EAGLESIX-2651: Expression: fix missing require

lib/pipeline/expressions/Expression.js

@@ -19,7 +19,8 @@ var Expression = module.exports = function Expression() {
 
 
 var Value = require("../Value"),
-	Document = require("../Document");
+	Document = require("../Document"),
+	Variables = require("./Variables");
 
 
 /**
@@ -84,12 +85,12 @@ var ObjectCtx = Expression.ObjectCtx = (function() {
  */
 klass.parseObject = function parseObject(obj, ctx, vps) {
 	if (!(ctx instanceof ObjectCtx)) throw new Error("ctx must be ObjectCtx");
-    /*
-      An object expression can take any of the following forms:
+	/*
+	  An object expression can take any of the following forms:
 
-      f0: {f1: ..., f2: ..., f3: ...}
-      f0: {$operator:[operand1, operand2, ...]}
-    */
+	  f0: {f1: ..., f2: ..., f3: ...}
+	  f0: {$operator:[operand1, operand2, ...]}
+	*/
 
 	var expression, // the result
 		expressionObject, // the alt result
@@ -205,7 +206,7 @@ klass.parseExpression = function parseExpression(exprElementKey, exprElementValu
 		op = Expression.expressionParserMap;
 	if (!op) throw new Error("invalid operator : " + exprElementKey + "; uassert code 15999");
 
-    // make the expression node
+	// make the expression node
 	return op(exprElementValue, vps);
 };