diff --git a/src/ol/expression/lexer.js b/src/ol/expression/lexer.js
index e4a2138515..5ced440e0a 100644
--- a/src/ol/expression/lexer.js
+++ b/src/ol/expression/lexer.js
@@ -134,7 +134,7 @@ ol.expression.Lexer = function(source) {
 
 
 /**
- * Scan the next token and throw if it doesn't match.
+ * Scan the next token and throw if it isn't a punctuator that matches input.
  * @param {string} value Token value.
  */
 ol.expression.Lexer.prototype.expect = function(value) {
@@ -426,6 +426,20 @@ ol.expression.Lexer.prototype.next = function() {
 };
 
 
+/**
+ * Peek at the next token, but don't advance the index.
+ *
+ * @return {ol.expression.Token} The upcoming token.
+ */
+ol.expression.Lexer.prototype.peek = function() {
+  var currentIndex = this.index_;
+  var token = this.next();
+  this.nextIndex_ = this.index_;
+  this.index_ = currentIndex;
+  return token;
+};
+
+
 /**
  * Scan hex literal as numeric token.
  *
@@ -792,6 +806,14 @@ ol.expression.Lexer.prototype.scanStringLiteral_ = function(quote) {
 };
 
 
+/**
+ * After peeking, skip may be called to advance the cursor without re-scanning.
+ */
+ol.expression.Lexer.prototype.skip = function() {
+  this.index_ = this.nextIndex_;
+};
+
+
 /**
  * Skip all whitespace.
  * @return {number} The character code of the first non-whitespace character.
@@ -809,25 +831,3 @@ ol.expression.Lexer.prototype.skipWhitespace_ = function() {
   }
   return code;
 };
-
-
-/**
- * Peek at the next token, but don't advance the index.
- *
- * @return {ol.expression.Token} The upcoming token.
- */
-ol.expression.Lexer.prototype.peek = function() {
-  var currentIndex = this.index_;
-  var token = this.next();
-  this.nextIndex_ = this.index_;
-  this.index_ = currentIndex;
-  return token;
-};
-
-
-/**
- * After peeking, skip may be called to advance the cursor without re-scanning.
- */
-ol.expression.Lexer.prototype.skip = function() {
-  this.index_ = this.nextIndex_;
-};