MDL-44357 theme: Allow core to compile LESS in PHP

lib/lessphp/Tree/Assignment.php

@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * Assignment
+ *
+ * @package Less
+ * @subpackage tree
+ */
+class Less_Tree_Assignment extends Less_Tree{
+
+	public $key;
+	public $value;
+	public $type = 'Assignment';
+
+	function __construct($key, $val) {
+		$this->key = $key;
+		$this->value = $val;
+	}
+
+	function accept( $visitor ){
+		$this->value = $visitor->visitObj( $this->value );
+	}
+
+	public function compile($env) {
+		return new Less_Tree_Assignment( $this->key, $this->value->compile($env));
+	}
+
+    /**
+     * @see Less_Tree::genCSS
+     */
+	public function genCSS( $output ){
+		$output->add( $this->key . '=' );
+		$this->value->genCSS( $output );
+	}
+
+	public function toCss(){
+		return $this->key . '=' . $this->value->toCSS();
+	}
+}