+
+module Sass
+  module Repl
+    class << self
+      def run
+        environment = Environment.new
+        environment.set_var('important', Script::String.new('!important'))
+        loop do
+          unless text = Readline.readline('>> ')
+            puts
+            return
+          end
+
+          Readline::HISTORY << text
+          parse_input(environment, text)
+        end
+      end
+
+      private
+
+      def parse_input(environment, text)
+        case text
+        when Script::MATCH
+          name = $1
+          guarded = $2 == '||='
+          val = Script::Parser.parse($3)
+
+          unless guarded && environment.var(name)
+            environment.set_var(name, val.perform(environment))
+          end
+
+          p environment.var(name)
+        else
+          p Script::Parser.parse(text).perform(environment)
+        end
+      rescue Sass::SyntaxError => e
+        puts "SyntaxError: #{e.message}"
+      end
+    end
+  end
+end