add coffee script compiler

compress/compilers/__init__.py

+import subprocess
+
 class CompilerBase(object):
-    pass
+    def __init__(self, verbose):
+        self.verbose = verbose
+
+    def match_file(self, filename):
+        raise NotImplementedError
+
+    def compile_file(self, content):
+        raise NotImplementedError
 
 
 class CompilerError(Exception):
     pass
+
+
+class SubProcessCompiler(CompilerBase):
+    def execute_command(self, command, content):
+        pipe = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE,
+            stdin=subprocess.PIPE, stderr=subprocess.PIPE)
+        pipe.stdin.write(content)
+        pipe.stdin.close()
+
+        compressed_content = pipe.stdout.read()
+        pipe.stdout.close()
+
+        error = pipe.stderr.read()
+        pipe.stderr.close()
+
+        if pipe.wait() != 0:
+            if not error:
+                error = "Unable to apply %s filter" % self.__class__.__name__
+            raise FilterError(error)
+
+        if self.verbose:
+            print error
+
+        return compressed_content

compress/compilers/coffee/__init__.py

+from compress.conf import settings
+from compress.compilers import SubProcessCompiler
+
+
+class CoffeeScriptCompiler(SubProcessCompiler):
+    def match_file(self, filename):
+        return filename.endswith('.coffee')
+
+    def compile_file(self, content):
+        command = "%s %s" % (settings.COFFEE_SCRIPT_BINARY, settings.COFFEE_SCRIPT_ARGUMENTS)
+        if self.verbose:
+            command += '--verbose'
+        return self.execute_command(command, content)

compress/conf/settings.py

@@ -35,6 +35,9 @@ COMPRESS_CLOSURE_ARGUMENTS = getattr(settings, 'COMPRESS_CLOSURE_ARGUMENTS', '')
 COMPRESS_UGLIFYJS_BINARY = getattr(settings, 'COMPRESS_UGLIFYJS_BINARY', '/usr/local/bin/uglifyjs')
 COMPRESS_UGLIFYJS_ARGUMENTS = getattr(settings, 'COMPRESS_UGLIFYJS_ARGUMENTS', '-nc')
 
+COMPRESS_COFFEE_SCRIPT_BINARY = getattr(settings, 'COMPRESS_COFFEE_SCRIPT_BINARY', '/usr/local/bin/coffee')
+COFFEE_SCRIPT_ARGUMENTS = getattr(settings, 'COFFEE_SCRIPT_ARGUMENTS', '-sc')
+
 if COMPRESS_CSS_COMPRESSORS is None:
     COMPRESS_CSS_COMPRESSORS = []