Can define more than one language.

interpreter.py

@@ -132,10 +132,14 @@ class Interpreter():
         print('Message: %s' % args[0])
 
     def func_language(self, node, args):
-        self.validate_arguments(args, 1, [str])
+        if len(args) == 0:
+            raise InvalidArguments('Line %d: no arguments to function language.' % node.lineno())
+        for a in args:
+            if not isinstance(a, str):
+                raise InvalidArguments('Line %d: Argument %s is not a string.' % (node.lineno(), str(a)))
         if len(self.compilers) > 0:
             raise InvalidCode('Function language() can only be called once (line %d).' % node.lineno())
-        lang = args[0]
+        for lang in args:
             if lang.lower() == 'c':
                 comp = environment.detect_c_compiler('gcc')
                 comp.sanity_check(self.scratch_dir)