complete redesign: use nodejs on server instead of php - documentation to be updated

nodejs/node_modules/stylus/lib/functions/selector-exists.js

@@ -0,0 +1,23 @@
+var utils = require('../utils');
+
+/**
+ * Returns true if the given selector exists.
+ *
+ * @param {String} sel
+ * @return {Boolean}
+ * @api public
+ */
+
+module.exports = function selectorExists(sel) {
+  utils.assertString(sel, 'selector');
+
+  if (!this.__selectorsMap__) {
+    var Normalizer = require('../visitor/normalizer')
+      , visitor = new Normalizer(this.root.clone());
+    visitor.visit(visitor.root);
+
+    this.__selectorsMap__ = visitor.map;
+  }
+
+  return sel.string in this.__selectorsMap__;
+};