first draft of parsing and printing along comments -- unfortunately, not yet working within objects and arrays

lib/coffee_script/grammar.y

@@ -13,6 +13,7 @@ token SWITCH CASE
 token EXTENDS SUPER
 token DELETE
 token NEWLINE
+token COMMENT
 token JS
 
 # Declare order of operations.
@@ -81,6 +82,7 @@ rule
   | While
   | For
   | Switch
+  | Comment
   ;
 
   # All tokens that can terminate an expression.
@@ -123,6 +125,11 @@ rule
     RETURN Expression                 { result = ReturnNode.new(val[1]) }
   ;
 
+  # A comment.
+  Comment:
+    COMMENT                           { result = CommentNode.new(val[0]) }
+  ;
+
   # Arithmetic and logical operators
   # For Ruby's Operator precedence, see:
   # https://www.cs.auckland.ac.nz/references/ruby/ProgrammingRuby/language.html