Removed a duplicate declaration, fixes #5

Author: Aniket Panse

lib/SymbolTree.js

@@ -480,36 +480,36 @@ class SymbolTree {
                         return -1;
                 }
 
-                let index = childNode.getCachedIndex(parentNode);
+                let currentIndex = childNode.getCachedIndex(parentNode);
 
-                if (index >= 0) {
-                        return index;
+                if (currentIndex >= 0) {
+                        return currentIndex;
                 }
 
-                index = 0;
+                currentIndex = 0;
                 let object = parentNode.firstChild;
 
                 if (parentNode.childIndexCachedUpTo) {
                         const cachedUpToNode = this._node(parentNode.childIndexCachedUpTo);
                         object = cachedUpToNode.nextSibling;
-                        index = cachedUpToNode.getCachedIndex(parentNode) + 1;
+                        currentIndex = cachedUpToNode.getCachedIndex(parentNode) + 1;
                 }
 
                 while (object) {
                         const node = this._node(object);
-                        node.setCachedIndex(parentNode, index);
+                        node.setCachedIndex(parentNode, currentIndex);
 
                         if (object === child) {
                                 break;
                         }
 
-                        ++index;
+                        ++currentIndex;
                         object = node.nextSibling;
                 }
 
                 parentNode.childIndexCachedUpTo = child;
 
-                return index;
+                return currentIndex;
         }
 
         /**