Use native generators/iterables, remove helper cruft (#51921)

Author: jakebailey

src/compiler/builderState.ts

@@ -108,7 +108,7 @@ export namespace BuilderState {
     export interface ReadonlyManyToManyPathMap {
         getKeys(v: Path): ReadonlySet<Path> | undefined;
         getValues(k: Path): ReadonlySet<Path> | undefined;
-        keys(): Iterator<Path>;
+        keys(): IterableIterator<Path>;
     }
 
     export interface ManyToManyPathMap extends ReadonlyManyToManyPathMap {
@@ -521,9 +521,8 @@ export namespace BuilderState {
                 seenMap.add(path);
                 const references = state.referencedMap.getValues(path);
                 if (references) {
-                    const iterator = references.keys();
-                    for (let iterResult = iterator.next(); !iterResult.done; iterResult = iterator.next()) {
-                        queue.push(iterResult.value);
+                    for (const key of references.keys()) {
+                        queue.push(key);
                     }
                 }
             }

src/compiler/checker.ts

@@ -181,6 +181,7 @@ import {
     first,
     firstDefined,
     firstOrUndefined,
+    firstOrUndefinedIterator,
     flatMap,
     flatten,
     FlowArrayMutation,
@@ -259,7 +260,6 @@ import {
     getEmitScriptTarget,
     getEnclosingBlockScopeContainer,
     getEntityNameFromTypeNode,
-    getEntries,
     getErrorSpanForNode,
     getEscapedTextOfIdentifierOrLiteral,
     getESModuleInterop,
@@ -347,8 +347,8 @@ import {
     hasAccessorModifier,
     hasAmbientModifier,
     hasContextSensitiveParameters,
-    hasDecorators,
     HasDecorators,
+    hasDecorators,
     hasDynamicName,
     hasEffectiveModifier,
     hasEffectiveModifiers,
@@ -357,8 +357,8 @@ import {
     hasExtension,
     HasIllegalDecorators,
     HasIllegalModifiers,
-    hasInitializer,
     HasInitializer,
+    hasInitializer,
     hasJSDocNodes,
     hasJSDocParameterTags,
     hasJsonModuleEmitEnabled,
@@ -926,7 +926,6 @@ import {
     stripQuotes,
     StructuredType,
     SubstitutionType,
-    sum,
     SuperCall,
     SwitchStatement,
     Symbol,
@@ -1180,7 +1179,7 @@ export const enum TypeFacts {
     AndFactsMask = All & ~OrFactsMask,
 }
 
-const typeofNEFacts: ReadonlyMap<string, TypeFacts> = new Map(getEntries({
+const typeofNEFacts: ReadonlyMap<string, TypeFacts> = new Map(Object.entries({
     string: TypeFacts.TypeofNEString,
     number: TypeFacts.TypeofNENumber,
     bigint: TypeFacts.TypeofNEBigInt,
@@ -1301,7 +1300,7 @@ const enum IntrinsicTypeKind {
     Uncapitalize
 }
 
-const intrinsicTypeKinds: ReadonlyMap<string, IntrinsicTypeKind> = new Map(getEntries({
+const intrinsicTypeKinds: ReadonlyMap<string, IntrinsicTypeKind> = new Map(Object.entries({
     Uppercase: IntrinsicTypeKind.Uppercase,
     Lowercase: IntrinsicTypeKind.Lowercase,
     Capitalize: IntrinsicTypeKind.Capitalize,
@@ -1436,9 +1435,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     // extra cost of calling `getParseTreeNode` when calling these functions from inside the
     // checker.
     const checker: TypeChecker = {
-        getNodeCount: () => sum(host.getSourceFiles(), "nodeCount"),
-        getIdentifierCount: () => sum(host.getSourceFiles(), "identifierCount"),
-        getSymbolCount: () => sum(host.getSourceFiles(), "symbolCount") + symbolCount,
+        getNodeCount: () => reduceLeft(host.getSourceFiles(), (n, s) => n + s.nodeCount, 0),
+        getIdentifierCount: () => reduceLeft(host.getSourceFiles(), (n, s) => n + s.identifierCount, 0),
+        getSymbolCount: () => reduceLeft(host.getSourceFiles(), (n, s) => n + s.symbolCount, symbolCount),
         getTypeCount: () => typeCount,
         getInstantiationCount: () => totalInstantiationCount,
         getRelationCacheSizes: () => ({
@@ -13649,7 +13648,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             isUnion &&
             (propSet || checkFlags & CheckFlags.Partial) &&
             checkFlags & (CheckFlags.ContainsPrivate | CheckFlags.ContainsProtected) &&
-            !(propSet && getCommonDeclarationsOfSymbols(arrayFrom(propSet.values())))
+            !(propSet && getCommonDeclarationsOfSymbols(propSet.values()))
         ) {
             // No property was found, or, in a union, a property has a private or protected declaration in one
             // constituent, but is missing or has a different declaration in another constituent.
@@ -13757,7 +13756,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         return property;
     }
 
-    function getCommonDeclarationsOfSymbols(symbols: readonly Symbol[]) {
+    function getCommonDeclarationsOfSymbols(symbols: Iterable<Symbol>) {
         let commonDeclarations: Set<Node> | undefined;
         for (const symbol of symbols) {
             if (!symbol.declarations) {
@@ -19009,8 +19008,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     ) {
         // Assignability failure - check each prop individually, and if that fails, fall back on the bad error span
         let reportedError = false;
-        for (let status = iterator.next(); !status.done; status = iterator.next()) {
-            const { errorNode: prop, innerExpression: next, nameType, errorMessage } = status.value;
+        for (const value of iterator) {
+            const { errorNode: prop, innerExpression: next, nameType, errorMessage } = value;
             let targetPropType = getBestMatchIndexedAccessTypeOrUndefined(source, target, nameType);
             if (!targetPropType || targetPropType.flags & TypeFlags.IndexedAccess) continue; // Don't elaborate on indexes on generic variables
             let sourcePropType = getIndexedAccessTypeOrUndefined(source, nameType);
@@ -23563,8 +23562,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     }
 
     function getUnmatchedProperty(source: Type, target: Type, requireOptionalProperties: boolean, matchDiscriminantProperties: boolean): Symbol | undefined {
-        const result = getUnmatchedProperties(source, target, requireOptionalProperties, matchDiscriminantProperties).next();
-        if (!result.done) return result.value;
+        return firstOrUndefinedIterator(getUnmatchedProperties(source, target, requireOptionalProperties, matchDiscriminantProperties));
     }
 
     function tupleTypesDefinitelyUnrelated(source: TupleTypeReference, target: TupleTypeReference) {

src/compiler/commandLineParser.ts

@@ -41,12 +41,12 @@ import {
     find,
     findIndex,
     firstDefined,
+    firstOrUndefinedIterator,
     flatten,
     forEach,
     forEachEntry,
     getBaseFileName,
     getDirectoryPath,
-    getEntries,
     getFileMatcherPatterns,
     getLocaleSpecificMessage,
     getNormalizedAbsolutePath,
@@ -128,7 +128,7 @@ export const compileOnSaveCommandLineOption: CommandLineOption = {
     defaultValueDescription: false,
 };
 
-const jsxOptionMap = new Map(getEntries({
+const jsxOptionMap = new Map(Object.entries({
     "preserve": JsxEmit.Preserve,
     "react-native": JsxEmit.ReactNative,
     "react": JsxEmit.React,
@@ -137,7 +137,7 @@ const jsxOptionMap = new Map(getEntries({
 }));
 
 /** @internal */
-export const inverseJsxOptionMap = new Map(arrayFrom(mapIterator(jsxOptionMap.entries(), ([key, value]: [string, JsxEmit]) => ["" + value, key] as const)));
+export const inverseJsxOptionMap = new Map(mapIterator(jsxOptionMap.entries(), ([key, value]: [string, JsxEmit]) => ["" + value, key] as const));
 
 // NOTE: The order here is important to default lib ordering as entries will have the same
 //       order in the generated program (see `getDefaultLibPriority` in program.ts). This
@@ -241,7 +241,7 @@ export const libMap = new Map(libEntries);
 export const optionsForWatch: CommandLineOption[] = [
     {
         name: "watchFile",
-        type: new Map(getEntries({
+        type: new Map(Object.entries({
             fixedpollinginterval: WatchFileKind.FixedPollingInterval,
             prioritypollinginterval: WatchFileKind.PriorityPollingInterval,
             dynamicprioritypolling: WatchFileKind.DynamicPriorityPolling,
@@ -255,7 +255,7 @@ export const optionsForWatch: CommandLineOption[] = [
     },
     {
         name: "watchDirectory",
-        type: new Map(getEntries({
+        type: new Map(Object.entries({
             usefsevents: WatchDirectoryKind.UseFsEvents,
             fixedpollinginterval: WatchDirectoryKind.FixedPollingInterval,
             dynamicprioritypolling: WatchDirectoryKind.DynamicPriorityPolling,
@@ -267,7 +267,7 @@ export const optionsForWatch: CommandLineOption[] = [
     },
     {
         name: "fallbackPolling",
-        type: new Map(getEntries({
+        type: new Map(Object.entries({
             fixedinterval: PollingWatchKind.FixedInterval,
             priorityinterval: PollingWatchKind.PriorityInterval,
             dynamicpriority: PollingWatchKind.DynamicPriority,
@@ -502,7 +502,7 @@ export const commonOptionsWithBuild: CommandLineOption[] = [
 export const targetOptionDeclaration: CommandLineOptionOfCustomType = {
     name: "target",
     shortName: "t",
-    type: new Map(getEntries({
+    type: new Map(Object.entries({
         es3: ScriptTarget.ES3,
         es5: ScriptTarget.ES5,
         es6: ScriptTarget.ES2015,
@@ -531,7 +531,7 @@ export const targetOptionDeclaration: CommandLineOptionOfCustomType = {
 export const moduleOptionDeclaration: CommandLineOptionOfCustomType = {
     name: "module",
     shortName: "m",
-    type: new Map(getEntries({
+    type: new Map(Object.entries({
         none: ModuleKind.None,
         commonjs: ModuleKind.CommonJS,
         amd: ModuleKind.AMD,
@@ -756,7 +756,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
     },
     {
         name: "importsNotUsedAsValues",
-        type: new Map(getEntries({
+        type: new Map(Object.entries({
             remove: ImportsNotUsedAsValues.Remove,
             preserve: ImportsNotUsedAsValues.Preserve,
             error: ImportsNotUsedAsValues.Error,
@@ -961,7 +961,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
     // Module Resolution
     {
         name: "moduleResolution",
-        type: new Map(getEntries({
+        type: new Map(Object.entries({
             // N.B. The first entry specifies the value shown in `tsc --init`
             node10: ModuleResolutionKind.Node10,
             node: ModuleResolutionKind.Node10,
@@ -1256,7 +1256,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
     },
     {
         name: "newLine",
-        type: new Map(getEntries({
+        type: new Map(Object.entries({
             crlf: NewLineKind.CarriageReturnLineFeed,
             lf: NewLineKind.LineFeed
         })),
@@ -1502,7 +1502,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
     },
     {
         name: "moduleDetection",
-        type: new Map(getEntries({
+        type: new Map(Object.entries({
             auto: ModuleDetectionKind.Auto,
             legacy: ModuleDetectionKind.Legacy,
             force: ModuleDetectionKind.Force,
@@ -4033,8 +4033,8 @@ function getDefaultValueForOption(option: CommandLineOption): {} {
         case "object":
             return {};
         default:
-            const iterResult = option.type.keys().next();
-            if (!iterResult.done) return iterResult.value;
+            const value = firstOrUndefinedIterator(option.type.keys());
+            if (value !== undefined) return value;
             return Debug.fail("Expected 'option.type' to have entries.");
     }
 }