add single-line comments

Author: tj

examples/example.css

@@ -8,7 +8,11 @@ body
   background: black
   color: white
 
+// just an example comment
+
 button
+  // moar comments
+  // hurrrrrrrr
   border-radius: 5px
   padding: 5px 10px
   box-shadow:
@@ -17,9 +21,10 @@ button
     inset 0 0 3px blue
 
 @media print
+  // some stuff
   body
     padding: 0
 
   button
     border-radius: 0
-    width: 100%
+    width: 100%

lib/lexer.js

@@ -44,6 +44,7 @@ module.exports = function(str) {
   function next() {
     return stashed()
       || blank()
+      || comment()
       || indentation()
       || prop()
       || rule();
@@ -68,6 +69,18 @@ module.exports = function(str) {
     return next();
   }
 
+  /**
+   * Comment.
+   */
+  
+  function comment() {
+    var m = str.match(/^\/\/([^\n]*)/);
+    if (!m) return;
+    str = str.slice(m[0].length);
+    return next();
+  }
+
+
   /**
    *   INDENT
    * | OUTDENT