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

lib/lessphp/Tree/Expression.php

@@ -0,0 +1,97 @@
+<?php
+
+/**
+ * Expression
+ *
+ * @package Less
+ * @subpackage tree
+ */
+class Less_Tree_Expression extends Less_Tree{
+
+	public $value = array();
+	public $parens = false;
+	public $parensInOp = false;
+	public $type = 'Expression';
+
+	public function __construct( $value, $parens = null ){
+		$this->value = $value;
+		$this->parens = $parens;
+	}
+
+	function accept( $visitor ){
+		$this->value = $visitor->visitArray( $this->value );
+	}
+
+	public function compile($env) {
+
+		$doubleParen = false;
+
+		if( $this->parens && !$this->parensInOp ){
+			Less_Environment::$parensStack++;
+		}
+
+		$returnValue = null;
+		if( $this->value ){
+
+			$count = count($this->value);
+
+			if( $count > 1 ){
+
+				$ret = array();
+				foreach($this->value as $e){
+					$ret[] = $e->compile($env);
+				}
+				$returnValue = new Less_Tree_Expression($ret);
+
+			}else{
+
+				if( ($this->value[0] instanceof Less_Tree_Expression) && $this->value[0]->parens && !$this->value[0]->parensInOp ){
+					$doubleParen = true;
+				}
+
+				$returnValue = $this->value[0]->compile($env);
+			}
+
+		} else {
+			$returnValue = $this;
+		}
+
+		if( $this->parens ){
+			if( !$this->parensInOp ){
+				Less_Environment::$parensStack--;
+
+			}elseif( !Less_Environment::isMathOn() && !$doubleParen ){
+				$returnValue = new Less_Tree_Paren($returnValue);
+
+			}
+		}
+		return $returnValue;
+	}
+
+    /**
+     * @see Less_Tree::genCSS
+     */
+	function genCSS( $output ){
+		$val_len = count($this->value);
+		for( $i = 0; $i < $val_len; $i++ ){
+			$this->value[$i]->genCSS( $output );
+			if( $i + 1 < $val_len ){
+				$output->add( ' ' );
+			}
+		}
+	}
+
+	function throwAwayComments() {
+
+		if( is_array($this->value) ){
+			$new_value = array();
+			foreach($this->value as $v){
+				if( $v instanceof Less_Tree_Comment ){
+					continue;
+				}
+				$new_value[] = $v;
+			}
+			$this->value = $new_value;
+		}
+	}
+}