import {

__String,

arrayToNumericMap,

CancellationToken,

CharacterCodes,

ClassDeclaration,

ClassificationInfo,

ClassificationResult,

Classifications,

ClassificationType,

ClassificationTypeNames,

ClassifiedSpan,

Classifier,

commentPragmas,

couldStartTrivia,

createScanner,

createTextSpan,

Debug,

decodedTextSpanIntersectsWith,

EndOfLineState,

EnumDeclaration,

getMeaningFromLocation,

getModuleInstanceState,

getTypeArgumentOrTypeParameterList,

HasJSDoc,

InterfaceDeclaration,

isAccessibilityModifier,

isConstTypeReference,

isIdentifier,

isJSDoc,

isKeyword,

isLineBreak,

isModuleDeclaration,

isPunctuation,

isTemplateLiteralKind,

isThisIdentifier,

isToken,

isTrivia,

JSDoc,

JSDocAugmentsTag,

JSDocCallbackTag,

JSDocEnumTag,

JSDocImplementsTag,

JSDocParameterTag,

JSDocPropertyTag,

JSDocReturnTag,

JSDocSeeTag,

JSDocTemplateTag,

JSDocThisTag,

JSDocThrowsTag,

JSDocTypedefTag,

JSDocTypeTag,

JsxAttribute,

JsxClosingElement,

JsxOpeningElement,

JsxSelfClosingElement,

lastOrUndefined,

ModuleDeclaration,

ModuleInstanceState,

Node,

nodeIsMissing,

ParameterDeclaration,

parseIsolatedJSDocComment,

Scanner,

ScriptTarget,

SemanticMeaning,

setParent,

some,

SourceFile,

Symbol,

SymbolFlags,

SyntaxKind,

TextSpan,

textSpanIntersectsWith,

TokenClass,

TypeChecker,

TypeParameterDeclaration,

} from "./_namespaces/ts.js";

/** The classifier is used for syntactic highlighting in editors via the TSServer */

export function createClassifier(): Classifier {

const scanner = createScanner(ScriptTarget.Latest, /*skipTrivia*/ false);

function getClassificationsForLine(text: string, lexState: EndOfLineState, syntacticClassifierAbsent: boolean): ClassificationResult {

return convertClassificationsToResult(getEncodedLexicalClassifications(text, lexState, syntacticClassifierAbsent), text);

}

// If there is a syntactic classifier ('syntacticClassifierAbsent' is false),

// we will be more conservative in order to avoid conflicting with the syntactic classifier.

function getEncodedLexicalClassifications(text: string, lexState: EndOfLineState, syntacticClassifierAbsent: boolean): Classifications {

let token = SyntaxKind.Unknown;

let lastNonTriviaToken = SyntaxKind.Unknown;

// Just a stack of TemplateHeads and OpenCurlyBraces, used to perform rudimentary (inexact)

// classification on template strings. Because of the context free nature of templates,

// the only precise way to classify a template portion would be by propagating the stack across

// lines, just as we do with the end-of-line state. However, this is a burden for implementers,

// and the behavior is entirely subsumed by the syntactic classifier anyway, so we instead

// flatten any nesting when the template stack is non-empty and encode it in the end-of-line state.

// Situations in which this fails are

// 1) When template strings are nested across different lines:

// `hello ${ `world

// ` }`

//

// Where on the second line, you will get the closing of a template,

// a closing curly, and a new template.

//

// 2) When substitution expressions have curly braces and the curly brace falls on the next line:

// `hello ${ () => {

// return "world" } } `

//

// Where on the second line, you will get the 'return' keyword,

// a string literal, and a template end consisting of '} } `'.

const templateStack: SyntaxKind[] = [];

const { prefix, pushTemplate } = getPrefixFromLexState(lexState);

text = prefix + text;

const offset = prefix.length;

if (pushTemplate) {

templateStack.push(SyntaxKind.TemplateHead);

}

scanner.setText(text);

let endOfLineState = EndOfLineState.None;

const spans: number[] = [];

// We can run into an unfortunate interaction between the lexical and syntactic classifier

// when the user is typing something generic. Consider the case where the user types:

//

// Foo<number

//

// From the lexical classifier's perspective, 'number' is a keyword, and so the word will

// be classified as such. However, from the syntactic classifier's tree-based perspective

// this is simply an expression with the identifier 'number' on the RHS of the less than

// token. So the classification will go back to being an identifier. The moment the user

// types again, number will become a keyword, then an identifier, etc. etc.

//

// To try to avoid this problem, we avoid classifying contextual keywords as keywords

// when the user is potentially typing something generic. We just can't do a good enough

// job at the lexical level, and so well leave it up to the syntactic classifier to make

// the determination.

//

// In order to determine if the user is potentially typing something generic, we use a

// weak heuristic where we track < and > tokens. It's a weak heuristic, but should

// work well enough in practice.

let angleBracketStack = 0;

do {

token = scanner.scan();

if (!isTrivia(token)) {

handleToken();

lastNonTriviaToken = token;

}

const end = scanner.getTokenEnd();

pushEncodedClassification(scanner.getTokenStart(), end, offset, classFromKind(token), spans);

if (end >= text.length) {

const end = getNewEndOfLineState(scanner, token, lastOrUndefined(templateStack));

if (end !== undefined) {

endOfLineState = end;

}

}

}

while (token !== SyntaxKind.EndOfFileToken);

function handleToken(): void {

switch (token) {

case SyntaxKind.SlashToken:

case SyntaxKind.SlashEqualsToken:

if (!noRegexTable[lastNonTriviaToken] && scanner.reScanSlashToken() === SyntaxKind.RegularExpressionLiteral) {

token = SyntaxKind.RegularExpressionLiteral;

}

break;

case SyntaxKind.LessThanToken:

if (lastNonTriviaToken === SyntaxKind.Identifier) {

// Could be the start of something generic. Keep track of that by bumping

// up the current count of generic contexts we may be in.

angleBracketStack++;

}

break;

case SyntaxKind.GreaterThanToken:

if (angleBracketStack > 0) {

// If we think we're currently in something generic, then mark that that

// generic entity is complete.

angleBracketStack--;

}

break;

case SyntaxKind.AnyKeyword:

case SyntaxKind.StringKeyword:

case SyntaxKind.NumberKeyword:

case SyntaxKind.BooleanKeyword:

case SyntaxKind.SymbolKeyword:

if (angleBracketStack > 0 && !syntacticClassifierAbsent) {

// If it looks like we're could be in something generic, don't classify this

// as a keyword. We may just get overwritten by the syntactic classifier,

// causing a noisy experience for the user.

token = SyntaxKind.Identifier;

}

break;

case SyntaxKind.TemplateHead:

templateStack.push(token);

break;

case SyntaxKind.OpenBraceToken:

// If we don't have anything on the template stack,

// then we aren't trying to keep track of a previously scanned template head.

if (templateStack.length > 0) {

templateStack.push(token);

}

break;

case SyntaxKind.CloseBraceToken:

// If we don't have anything on the template stack,

// then we aren't trying to keep track of a previously scanned template head.

if (templateStack.length > 0) {

const lastTemplateStackToken = lastOrUndefined(templateStack);

if (lastTemplateStackToken === SyntaxKind.TemplateHead) {

token = scanner.reScanTemplateToken(/*isTaggedTemplate*/ false);

// Only pop on a TemplateTail; a TemplateMiddle indicates there is more for us.

if (token === SyntaxKind.TemplateTail) {

templateStack.pop();

}

else {

Debug.assertEqual(token, SyntaxKind.TemplateMiddle, "Should have been a template middle.");

}

}

else {

Debug.assertEqual(lastTemplateStackToken, SyntaxKind.OpenBraceToken, "Should have been an open brace");

templateStack.pop();

}

}

break;

default:

if (!isKeyword(token)) {

break;

}

if (lastNonTriviaToken === SyntaxKind.DotToken) {

token = SyntaxKind.Identifier;

}

else if (isKeyword(lastNonTriviaToken) && isKeyword(token) && !canFollow(lastNonTriviaToken, token)) {

// We have two keywords in a row. Only treat the second as a keyword if

// it's a sequence that could legally occur in the language. Otherwise

// treat it as an identifier. This way, if someone writes "private var"

// we recognize that 'var' is actually an identifier here.

token = SyntaxKind.Identifier;

}

}

}

return { endOfLineState, spans };

}

return { getClassificationsForLine, getEncodedLexicalClassifications };

}

/// We do not have a full parser support to know when we should parse a regex or not

/// If we consider every slash token to be a regex, we could be missing cases like "1/2/3", where

/// we have a series of divide operator. this list allows us to be more accurate by ruling out

/// locations where a regexp cannot exist.

const noRegexTable: true[] = arrayToNumericMap<SyntaxKind, true>(

[

SyntaxKind.Identifier,

SyntaxKind.StringLiteral,

SyntaxKind.NumericLiteral,

SyntaxKind.BigIntLiteral,

SyntaxKind.RegularExpressionLiteral,

SyntaxKind.ThisKeyword,

SyntaxKind.PlusPlusToken,

SyntaxKind.MinusMinusToken,

SyntaxKind.CloseParenToken,

SyntaxKind.CloseBracketToken,

SyntaxKind.CloseBraceToken,

SyntaxKind.TrueKeyword,

SyntaxKind.FalseKeyword,

],

token => token,

() => true,

);

function getNewEndOfLineState(scanner: Scanner, token: SyntaxKind, lastOnTemplateStack: SyntaxKind | undefined): EndOfLineState | undefined {

switch (token) {

case SyntaxKind.StringLiteral: {

// Check to see if we finished up on a multiline string literal.

if (!scanner.isUnterminated()) return undefined;

const tokenText = scanner.getTokenText();

const lastCharIndex = tokenText.length - 1;

let numBackslashes = 0;

while (tokenText.charCodeAt(lastCharIndex - numBackslashes) === CharacterCodes.backslash) {

numBackslashes++;

}

// If we have an odd number of backslashes, then the multiline string is unclosed

if ((numBackslashes & 1) === 0) return undefined;

return tokenText.charCodeAt(0) === CharacterCodes.doubleQuote ? EndOfLineState.InDoubleQuoteStringLiteral : EndOfLineState.InSingleQuoteStringLiteral;

}

case SyntaxKind.MultiLineCommentTrivia:

// Check to see if the multiline comment was unclosed.

return scanner.isUnterminated() ? EndOfLineState.InMultiLineCommentTrivia : undefined;

default:

if (isTemplateLiteralKind(token)) {

if (!scanner.isUnterminated()) {

return undefined;

}

switch (token) {

case SyntaxKind.TemplateTail:

return EndOfLineState.InTemplateMiddleOrTail;

case SyntaxKind.NoSubstitutionTemplateLiteral:

return EndOfLineState.InTemplateHeadOrNoSubstitutionTemplate;

default:

return Debug.fail("Only 'NoSubstitutionTemplateLiteral's and 'TemplateTail's can be unterminated; got SyntaxKind #" + token);

}

}

return lastOnTemplateStack === SyntaxKind.TemplateHead ? EndOfLineState.InTemplateSubstitutionPosition : undefined;

}

}

function pushEncodedClassification(start: number, end: number, offset: number, classification: ClassificationType, result: number[]): void {

if (classification === ClassificationType.whiteSpace) {

// Don't bother with whitespace classifications. They're not needed.

return;

}

if (start === 0 && offset > 0) {

// We're classifying the first token, and this was a case where we prepended text.

// We should consider the start of this token to be at the start of the original text.

start += offset;

}

const length = end - start;

if (length > 0) {

// All our tokens are in relation to the augmented text. Move them back to be

// relative to the original text.

result.push(start - offset, length, classification);

}

}

function convertClassificationsToResult(classifications: Classifications, text: string): ClassificationResult {

const entries: ClassificationInfo[] = [];

const dense = classifications.spans;

let lastEnd = 0;

for (let i = 0; i < dense.length; i += 3) {

const start = dense[i];

const length = dense[i + 1];

const type = dense[i + 2] as ClassificationType;

// Make a whitespace entry between the last item and this one.

if (lastEnd >= 0) {

const whitespaceLength = start - lastEnd;

if (whitespaceLength > 0) {

entries.push({ length: whitespaceLength, classification: TokenClass.Whitespace });

}

}

entries.push({ length, classification: convertClassification(type) });

lastEnd = start + length;

}

const whitespaceLength = text.length - lastEnd;

if (whitespaceLength > 0) {

entries.push({ length: whitespaceLength, classification: TokenClass.Whitespace });

}

return { entries, finalLexState: classifications.endOfLineState };

}

function convertClassification(type: ClassificationType): TokenClass {

switch (type) {

case ClassificationType.comment:

return TokenClass.Comment;

case ClassificationType.keyword:

return TokenClass.Keyword;

case ClassificationType.numericLiteral:

return TokenClass.NumberLiteral;

case ClassificationType.bigintLiteral:

return TokenClass.BigIntLiteral;

case ClassificationType.operator:

return TokenClass.Operator;

case ClassificationType.stringLiteral:

return TokenClass.StringLiteral;

case ClassificationType.whiteSpace:

return TokenClass.Whitespace;

case ClassificationType.punctuation:

return TokenClass.Punctuation;

case ClassificationType.identifier:

case ClassificationType.className:

case ClassificationType.enumName:

case ClassificationType.interfaceName:

case ClassificationType.moduleName:

case ClassificationType.typeParameterName:

case ClassificationType.typeAliasName:

case ClassificationType.text:

case ClassificationType.parameterName:

return TokenClass.Identifier;

default:

return undefined!; // TODO: GH#18217 Debug.assertNever(type);

}

}

/** Returns true if 'keyword2' can legally follow 'keyword1' in any language construct. */

function canFollow(keyword1: SyntaxKind, keyword2: SyntaxKind): boolean {

if (!isAccessibilityModifier(keyword1)) {

// Assume any other keyword combination is legal.

// This can be refined in the future if there are more cases we want the classifier to be better at.

return true;

}

switch (keyword2) {

case SyntaxKind.GetKeyword:

case SyntaxKind.SetKeyword:

case SyntaxKind.ConstructorKeyword:

case SyntaxKind.StaticKeyword:

case SyntaxKind.AccessorKeyword:

return true; // Allow things like "public get", "public constructor" and "public static".

default:

return false; // Any other keyword following "public" is actually an identifier, not a real keyword.

}

}

function getPrefixFromLexState(lexState: EndOfLineState): { readonly prefix: string; readonly pushTemplate?: true; } {

// If we're in a string literal, then prepend: "\

// (and a newline). That way when we lex we'll think we're still in a string literal.

//

// If we're in a multiline comment, then prepend: /*

// (and a newline). That way when we lex we'll think we're still in a multiline comment.

switch (lexState) {

case EndOfLineState.InDoubleQuoteStringLiteral:

return { prefix: '"\\\n' };

case EndOfLineState.InSingleQuoteStringLiteral:

return { prefix: "'\\\n" };

case EndOfLineState.InMultiLineCommentTrivia:

return { prefix: "/*\n" };

case EndOfLineState.InTemplateHeadOrNoSubstitutionTemplate:

return { prefix: "`\n" };

case EndOfLineState.InTemplateMiddleOrTail:

return { prefix: "}\n", pushTemplate: true };

case EndOfLineState.InTemplateSubstitutionPosition:

return { prefix: "", pushTemplate: true };

case EndOfLineState.None:

return { prefix: "" };

default:

return Debug.assertNever(lexState);

}

}

function isBinaryExpressionOperatorToken(token: SyntaxKind): boolean {

switch (token) {

case SyntaxKind.AsteriskToken:

case SyntaxKind.SlashToken:

case SyntaxKind.PercentToken:

case SyntaxKind.PlusToken:

case SyntaxKind.MinusToken:

case SyntaxKind.LessThanLessThanToken:

case SyntaxKind.GreaterThanGreaterThanToken:

case SyntaxKind.GreaterThanGreaterThanGreaterThanToken:

case SyntaxKind.LessThanToken:

case SyntaxKind.GreaterThanToken:

case SyntaxKind.LessThanEqualsToken:

case SyntaxKind.GreaterThanEqualsToken:

case SyntaxKind.InstanceOfKeyword:

case SyntaxKind.InKeyword:

case SyntaxKind.AsKeyword:

case SyntaxKind.SatisfiesKeyword:

case SyntaxKind.EqualsEqualsToken:

case SyntaxKind.ExclamationEqualsToken:

case SyntaxKind.EqualsEqualsEqualsToken:

case SyntaxKind.ExclamationEqualsEqualsToken:

case SyntaxKind.AmpersandToken:

case SyntaxKind.CaretToken:

case SyntaxKind.BarToken:

case SyntaxKind.AmpersandAmpersandToken:

case SyntaxKind.BarBarToken:

case SyntaxKind.BarEqualsToken:

case SyntaxKind.AmpersandEqualsToken:

case SyntaxKind.CaretEqualsToken:

case SyntaxKind.LessThanLessThanEqualsToken:

case SyntaxKind.GreaterThanGreaterThanEqualsToken:

case SyntaxKind.GreaterThanGreaterThanGreaterThanEqualsToken:

case SyntaxKind.PlusEqualsToken:

case SyntaxKind.MinusEqualsToken:

case SyntaxKind.AsteriskEqualsToken:

case SyntaxKind.SlashEqualsToken:

case SyntaxKind.PercentEqualsToken:

case SyntaxKind.EqualsToken:

case SyntaxKind.CommaToken:

case SyntaxKind.QuestionQuestionToken:

case SyntaxKind.BarBarEqualsToken:

case SyntaxKind.AmpersandAmpersandEqualsToken:

case SyntaxKind.QuestionQuestionEqualsToken:

return true;

default:

return false;

}

}

function isPrefixUnaryExpressionOperatorToken(token: SyntaxKind): boolean {

switch (token) {

case SyntaxKind.PlusToken:

case SyntaxKind.MinusToken:

case SyntaxKind.TildeToken:

case SyntaxKind.ExclamationToken:

case SyntaxKind.PlusPlusToken:

case SyntaxKind.MinusMinusToken:

return true;

default:

return false;

}

}

function classFromKind(token: SyntaxKind): ClassificationType {

if (isKeyword(token)) {

return ClassificationType.keyword;

}

else if (isBinaryExpressionOperatorToken(token) || isPrefixUnaryExpressionOperatorToken(token)) {

return ClassificationType.operator;

}

else if (token >= SyntaxKind.FirstPunctuation && token <= SyntaxKind.LastPunctuation) {

return ClassificationType.punctuation;

}

switch (token) {

case SyntaxKind.NumericLiteral:

return ClassificationType.numericLiteral;

case SyntaxKind.BigIntLiteral:

return ClassificationType.bigintLiteral;

case SyntaxKind.StringLiteral:

return ClassificationType.stringLiteral;

case SyntaxKind.RegularExpressionLiteral:

return ClassificationType.regularExpressionLiteral;

case SyntaxKind.ConflictMarkerTrivia:

case SyntaxKind.MultiLineCommentTrivia:

case SyntaxKind.SingleLineCommentTrivia:

return ClassificationType.comment;

case SyntaxKind.WhitespaceTrivia:

case SyntaxKind.NewLineTrivia:

return ClassificationType.whiteSpace;

case SyntaxKind.Identifier:

default:

if (isTemplateLiteralKind(token)) {

return ClassificationType.stringLiteral;

}

return ClassificationType.identifier;

}

}

/** @internal */

export function getSemanticClassifications(typeChecker: TypeChecker, cancellationToken: CancellationToken, sourceFile: SourceFile, classifiableNames: ReadonlySet<__String>, span: TextSpan): ClassifiedSpan[] {

return convertClassificationsToSpans(getEncodedSemanticClassifications(typeChecker, cancellationToken, sourceFile, classifiableNames, span));

}

function checkForClassificationCancellation(cancellationToken: CancellationToken, kind: SyntaxKind) {

// We don't want to actually call back into our host on every node to find out if we've

// been canceled. That would be an enormous amount of chattyness, along with the all

// the overhead of marshalling the data to/from the host. So instead we pick a few

// reasonable node kinds to bother checking on. These node kinds represent high level

// constructs that we would expect to see commonly, but just at a far less frequent

// interval.

//

// For example, in checker.ts (around 750k) we only have around 600 of these constructs.

// That means we're calling back into the host around every 1.2k of the file we process.

// Lib.d.ts has similar numbers.

switch (kind) {

case SyntaxKind.ModuleDeclaration:

case SyntaxKind.ClassDeclaration:

case SyntaxKind.InterfaceDeclaration:

case SyntaxKind.FunctionDeclaration:

case SyntaxKind.ClassExpression:

case SyntaxKind.FunctionExpression:

case SyntaxKind.ArrowFunction:

cancellationToken.throwIfCancellationRequested();

}

}

/** @internal */

export function getEncodedSemanticClassifications(typeChecker: TypeChecker, cancellationToken: CancellationToken, sourceFile: SourceFile, classifiableNames: ReadonlySet<__String>, span: TextSpan): Classifications {

const spans: number[] = [];

sourceFile.forEachChild(function cb(node: Node): void {

// Only walk into nodes that intersect the requested span.

if (!node || !textSpanIntersectsWith(span, node.pos, node.getFullWidth())) {

return;

}

checkForClassificationCancellation(cancellationToken, node.kind);

// Only bother calling into the typechecker if this is an identifier that

// could possibly resolve to a type name. This makes classification run

// in a third of the time it would normally take.

if (isIdentifier(node) && !nodeIsMissing(node) && classifiableNames.has(node.escapedText)) {

const symbol = typeChecker.getSymbolAtLocation(node);

const type = symbol && classifySymbol(symbol, getMeaningFromLocation(node), typeChecker);

if (type) {

pushClassification(node.getStart(sourceFile), node.getEnd(), type);

}

}

node.forEachChild(cb);

});

return { spans, endOfLineState: EndOfLineState.None };

function pushClassification(start: number, end: number, type: ClassificationType): void {

const length = end - start;

Debug.assert(length > 0, `Classification had non-positive length of ${length}`);

spans.push(start);

spans.push(length);

spans.push(type);

}

}

function classifySymbol(symbol: Symbol, meaningAtPosition: SemanticMeaning, checker: TypeChecker): ClassificationType | undefined {

const flags = symbol.getFlags();

if ((flags & SymbolFlags.Classifiable) === SymbolFlags.None) {

return undefined;

}

else if (flags & SymbolFlags.Class) {

return ClassificationType.className;

}

else if (flags & SymbolFlags.Enum) {

return ClassificationType.enumName;

}

else if (flags & SymbolFlags.TypeAlias) {

return ClassificationType.typeAliasName;

}

else if (flags & SymbolFlags.Module) {

// Only classify a module as such if

// - It appears in a namespace context.

// - There exists a module declaration which actually impacts the value side.

return meaningAtPosition & SemanticMeaning.Namespace || meaningAtPosition & SemanticMeaning.Value && hasValueSideModule(symbol) ? ClassificationType.moduleName : undefined;

}

else if (flags & SymbolFlags.Alias) {

return classifySymbol(checker.getAliasedSymbol(symbol), meaningAtPosition, checker);

}

else if (meaningAtPosition & SemanticMeaning.Type) {

return flags & SymbolFlags.Interface ? ClassificationType.interfaceName : flags & SymbolFlags.TypeParameter ? ClassificationType.typeParameterName : undefined;

}

else {

return undefined;

}

}

/** Returns true if there exists a module that introduces entities on the value side. */

function hasValueSideModule(symbol: Symbol): boolean {

return some(symbol.declarations, declaration => isModuleDeclaration(declaration) && getModuleInstanceState(declaration) === ModuleInstanceState.Instantiated);

}

function getClassificationTypeName(type: ClassificationType): ClassificationTypeNames {

switch (type) {

case ClassificationType.comment:

return ClassificationTypeNames.comment;

case ClassificationType.identifier:

return ClassificationTypeNames.identifier;

case ClassificationType.keyword:

return ClassificationTypeNames.keyword;

case ClassificationType.numericLiteral:

return ClassificationTypeNames.numericLiteral;

case ClassificationType.bigintLiteral:

return ClassificationTypeNames.bigintLiteral;

case ClassificationType.operator:

return ClassificationTypeNames.operator;

case ClassificationType.stringLiteral:

return ClassificationTypeNames.stringLiteral;

case ClassificationType.whiteSpace:

return ClassificationTypeNames.whiteSpace;

case ClassificationType.text:

return ClassificationTypeNames.text;

case ClassificationType.punctuation:

return ClassificationTypeNames.punctuation;

case ClassificationType.className:

return ClassificationTypeNames.className;

case ClassificationType.enumName:

return ClassificationTypeNames.enumName;

case ClassificationType.interfaceName:

return ClassificationTypeNames.interfaceName;

case ClassificationType.moduleName:

return ClassificationTypeNames.moduleName;

case ClassificationType.typeParameterName:

return ClassificationTypeNames.typeParameterName;

case ClassificationType.typeAliasName:

return ClassificationTypeNames.typeAliasName;

case ClassificationType.parameterName:

return ClassificationTypeNames.parameterName;

case ClassificationType.docCommentTagName:

return ClassificationTypeNames.docCommentTagName;

case ClassificationType.jsxOpenTagName:

return ClassificationTypeNames.jsxOpenTagName;

case ClassificationType.jsxCloseTagName:

return ClassificationTypeNames.jsxCloseTagName;

case ClassificationType.jsxSelfClosingTagName:

return ClassificationTypeNames.jsxSelfClosingTagName;

case ClassificationType.jsxAttribute:

return ClassificationTypeNames.jsxAttribute;

case ClassificationType.jsxText:

return ClassificationTypeNames.jsxText;

case ClassificationType.jsxAttributeStringLiteralValue:

return ClassificationTypeNames.jsxAttributeStringLiteralValue;

default:

return undefined!; // TODO: GH#18217 Debug.assertNever(type);

}

}

function convertClassificationsToSpans(classifications: Classifications): ClassifiedSpan[] {

Debug.assert(classifications.spans.length % 3 === 0);

const dense = classifications.spans;

const result: ClassifiedSpan[] = [];

for (let i = 0; i < dense.length; i += 3) {

result.push({

textSpan: createTextSpan(dense[i], dense[i + 1]),

classificationType: getClassificationTypeName(dense[i + 2]),

});

}

return result;

}

/** @internal */

export function getSyntacticClassifications(cancellationToken: CancellationToken, sourceFile: SourceFile, span: TextSpan): ClassifiedSpan[] {

return convertClassificationsToSpans(getEncodedSyntacticClassifications(cancellationToken, sourceFile, span));

}

/** @internal */

export function getEncodedSyntacticClassifications(cancellationToken: CancellationToken, sourceFile: SourceFile, span: TextSpan): Classifications {

const spanStart = span.start;

const spanLength = span.length;

// Make a scanner we can get trivia from.

const triviaScanner = createScanner(ScriptTarget.Latest, /*skipTrivia*/ false, sourceFile.languageVariant, sourceFile.text);

const mergeConflictScanner = createScanner(ScriptTarget.Latest, /*skipTrivia*/ false, sourceFile.languageVariant, sourceFile.text);

const result: number[] = [];

processElement(sourceFile);

return { spans: result, endOfLineState: EndOfLineState.None };

function pushClassification(start: number, length: number, type: ClassificationType) {

result.push(start);

result.push(length);

result.push(type);

}

function classifyLeadingTriviaAndGetTokenStart(token: Node): number {

triviaScanner.resetTokenState(token.pos);

while (true) {

const start = triviaScanner.getTokenEnd();

// only bother scanning if we have something that could be trivia.

if (!couldStartTrivia(sourceFile.text, start)) {

return start;

}

const kind = triviaScanner.scan();

const end = triviaScanner.getTokenEnd();

const width = end - start;

// The moment we get something that isn't trivia, then stop processing.

if (!isTrivia(kind)) {

return start;

}

switch (kind) {

case SyntaxKind.NewLineTrivia:

case SyntaxKind.WhitespaceTrivia:

// Don't bother with newlines/whitespace.

continue;

case SyntaxKind.SingleLineCommentTrivia:

case SyntaxKind.MultiLineCommentTrivia:

// Only bother with the trivia if it at least intersects the span of interest.

classifyComment(token, kind, start, width);

// Classifying a comment might cause us to reuse the trivia scanner

// (because of jsdoc comments). So after we classify the comment make

// sure we set the scanner position back to where it needs to be.

triviaScanner.resetTokenState(end);

continue;

case SyntaxKind.ConflictMarkerTrivia:

const text = sourceFile.text;

const ch = text.charCodeAt(start);

// for the <<<<<<< and >>>>>>> markers, we just add them in as comments

// in the classification stream.

if (ch === CharacterCodes.lessThan || ch === CharacterCodes.greaterThan) {

pushClassification(start, width, ClassificationType.comment);

continue;

}

// for the ||||||| and ======== markers, add a comment for the first line,

// and then lex all subsequent lines up until the end of the conflict marker.

Debug.assert(ch === CharacterCodes.bar || ch === CharacterCodes.equals);

classifyDisabledMergeCode(text, start, end);

break;

case SyntaxKind.ShebangTrivia:

// TODO: Maybe we should classify these.

break;

default:

Debug.assertNever(kind);

}

}

}

function classifyComment(token: Node, kind: SyntaxKind, start: number, width: number) {

if (kind === SyntaxKind.MultiLineCommentTrivia) {

// See if this is a doc comment. If so, we'll classify certain portions of it

// specially.

const docCommentAndDiagnostics = parseIsolatedJSDocComment(sourceFile.text, start, width);

if (docCommentAndDiagnostics && docCommentAndDiagnostics.jsDoc) {

// TODO: This should be predicated on `token["kind"]` being compatible with `HasJSDoc["kind"]`

setParent(docCommentAndDiagnostics.jsDoc, token as HasJSDoc);

classifyJSDocComment(docCommentAndDiagnostics.jsDoc);

return;

}

}

else if (kind === SyntaxKind.SingleLineCommentTrivia) {

if (tryClassifyTripleSlashComment(start, width)) {

return;

}

}

// Simple comment. Just add as is.

pushCommentRange(start, width);

}

function pushCommentRange(start: number, width: number) {

pushClassification(start, width, ClassificationType.comment);

}

function classifyJSDocComment(docComment: JSDoc) {

let pos = docComment.pos;

if (docComment.tags) {

for (const tag of docComment.tags) {

// As we walk through each tag, classify the portion of text from the end of

// the last tag (or the start of the entire doc comment) as 'comment'.

if (tag.pos !== pos) {

pushCommentRange(pos, tag.pos - pos);

}

pushClassification(tag.pos, 1, ClassificationType.punctuation); // "@"

pushClassification(tag.tagName.pos, tag.tagName.end - tag.tagName.pos, ClassificationType.docCommentTagName); // e.g. "param"

pos = tag.tagName.end;

let commentStart = tag.tagName.end;

switch (tag.kind) {

case SyntaxKind.JSDocParameterTag:

const param = tag as JSDocParameterTag;

processJSDocParameterTag(param);

commentStart = param.isNameFirst && param.typeExpression?.end || param.name.end;

break;

case SyntaxKind.JSDocPropertyTag:

const prop = tag as JSDocPropertyTag;

commentStart = prop.isNameFirst && prop.typeExpression?.end || prop.name.end;

break;

case SyntaxKind.JSDocTemplateTag:

processJSDocTemplateTag(tag as JSDocTemplateTag);

pos = tag.end;

commentStart = (tag as JSDocTemplateTag).typeParameters.end;

break;

case SyntaxKind.JSDocTypedefTag:

const type = tag as JSDocTypedefTag;

commentStart = type.typeExpression?.kind === SyntaxKind.JSDocTypeExpression && type.fullName?.end || type.typeExpression?.end || commentStart;

break;

case SyntaxKind.JSDocCallbackTag:

commentStart = (tag as JSDocCallbackTag).typeExpression.end;

break;

case SyntaxKind.JSDocTypeTag:

processElement((tag as JSDocTypeTag).typeExpression);

pos = tag.end;

commentStart = (tag as JSDocTypeTag).typeExpression.end;

break;

case SyntaxKind.JSDocThisTag:

case SyntaxKind.JSDocEnumTag:

commentStart = (tag as JSDocThisTag | JSDocEnumTag).typeExpression.end;

break;

case SyntaxKind.JSDocReturnTag:

processElement((tag as JSDocReturnTag).typeExpression);

pos = tag.end;

commentStart = (tag as JSDocReturnTag).typeExpression?.end || commentStart;

break;

case SyntaxKind.JSDocSeeTag:

commentStart = (tag as JSDocSeeTag).name?.end || commentStart;

break;

case SyntaxKind.JSDocAugmentsTag:

case SyntaxKind.JSDocImplementsTag:

commentStart = (tag as JSDocImplementsTag | JSDocAugmentsTag).class.end;

break;

case SyntaxKind.JSDocThrowsTag:

processElement((tag as JSDocThrowsTag).typeExpression);

pos = tag.end;

commentStart = (tag as JSDocThrowsTag).typeExpression?.end || commentStart;

break;

}

if (typeof tag.comment === "object") {

pushCommentRange(tag.comment.pos, tag.comment.end - tag.comment.pos);

}

else if (typeof tag.comment === "string") {

pushCommentRange(commentStart, tag.end - commentStart);

}

}

}

if (pos !== docComment.end) {

pushCommentRange(pos, docComment.end - pos);

}

return;

function processJSDocParameterTag(tag: JSDocParameterTag) {

if (tag.isNameFirst) {

pushCommentRange(pos, tag.name.pos - pos);

pushClassification(tag.name.pos, tag.name.end - tag.name.pos, ClassificationType.parameterName);

pos = tag.name.end;

}

if (tag.typeExpression) {

pushCommentRange(pos, tag.typeExpression.pos - pos);

processElement(tag.typeExpression);

pos = tag.typeExpression.end;

}

if (!tag.isNameFirst) {

pushCommentRange(pos, tag.name.pos - pos);

pushClassification(tag.name.pos, tag.name.end - tag.name.pos, ClassificationType.parameterName);

pos = tag.name.end;

}

}

}

function tryClassifyTripleSlashComment(start: number, width: number): boolean {

const tripleSlashXMLCommentRegEx = /^(\/\/\/\s*)(<)(?:(\S+)((?:[^/]|\/[^>])*)(\/>)?)?/im;

// Require a leading whitespace character (the parser already does) to prevent terrible backtracking performance

const attributeRegex = /(\s)(\S+)(\s*)(=)(\s*)('[^']+'|"[^"]+")/img;

const text = sourceFile.text.substr(start, width);

const match = tripleSlashXMLCommentRegEx.exec(text);

if (!match) {

return false;

}

// Limiting classification to exactly the elements and attributes

// defined in `ts.commentPragmas` would be excessive, but we can avoid

// some obvious false positives (e.g. in XML-like doc comments) by

// checking the element name.

// eslint-disable-next-line local/no-in-operator

if (!match[3] || !(match[3] in commentPragmas)) {

return false;

}

let pos = start;

pushCommentRange(pos, match[1].length); // ///

pos += match[1].length;

pushClassification(pos, match[2].length, ClassificationType.punctuation); // <

pos += match[2].length;

pushClassification(pos, match[3].length, ClassificationType.jsxSelfClosingTagName); // element name

pos += match[3].length;

const attrText = match[4];

let attrPos = pos;

while (true) {

const attrMatch = attributeRegex.exec(attrText);

if (!attrMatch) {

break;

}

const newAttrPos = pos + attrMatch.index + attrMatch[1].length; // whitespace

if (newAttrPos > attrPos) {

pushCommentRange(attrPos, newAttrPos - attrPos);

attrPos = newAttrPos;

}

pushClassification(attrPos, attrMatch[2].length, ClassificationType.jsxAttribute); // attribute name

attrPos += attrMatch[2].length;

if (attrMatch[3].length) {

pushCommentRange(attrPos, attrMatch[3].length); // whitespace

attrPos += attrMatch[3].length;

}

pushClassification(attrPos, attrMatch[4].length, ClassificationType.operator); // =

attrPos += attrMatch[4].length;

if (attrMatch[5].length) {

pushCommentRange(attrPos, attrMatch[5].length); // whitespace

attrPos += attrMatch[5].length;

}

pushClassification(attrPos, attrMatch[6].length, ClassificationType.jsxAttributeStringLiteralValue); // attribute value

attrPos += attrMatch[6].length;

}

pos += match[4].length;

if (pos > attrPos) {

pushCommentRange(attrPos, pos - attrPos);

}

if (match[5]) {