Add parent selector to user variable

lib/less/parser.js

@@ -1001,10 +1001,29 @@ less.Parser = function Parser(env) {
             selector: function () {
                 var sel, e, elements = [], c, match;
 
-                if ($('(')) {
+                if (peek(/^&?\(/)) {
+                    // variable selectors:
+                    // allow & before a selector to allow variable selectors
+                    // to be at the same level, e.g.
+                    // .a {
+                    //   &(~".b") {
+                    //
+                    // Ideally this would be part of the element function.. this would allow
+                    //  (@a).b(@c)
+                    // however this syntax conflicts with the supported syntax
+                    //   :nth-child(@a)
+                    // vs
+                    //   .a:hover(@a)
+                
+                    e = $('&');
+                    $('(');
+                    if (e) {
+                        elements.push(new(tree.Element)('', e, i));
+                    }
                     sel = $(this.entity);
                     expect(')');
-                    return new(tree.Selector)([new(tree.Element)('', sel, i)]);
+                    elements.push(new(tree.Element)('', sel, i));
+                    return new(tree.Selector)(elements);
                 }
 
                 while (e = $(this.element)) {

test/css/selectors.css

@@ -113,3 +113,12 @@ p a span {
 .other::bnord {
   color: #ff0000;
 }
+.a .b {
+  color: red;
+}
+.a.c {
+  color: black;
+}
+.a :nth-child(3) {
+  color: purple;
+}

test/less/selectors.less

@@ -107,3 +107,16 @@ a {
   ::bnord {color: red }
   &::bnord {color: red }
 }
+
+.a {
+  (~".b") {
+    color: red;
+  }
+  &(~".c") {
+    color: black;
+  }
+  @d: 3;
+  :nth-child(@d) {
+    color: purple;
+  }
+}