initialize fields from constructor parameters

src/compiler/core.ts

@@ -775,7 +775,7 @@ namespace ts {
     };
 
     export interface ObjectAllocator {
-        getNodeConstructor(kind: SyntaxKind): new () => Node;
+        getNodeConstructor(kind: SyntaxKind): new (pos?: number, end?: number) => Node;
         getSymbolConstructor(): new (flags: SymbolFlags, name: string) => Symbol;
         getTypeConstructor(): new (checker: TypeChecker, flags: TypeFlags) => Type;
         getSignatureConstructor(): new (checker: TypeChecker) => Signature;
@@ -796,15 +796,13 @@ namespace ts {
 
     export let objectAllocator: ObjectAllocator = {
         getNodeConstructor: kind => {
-            function Node() {
-                this.pos = -1;
-                this.end = -1;
-                this.flags = 0;
+            function Node(pos: number, end: number) {
+                this.pos = pos;
+                this.end = end;
+                this.flags = NodeFlags.None;
                 this.parent = undefined;
             }
-            Node.prototype = {
-                kind: kind
-            };
+            Node.prototype = { kind };
             return <any>Node;
         },
         getSymbolConstructor: () => <any>Symbol,

src/compiler/parser.ts

@@ -2,15 +2,15 @@
 /// <reference path="utilities.ts"/>
 
 namespace ts {
-    let nodeConstructors = new Array<new () => Node>(SyntaxKind.Count);
+    let nodeConstructors = new Array<new (pos: number, end: number) => Node>(SyntaxKind.Count);
     /* @internal */ export let parseTime = 0;
 
-    export function getNodeConstructor(kind: SyntaxKind): new () => Node {
+    export function getNodeConstructor(kind: SyntaxKind): new (pos?: number, end?: number) => Node {
         return nodeConstructors[kind] || (nodeConstructors[kind] = objectAllocator.getNodeConstructor(kind));
     }
 
-    export function createNode(kind: SyntaxKind): Node {
-        return new (getNodeConstructor(kind))();
+    export function createNode(kind: SyntaxKind, pos?: number, end?: number): Node {
+        return new (getNodeConstructor(kind))(pos, end);
     }
 
     function visitNode<T>(cbNode: (node: Node) => T, node: Node): T {
@@ -993,14 +993,10 @@ namespace ts {
 
         function createNode(kind: SyntaxKind, pos?: number): Node {
             nodeCount++;
-            let node = new (nodeConstructors[kind] || (nodeConstructors[kind] = objectAllocator.getNodeConstructor(kind)))();
             if (!(pos >= 0)) {
                 pos = scanner.getStartPos();
             }
-
-            node.pos = pos;
-            node.end = pos;
-            return node;
+            return new (nodeConstructors[kind] || (nodeConstructors[kind] = objectAllocator.getNodeConstructor(kind)))(pos, pos);
         }
 
         function finishNode<T extends Node>(node: T, end?: number): T {

src/compiler/types.ts

@@ -361,6 +361,7 @@ namespace ts {
     }
 
     export const enum NodeFlags {
+        None =              0,
         Export =            0x00000001,  // Declarations
         Ambient =           0x00000002,  // Declarations
         Public =            0x00000010,  // Property/Method

src/compiler/utilities.ts

@@ -1505,7 +1505,7 @@ namespace ts {
     }
 
     export function createSynthesizedNode(kind: SyntaxKind, startsOnNewLine?: boolean): Node {
-        let node = <SynthesizedNode>createNode(kind);
+        let node = <SynthesizedNode>createNode(kind, /* pos */ -1, /* end */ -1);
         node.startsOnNewLine = startsOnNewLine;
         return node;
     }

src/harness/harness.ts

@@ -274,7 +274,9 @@ namespace Utils {
 
                     case "flags":
                         // Print out flags with their enum names.
-                        o[propertyName] = getNodeFlagName(n.flags);
+                        if (n.flags) {
+                            o[propertyName] = getNodeFlagName(n.flags);
+                        }
                         break;
 
                     case "parserContextFlags":

src/services/services.ts

@@ -174,9 +174,7 @@ namespace ts {
     let jsDocCompletionEntries: CompletionEntry[];
 
     function createNode(kind: SyntaxKind, pos: number, end: number, flags: NodeFlags, parent?: Node): NodeObject {
-        let node = <NodeObject> new (getNodeConstructor(kind))();
-        node.pos = pos;
-        node.end = end;
+        let node = <NodeObject> new (getNodeConstructor(kind))(pos, end);
         node.flags = flags;
         node.parent = parent;
         return node;
@@ -7967,14 +7965,14 @@ namespace ts {
     function initializeServices() {
         objectAllocator = {
             getNodeConstructor: kind => {
-                function Node() {
+                function Node(pos: number, end: number) {
+                    this.pos = pos;
+                    this.end = end;
+                    this.flags = NodeFlags.None;
+                    this.parent = undefined;
                 }
                 let proto = kind === SyntaxKind.SourceFile ? new SourceFileObject() : new NodeObject();
                 proto.kind = kind;
-                proto.pos = -1;
-                proto.end = -1;
-                proto.flags = 0;
-                proto.parent = undefined;
                 Node.prototype = proto;
                 return <any>Node;
             },