PR feedback.

src/compiler/checker.ts

@@ -167,7 +167,7 @@ namespace ts {
 
         return checker;
 
-        function getEmitResolver(sourceFile: SourceFile, cancellationToken: CancellationTokenObject) {
+        function getEmitResolver(sourceFile: SourceFile, cancellationToken: CancellationToken) {
             // Ensure we have all the type information in place for this file so that all the
             // emitter questions of this resolver will return the right information.
             getDiagnostics(sourceFile, cancellationToken);
@@ -11681,8 +11681,8 @@ namespace ts {
             }
         }
 
-        var cancellationToken: CancellationTokenObject;
-        function getDiagnostics(sourceFile: SourceFile, ct: CancellationTokenObject): Diagnostic[] {
+        var cancellationToken: CancellationToken;
+        function getDiagnostics(sourceFile: SourceFile, ct: CancellationToken): Diagnostic[] {
             try {
                 // Record the cancellation token so it can be checked later on during checkSourceElement.
                 // Do this in a finally block so we can ensure that it gets reset back to nothing after

src/compiler/core.ts

@@ -798,25 +798,4 @@ namespace ts {
             Debug.assert(false, message);
         }
     }
-}
-
-namespace ts {
-    export class OperationCanceledException { }
-
-    export class CancellationTokenObject {
-        public static None: CancellationTokenObject = new CancellationTokenObject(null)
-
-        constructor(private cancellationToken: CancellationToken) {
-        }
-
-        public isCancellationRequested() {
-            return this.cancellationToken && this.cancellationToken.isCancellationRequested();
-        }
-
-        public throwIfCancellationRequested(): void {
-            if (this.isCancellationRequested()) {
-                throw new OperationCanceledException();
-            }
-        }
-    }
 }

src/compiler/program.ts

@@ -104,7 +104,7 @@ namespace ts {
         };
     }
 
-    export function getPreEmitDiagnostics(program: Program, sourceFile?: SourceFile, cancellationToken?: CancellationTokenObject): Diagnostic[] {
+    export function getPreEmitDiagnostics(program: Program, sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[] {
         let diagnostics = program.getOptionsDiagnostics(cancellationToken).concat(
                           program.getSyntacticDiagnostics(sourceFile, cancellationToken),
                           program.getGlobalDiagnostics(cancellationToken),
@@ -233,11 +233,11 @@ namespace ts {
             return noDiagnosticsTypeChecker || (noDiagnosticsTypeChecker = createTypeChecker(program, /*produceDiagnostics:*/ false));
         }
 
-        function emit(sourceFile?: SourceFile, writeFileCallback?: WriteFileCallback, cancellationToken?: CancellationTokenObject): EmitResult {
+        function emit(sourceFile?: SourceFile, writeFileCallback?: WriteFileCallback, cancellationToken?: CancellationToken): EmitResult {
             return runWithCancellationToken(() => emitWorker(this, sourceFile, writeFileCallback, cancellationToken));
         }
 
-        function emitWorker(program: Program, sourceFile: SourceFile, writeFileCallback: WriteFileCallback, cancellationToken: CancellationTokenObject): EmitResult {
+        function emitWorker(program: Program, sourceFile: SourceFile, writeFileCallback: WriteFileCallback, cancellationToken: CancellationToken): EmitResult {
             // If the noEmitOnError flag is set, then check if we have any errors so far.  If so,
             // immediately bail out.  Note that we pass 'undefined' for 'sourceFile' so that we 
             // get any preEmit diagnostics, not just the ones 
@@ -272,8 +272,8 @@ namespace ts {
 
         function getDiagnosticsHelper(
                 sourceFile: SourceFile,
-                getDiagnostics: (sourceFile: SourceFile, cancellationToken: CancellationTokenObject) => Diagnostic[],
-                cancellationToken: CancellationTokenObject): Diagnostic[] {
+                getDiagnostics: (sourceFile: SourceFile, cancellationToken: CancellationToken) => Diagnostic[],
+                cancellationToken: CancellationToken): Diagnostic[] {
             if (sourceFile) {
                 return getDiagnostics(sourceFile, cancellationToken);
             }
@@ -289,19 +289,19 @@ namespace ts {
             return sortAndDeduplicateDiagnostics(allDiagnostics);
         }
 
-        function getSyntacticDiagnostics(sourceFile: SourceFile, cancellationToken: CancellationTokenObject): Diagnostic[] {
+        function getSyntacticDiagnostics(sourceFile: SourceFile, cancellationToken: CancellationToken): Diagnostic[] {
             return getDiagnosticsHelper(sourceFile, getSyntacticDiagnosticsForFile, cancellationToken);
         }
 
-        function getSemanticDiagnostics(sourceFile: SourceFile, cancellationToken: CancellationTokenObject): Diagnostic[] {
+        function getSemanticDiagnostics(sourceFile: SourceFile, cancellationToken: CancellationToken): Diagnostic[] {
             return getDiagnosticsHelper(sourceFile, getSemanticDiagnosticsForFile, cancellationToken);
         }
 
-        function getDeclarationDiagnostics(sourceFile: SourceFile, cancellationToken: CancellationTokenObject): Diagnostic[] {
+        function getDeclarationDiagnostics(sourceFile: SourceFile, cancellationToken: CancellationToken): Diagnostic[] {
             return getDiagnosticsHelper(sourceFile, getDeclarationDiagnosticsForFile, cancellationToken);
         }
 
-        function getSyntacticDiagnosticsForFile(sourceFile: SourceFile, cancellationToken: CancellationTokenObject): Diagnostic[] {
+        function getSyntacticDiagnosticsForFile(sourceFile: SourceFile, cancellationToken: CancellationToken): Diagnostic[] {
             return sourceFile.parseDiagnostics;
         }
 
@@ -321,7 +321,7 @@ namespace ts {
             }
         }
 
-        function getSemanticDiagnosticsForFile(sourceFile: SourceFile, cancellationToken: CancellationTokenObject): Diagnostic[] {
+        function getSemanticDiagnosticsForFile(sourceFile: SourceFile, cancellationToken: CancellationToken): Diagnostic[] {
             return runWithCancellationToken(() => {
                 let typeChecker = getDiagnosticsProducingTypeChecker();
 
@@ -334,7 +334,7 @@ namespace ts {
             });
         }
 
-        function getDeclarationDiagnosticsForFile(sourceFile: SourceFile, cancellationToken: CancellationTokenObject): Diagnostic[] {
+        function getDeclarationDiagnosticsForFile(sourceFile: SourceFile, cancellationToken: CancellationToken): Diagnostic[] {
             return runWithCancellationToken(() => {
                 if (!isDeclarationFile(sourceFile)) {
                     let resolver = getDiagnosticsProducingTypeChecker().getEmitResolver(sourceFile, cancellationToken);

src/compiler/types.ts

@@ -1210,13 +1210,13 @@ namespace ts {
          * used for writing the JavaScript and declaration files.  Otherwise, the writeFile parameter
          * will be invoked when writing the JavaScript and declaration files.
          */
-        emit(targetSourceFile?: SourceFile, writeFile?: WriteFileCallback, cancellationToken?: CancellationTokenObject): EmitResult;
+        emit(targetSourceFile?: SourceFile, writeFile?: WriteFileCallback, cancellationToken?: CancellationToken): EmitResult;
 
-        getOptionsDiagnostics(cancellationToken?: CancellationTokenObject): Diagnostic[];
-        getGlobalDiagnostics(cancellationToken?: CancellationTokenObject): Diagnostic[];
-        getSyntacticDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationTokenObject): Diagnostic[];
-        getSemanticDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationTokenObject): Diagnostic[];
-        getDeclarationDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationTokenObject): Diagnostic[];
+        getOptionsDiagnostics(cancellationToken?: CancellationToken): Diagnostic[];
+        getGlobalDiagnostics(cancellationToken?: CancellationToken): Diagnostic[];
+        getSyntacticDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
+        getSemanticDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
+        getDeclarationDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
 
         /** 
          * Gets a type checker that can be used to semantically analyze source fils in the program.
@@ -1324,9 +1324,9 @@ namespace ts {
         getExportsOfModule(moduleSymbol: Symbol): Symbol[];
 
         // Should not be called directly.  Should only be accessed through the Program instance.
-        /* @internal */ getDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationTokenObject): Diagnostic[];
+        /* @internal */ getDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
         /* @internal */ getGlobalDiagnostics(): Diagnostic[];
-        /* @internal */ getEmitResolver(sourceFile?: SourceFile, cancellationToken?: CancellationTokenObject): EmitResolver;
+        /* @internal */ getEmitResolver(sourceFile?: SourceFile, cancellationToken?: CancellationToken): EmitResolver;
 
         /* @internal */ getNodeCount(): number;
         /* @internal */ getIdentifierCount(): number;
@@ -2052,14 +2052,18 @@ namespace ts {
         verticalTab = 0x0B,           // \v
     }
 
+    export class OperationCanceledException { }
+
     export interface CancellationToken {
         isCancellationRequested(): boolean;
+
+        /** @throws OperationCanceledException if isCancellationRequested is true */
+        throwIfCancellationRequested(): void;
     }
 
     export interface CompilerHost {
         getSourceFile(fileName: string, languageVersion: ScriptTarget, onError?: (message: string) => void): SourceFile;
         getDefaultLibFileName(options: CompilerOptions): string;
-        getCancellationToken? (): CancellationToken;
         writeFile: WriteFileCallback;
         getCurrentDirectory(): string;
         getCanonicalFileName(fileName: string): string;

src/harness/fourslash.ts

@@ -190,14 +190,14 @@ module FourSlash {
         return "\nMarker: " + currentTestState.lastKnownMarker + "\nChecking: " + msg + "\n\n";
     }
 
-    export class TestCancellationToken implements ts.CancellationToken {
+    export class TestCancellationToken implements ts.HostCancellationToken {
         // 0 - cancelled
         // >0 - not cancelled 
         // <0 - not cancelled and value denotes number of isCancellationRequested after which token become cancelled
-        private static NotCancelled: number = -1;
-        private numberOfCallsBeforeCancellation: number = TestCancellationToken.NotCancelled;
-        public isCancellationRequested(): boolean {
+        private static NotCanceled: number = -1;
+        private numberOfCallsBeforeCancellation: number = TestCancellationToken.NotCanceled;
 
+        public isCancellationRequested(): boolean {
             if (this.numberOfCallsBeforeCancellation < 0) {
                 return false;
             }
@@ -216,7 +216,7 @@ module FourSlash {
         }
 
         public resetCancelled(): void {
-            this.numberOfCallsBeforeCancellation = TestCancellationToken.NotCancelled;
+            this.numberOfCallsBeforeCancellation = TestCancellationToken.NotCanceled;
         }
     }
 

src/harness/harnessLanguageService.ts

@@ -103,14 +103,11 @@ module Harness.LanguageService {
         }
     }
 
-    class CancellationToken {
-        public static None: CancellationToken = new CancellationToken(null);
-
-        constructor(private cancellationToken: ts.CancellationToken) {
-        }
+    class DefaultHostCancellationToken implements ts.HostCancellationToken {
+        public static Instance = new DefaultHostCancellationToken();
 
         public isCancellationRequested() {
-            return this.cancellationToken && this.cancellationToken.isCancellationRequested();
+            return false;
         }
     }
 
@@ -124,8 +121,8 @@ module Harness.LanguageService {
     export class LanguageServiceAdapterHost  {
         protected fileNameToScript: ts.Map<ScriptInfo> = {};
         
-        constructor(protected cancellationToken: ts.CancellationToken = CancellationToken.None,
-            protected settings = ts.getDefaultCompilerOptions()) { 
+        constructor(protected cancellationToken = DefaultHostCancellationToken.Instance,
+                    protected settings = ts.getDefaultCompilerOptions()) { 
         }
 
         public getNewLine(): string {
@@ -173,8 +170,8 @@ module Harness.LanguageService {
 
     /// Native adapter
     class NativeLanguageServiceHost extends LanguageServiceAdapterHost implements ts.LanguageServiceHost { 
-        getCompilationSettings(): ts.CompilerOptions { return this.settings; }
-        getCancellationToken(): ts.CancellationToken { return this.cancellationToken; }
+        getCompilationSettings() { return this.settings; }
+        getCancellationToken() { return this.cancellationToken; }
         getCurrentDirectory(): string { return ""; }
         getDefaultLibFileName(): string { return ""; }
         getScriptFileNames(): string[] { return this.getFilenames(); }
@@ -194,7 +191,7 @@ module Harness.LanguageService {
 
     export class NativeLanugageServiceAdapter implements LanguageServiceAdapter {
         private host: NativeLanguageServiceHost;
-        constructor(cancellationToken?: ts.CancellationToken, options?: ts.CompilerOptions) { 
+        constructor(cancellationToken?: ts.HostCancellationToken, options?: ts.CompilerOptions) { 
             this.host = new NativeLanguageServiceHost(cancellationToken, options);
         }
         getHost() { return this.host; }
@@ -206,7 +203,7 @@ module Harness.LanguageService {
     /// Shim adapter
     class ShimLanguageServiceHost extends LanguageServiceAdapterHost implements ts.LanguageServiceShimHost, ts.CoreServicesShimHost {
         private nativeHost: NativeLanguageServiceHost;
-        constructor(cancellationToken?: ts.CancellationToken, options?: ts.CompilerOptions) {
+        constructor(cancellationToken?: ts.HostCancellationToken, options?: ts.CompilerOptions) {
             super(cancellationToken, options);
             this.nativeHost = new NativeLanguageServiceHost(cancellationToken, options);
         }
@@ -218,7 +215,7 @@ module Harness.LanguageService {
         positionToLineAndCharacter(fileName: string, position: number): ts.LineAndCharacter { return this.nativeHost.positionToLineAndCharacter(fileName, position); }
 
         getCompilationSettings(): string { return JSON.stringify(this.nativeHost.getCompilationSettings()); }
-        getCancellationToken(): ts.CancellationToken { return this.nativeHost.getCancellationToken(); }
+        getCancellationToken(): ts.HostCancellationToken { return this.nativeHost.getCancellationToken(); }
         getCurrentDirectory(): string { return this.nativeHost.getCurrentDirectory(); }
         getDefaultLibFileName(): string { return this.nativeHost.getDefaultLibFileName(); }
         getScriptFileNames(): string { return JSON.stringify(this.nativeHost.getScriptFileNames()); }
@@ -399,7 +396,7 @@ module Harness.LanguageService {
     export class ShimLanugageServiceAdapter implements LanguageServiceAdapter {
         private host: ShimLanguageServiceHost;
         private factory: ts.TypeScriptServicesFactory;
-        constructor(cancellationToken?: ts.CancellationToken, options?: ts.CompilerOptions) {
+        constructor(cancellationToken?: ts.HostCancellationToken, options?: ts.CompilerOptions) {
             this.host = new ShimLanguageServiceHost(cancellationToken, options);
             this.factory = new TypeScript.Services.TypeScriptServicesFactory();
         }
@@ -446,7 +443,7 @@ module Harness.LanguageService {
     class SessionClientHost extends NativeLanguageServiceHost implements ts.server.SessionClientHost { 
         private client: ts.server.SessionClient;
 
-        constructor(cancellationToken: ts.CancellationToken, settings: ts.CompilerOptions) {
+        constructor(cancellationToken: ts.HostCancellationToken, settings: ts.CompilerOptions) {
             super(cancellationToken, settings);
         }
 
@@ -575,7 +572,7 @@ module Harness.LanguageService {
     export class ServerLanugageServiceAdapter implements LanguageServiceAdapter {
         private host: SessionClientHost;
         private client: ts.server.SessionClient;
-        constructor(cancellationToken?: ts.CancellationToken, options?: ts.CompilerOptions) {
+        constructor(cancellationToken?: ts.HostCancellationToken, options?: ts.CompilerOptions) {
             // This is the main host that tests use to direct tests
             var clientHost = new SessionClientHost(cancellationToken, options);
             var client = new ts.server.SessionClient(clientHost);

src/services/navigateTo.ts

@@ -2,7 +2,7 @@
 namespace ts.NavigateTo {
     type RawNavigateToItem = { name: string; fileName: string; matchKind: PatternMatchKind; isCaseSensitive: boolean; declaration: Declaration };
 
-    export function getNavigateToItems(program: Program, cancellationToken: CancellationTokenObject, searchValue: string, maxResultCount: number): NavigateToItem[] {
+    export function getNavigateToItems(program: Program, cancellationToken: CancellationToken, searchValue: string, maxResultCount: number): NavigateToItem[] {
         let patternMatcher = createPatternMatcher(searchValue);
         let rawItems: RawNavigateToItem[] = [];
 

src/services/services.ts

@@ -944,6 +944,10 @@ namespace ts {
         }
     }
 
+    export interface HostCancellationToken {
+        isCancellationRequested(): boolean;
+    }
+
     //
     // Public interface of the host of a language service instance.
     //
@@ -955,7 +959,7 @@ namespace ts {
         getScriptVersion(fileName: string): string;
         getScriptSnapshot(fileName: string): IScriptSnapshot;
         getLocalizedDiagnosticMessages?(): any;
-        getCancellationToken?(): CancellationToken;
+        getCancellationToken?(): HostCancellationToken;
         getCurrentDirectory(): string;
         getDefaultLibFileName(options: CompilerOptions): string;
         log? (s: string): void;
@@ -2379,6 +2383,21 @@ namespace ts {
         return ScriptElementKind.unknown;
     }
 
+    class CancellationTokenObject implements CancellationToken {
+        constructor(private cancellationToken: HostCancellationToken) {
+        }
+
+        public isCancellationRequested() {
+            return this.cancellationToken && this.cancellationToken.isCancellationRequested();
+        }
+
+        public throwIfCancellationRequested(): void {
+            if (this.isCancellationRequested()) {
+                throw new OperationCanceledException();
+            }
+        }
+    }
+
     export function createLanguageService(host: LanguageServiceHost, documentRegistry: DocumentRegistry = createDocumentRegistry()): LanguageService {
         let syntaxTreeCache: SyntaxTreeCache = new SyntaxTreeCache(host);
         let ruleProvider: formatting.RulesProvider;

src/services/shims.ts

@@ -51,7 +51,7 @@ namespace ts {
         getScriptVersion(fileName: string): string;
         getScriptSnapshot(fileName: string): ScriptSnapshotShim;
         getLocalizedDiagnosticMessages(): string;
-        getCancellationToken(): CancellationToken;
+        getCancellationToken(): HostCancellationToken;
         getCurrentDirectory(): string;
         getDefaultLibFileName(options: string): string;
         getNewLine?(): string;
@@ -326,7 +326,7 @@ namespace ts {
             }
         }
 
-        public getCancellationToken(): CancellationToken {
+        public getCancellationToken(): HostCancellationToken {
             return this.shimHost.getCancellationToken();
         }
 

src/services/signatureHelp.ts

@@ -178,7 +178,7 @@ namespace ts.SignatureHelp {
         argumentCount: number;
     }
 
-    export function getSignatureHelpItems(program: Program, sourceFile: SourceFile, position: number, cancellationToken: CancellationTokenObject): SignatureHelpItems {
+    export function getSignatureHelpItems(program: Program, sourceFile: SourceFile, position: number, cancellationToken: CancellationToken): SignatureHelpItems {
         let typeChecker = program.getTypeChecker();
 
         // Decide whether to show signature help