diff --git a/runtime/JavaScript/src/antlr4/tree/Trees.js b/runtime/JavaScript/src/antlr4/tree/Trees.js
index 63678d6a4..64ae02230 100644
--- a/runtime/JavaScript/src/antlr4/tree/Trees.js
+++ b/runtime/JavaScript/src/antlr4/tree/Trees.js
@@ -11,132 +11,129 @@ const {RuleContext} = require('./../RuleContext');
 const {ATN: {INVALID_ALT_NUMBER}} = require('./../atn/ATN');
 
 /** A set of utility routines useful for all kinds of ANTLR trees. */
-function Trees() {
+const Trees = {
+    /**
+     * Print out a whole tree in LISP form. {@link //getNodeText} is used on the
+     *  node payloads to get the text for the nodes.  Detect
+     *  parse trees and extract data appropriately.
+     */
+    toStringTree: function(tree, ruleNames, recog) {
+        ruleNames = ruleNames || null;
+        recog = recog || null;
+        if(recog!==null) {
+            ruleNames = recog.ruleNames;
+        }
+        let s = Trees.getNodeText(tree, ruleNames);
+        s = Utils.escapeWhitespace(s, false);
+        const c = tree.getChildCount();
+        if(c===0) {
+            return s;
+        }
+        let res = "(" + s + ' ';
+        if(c>0) {
+            s = Trees.toStringTree(tree.getChild(0), ruleNames);
+            res = res.concat(s);
+        }
+        for(let i=1;i<c;i++) {
+            s = Trees.toStringTree(tree.getChild(i), ruleNames);
+            res = res.concat(' ' + s);
+        }
+        res = res.concat(")");
+        return res;
+    },
+
+    getNodeText: function(t, ruleNames, recog) {
+        ruleNames = ruleNames || null;
+        recog = recog || null;
+        if(recog!==null) {
+            ruleNames = recog.ruleNames;
+        }
+        if(ruleNames!==null) {
+            if (t instanceof RuleContext) {
+                const altNumber = t.getAltNumber();
+                if ( altNumber!=INVALID_ALT_NUMBER ) {
+                    return ruleNames[t.ruleIndex]+":"+altNumber;
+                }
+                return ruleNames[t.ruleIndex];
+            } else if ( t instanceof ErrorNode) {
+                return t.toString();
+            } else if(t instanceof TerminalNode) {
+                if(t.symbol!==null) {
+                    return t.symbol.text;
+                }
+            }
+        }
+        // no recog for rule names
+        const payload = t.getPayload();
+        if (payload instanceof Token ) {
+            return payload.text;
+        }
+        return t.getPayload().toString();
+    },
+
+    /**
+     * Return ordered list of all children of this node
+     */
+    getChildren: function(t) {
+        const list = [];
+        for(let i=0;i<t.getChildCount();i++) {
+            list.push(t.getChild(i));
+        }
+        return list;
+    },
+
+    /**
+     * Return a list of all ancestors of this node.  The first node of
+     * list is the root and the last is the parent of this node.
+     */
+    getAncestors: function(t) {
+        let ancestors = [];
+        t = t.getParent();
+        while(t!==null) {
+            ancestors = [t].concat(ancestors);
+            t = t.getParent();
+        }
+        return ancestors;
+    },
+
+    findAllTokenNodes: function(t, ttype) {
+        return Trees.findAllNodes(t, ttype, true);
+    },
+
+    findAllRuleNodes: function(t, ruleIndex) {
+        return Trees.findAllNodes(t, ruleIndex, false);
+    },
+
+    findAllNodes: function(t, index, findTokens) {
+        const nodes = [];
+        Trees._findAllNodes(t, index, findTokens, nodes);
+        return nodes;
+    },
+
+    _findAllNodes: function(t, index, findTokens, nodes) {
+        // check this node (the root) first
+        if(findTokens && (t instanceof TerminalNode)) {
+            if(t.symbol.type===index) {
+                nodes.push(t);
+            }
+        } else if(!findTokens && (t instanceof ParserRuleContext)) {
+            if(t.ruleIndex===index) {
+                nodes.push(t);
+            }
+        }
+        // check children
+        for(let i=0;i<t.getChildCount();i++) {
+            Trees._findAllNodes(t.getChild(i), index, findTokens, nodes);
+        }
+    },
+
+    descendants: function(t) {
+        let nodes = [t];
+        for(let i=0;i<t.getChildCount();i++) {
+            nodes = nodes.concat(Trees.descendants(t.getChild(i)));
+        }
+        return nodes;
+    }
 }
 
-/**
- * Print out a whole tree in LISP form. {@link //getNodeText} is used on the
- *  node payloads to get the text for the nodes.  Detect
- *  parse trees and extract data appropriately.
- */
-Trees.toStringTree = function(tree, ruleNames, recog) {
-	ruleNames = ruleNames || null;
-	recog = recog || null;
-    if(recog!==null) {
-       ruleNames = recog.ruleNames;
-    }
-    let s = Trees.getNodeText(tree, ruleNames);
-    s = Utils.escapeWhitespace(s, false);
-    const c = tree.getChildCount();
-    if(c===0) {
-        return s;
-    }
-    let res = "(" + s + ' ';
-    if(c>0) {
-        s = Trees.toStringTree(tree.getChild(0), ruleNames);
-        res = res.concat(s);
-    }
-    for(let i=1;i<c;i++) {
-        s = Trees.toStringTree(tree.getChild(i), ruleNames);
-        res = res.concat(' ' + s);
-    }
-    res = res.concat(")");
-    return res;
-};
-
-Trees.getNodeText = function(t, ruleNames, recog) {
-	ruleNames = ruleNames || null;
-	recog = recog || null;
-    if(recog!==null) {
-        ruleNames = recog.ruleNames;
-    }
-    if(ruleNames!==null) {
-       if (t instanceof RuleContext) {
-           const altNumber = t.getAltNumber();
-           if ( altNumber!=INVALID_ALT_NUMBER ) {
-               return ruleNames[t.ruleIndex]+":"+altNumber;
-           }
-           return ruleNames[t.ruleIndex];
-       } else if ( t instanceof ErrorNode) {
-           return t.toString();
-       } else if(t instanceof TerminalNode) {
-           if(t.symbol!==null) {
-               return t.symbol.text;
-           }
-       }
-    }
-    // no recog for rule names
-    const payload = t.getPayload();
-    if (payload instanceof Token ) {
-       return payload.text;
-    }
-    return t.getPayload().toString();
-};
-
-
-/**
- * Return ordered list of all children of this node
- */
-Trees.getChildren = function(t) {
-	const list = [];
-	for(let i=0;i<t.getChildCount();i++) {
-		list.push(t.getChild(i));
-	}
-	return list;
-};
-
-/**
- * Return a list of all ancestors of this node.  The first node of
- * list is the root and the last is the parent of this node.
- */
-Trees.getAncestors = function(t) {
-    let ancestors = [];
-    t = t.getParent();
-    while(t!==null) {
-        ancestors = [t].concat(ancestors);
-        t = t.getParent();
-    }
-    return ancestors;
-};
-
-Trees.findAllTokenNodes = function(t, ttype) {
-    return Trees.findAllNodes(t, ttype, true);
-};
-
-Trees.findAllRuleNodes = function(t, ruleIndex) {
-	return Trees.findAllNodes(t, ruleIndex, false);
-};
-
-Trees.findAllNodes = function(t, index, findTokens) {
-	const nodes = [];
-	Trees._findAllNodes(t, index, findTokens, nodes);
-	return nodes;
-};
-
-Trees._findAllNodes = function(t, index, findTokens, nodes) {
-	// check this node (the root) first
-	if(findTokens && (t instanceof TerminalNode)) {
-		if(t.symbol.type===index) {
-			nodes.push(t);
-		}
-	} else if(!findTokens && (t instanceof ParserRuleContext)) {
-		if(t.ruleIndex===index) {
-			nodes.push(t);
-		}
-	}
-	// check children
-	for(let i=0;i<t.getChildCount();i++) {
-		Trees._findAllNodes(t.getChild(i), index, findTokens, nodes);
-	}
-};
-
-Trees.descendants = function(t) {
-	let nodes = [t];
-    for(let i=0;i<t.getChildCount();i++) {
-        nodes = nodes.concat(Trees.descendants(t.getChild(i)));
-    }
-    return nodes;
-};
-
-
-exports.Trees = Trees;
+module.exports = {Trees};