Question: `SyntaxKind` number to a string

[basarat]

Having SyntaxKind as a const enum means there isn't a lookup I can use.

I need this for TypeStrong/atom-typescript#233

Is there something like this already there or do I need to do this manually. Cheers 🌹

[basarat]

In the absence of a better suggestion I've gone with:

/** Copy paste from typescript.d.ts */
enum SyntaxKind {
    Unknown,
    EndOfFileToken,
    SingleLineCommentTrivia,
    MultiLineCommentTrivia,
    NewLineTrivia,
    WhitespaceTrivia,
    // We detect and provide better error recovery when we encounter a git merge marker.  This
    // allows us to edit files with git-conflict markers in them in a much more pleasant manner.
    ConflictMarkerTrivia,
    // Literals
    NumericLiteral,
    StringLiteral,
    RegularExpressionLiteral,
    NoSubstitutionTemplateLiteral,
    // Pseudo-literals
    TemplateHead,
    TemplateMiddle,
    TemplateTail,
    // Punctuation
    OpenBraceToken,
    CloseBraceToken,
    OpenParenToken,
    CloseParenToken,
    OpenBracketToken,
    CloseBracketToken,
    DotToken,
    DotDotDotToken,
    SemicolonToken,
    CommaToken,
    LessThanToken,
    GreaterThanToken,
    LessThanEqualsToken,
    GreaterThanEqualsToken,
    EqualsEqualsToken,
    ExclamationEqualsToken,
    EqualsEqualsEqualsToken,
    ExclamationEqualsEqualsToken,
    EqualsGreaterThanToken,
    PlusToken,
    MinusToken,
    AsteriskToken,
    SlashToken,
    PercentToken,
    PlusPlusToken,
    MinusMinusToken,
    LessThanLessThanToken,
    GreaterThanGreaterThanToken,
    GreaterThanGreaterThanGreaterThanToken,
    AmpersandToken,
    BarToken,
    CaretToken,
    ExclamationToken,
    TildeToken,
    AmpersandAmpersandToken,
    BarBarToken,
    QuestionToken,
    ColonToken,
    AtToken,
    // Assignments
    EqualsToken,
    PlusEqualsToken,
    MinusEqualsToken,
    AsteriskEqualsToken,
    SlashEqualsToken,
    PercentEqualsToken,
    LessThanLessThanEqualsToken,
    GreaterThanGreaterThanEqualsToken,
    GreaterThanGreaterThanGreaterThanEqualsToken,
    AmpersandEqualsToken,
    BarEqualsToken,
    CaretEqualsToken,
    // Identifiers
    Identifier,
    // Reserved words
    BreakKeyword,
    CaseKeyword,
    CatchKeyword,
    ClassKeyword,
    ConstKeyword,
    ContinueKeyword,
    DebuggerKeyword,
    DefaultKeyword,
    DeleteKeyword,
    DoKeyword,
    ElseKeyword,
    EnumKeyword,
    ExportKeyword,
    ExtendsKeyword,
    FalseKeyword,
    FinallyKeyword,
    ForKeyword,
    FunctionKeyword,
    IfKeyword,
    ImportKeyword,
    InKeyword,
    InstanceOfKeyword,
    NewKeyword,
    NullKeyword,
    ReturnKeyword,
    SuperKeyword,
    SwitchKeyword,
    ThisKeyword,
    ThrowKeyword,
    TrueKeyword,
    TryKeyword,
    TypeOfKeyword,
    VarKeyword,
    VoidKeyword,
    WhileKeyword,
    WithKeyword,
    // Strict mode reserved words
    AsKeyword,
    ImplementsKeyword,
    InterfaceKeyword,
    LetKeyword,
    PackageKeyword,
    PrivateKeyword,
    ProtectedKeyword,
    PublicKeyword,
    StaticKeyword,
    YieldKeyword,
    // Contextual keywords
    AnyKeyword,
    BooleanKeyword,
    ConstructorKeyword,
    DeclareKeyword,
    GetKeyword,
    ModuleKeyword,
    RequireKeyword,
    NumberKeyword,
    SetKeyword,
    StringKeyword,
    SymbolKeyword,
    TypeKeyword,
    FromKeyword,
    OfKeyword, // LastKeyword and LastToken

    // Parse tree nodes

    // Names
    QualifiedName,
    ComputedPropertyName,
    // Signature elements
    TypeParameter,
    Parameter,
    Decorator,
    // TypeMember
    PropertySignature,
    PropertyDeclaration,
    MethodSignature,
    MethodDeclaration,
    Constructor,
    GetAccessor,
    SetAccessor,
    CallSignature,
    ConstructSignature,
    IndexSignature,
    // Type
    TypeReference,
    FunctionType,
    ConstructorType,
    TypeQuery,
    TypeLiteral,
    ArrayType,
    TupleType,
    UnionType,
    ParenthesizedType,
    // Binding patterns
    ObjectBindingPattern,
    ArrayBindingPattern,
    BindingElement,
    // Expression
    ArrayLiteralExpression,
    ObjectLiteralExpression,
    PropertyAccessExpression,
    ElementAccessExpression,
    CallExpression,
    NewExpression,
    TaggedTemplateExpression,
    TypeAssertionExpression,
    ParenthesizedExpression,
    FunctionExpression,
    ArrowFunction,
    DeleteExpression,
    TypeOfExpression,
    VoidExpression,
    PrefixUnaryExpression,
    PostfixUnaryExpression,
    BinaryExpression,
    ConditionalExpression,
    TemplateExpression,
    YieldExpression,
    SpreadElementExpression,
    ClassExpression,
    OmittedExpression,
    // Misc
    TemplateSpan,
    HeritageClauseElement,
    SemicolonClassElement,
    // Element
    Block,
    VariableStatement,
    EmptyStatement,
    ExpressionStatement,
    IfStatement,
    DoStatement,
    WhileStatement,
    ForStatement,
    ForInStatement,
    ForOfStatement,
    ContinueStatement,
    BreakStatement,
    ReturnStatement,
    WithStatement,
    SwitchStatement,
    LabeledStatement,
    ThrowStatement,
    TryStatement,
    DebuggerStatement,
    VariableDeclaration,
    VariableDeclarationList,
    FunctionDeclaration,
    ClassDeclaration,
    InterfaceDeclaration,
    TypeAliasDeclaration,
    EnumDeclaration,
    ModuleDeclaration,
    ModuleBlock,
    CaseBlock,
    ImportEqualsDeclaration,
    ImportDeclaration,
    ImportClause,
    NamespaceImport,
    NamedImports,
    ImportSpecifier,
    ExportAssignment,
    ExportDeclaration,
    NamedExports,
    ExportSpecifier,
    MissingDeclaration,

    // Module references
    ExternalModuleReference,

    // Clauses
    CaseClause,
    DefaultClause,
    HeritageClause,
    CatchClause,

    // Property assignments
    PropertyAssignment,
    ShorthandPropertyAssignment,

    // Enum
    EnumMember,
    // Top-level nodes
    SourceFile,

    // Synthesized list
    SyntaxList,
    // Enum value count
    Count,
    // Markers
    FirstAssignment = EqualsToken,
    LastAssignment = CaretEqualsToken,
    FirstReservedWord = BreakKeyword,
    LastReservedWord = WithKeyword,
    FirstKeyword = BreakKeyword,
    LastKeyword = OfKeyword,
    FirstFutureReservedWord = ImplementsKeyword,
    LastFutureReservedWord = YieldKeyword,
    FirstTypeNode = TypeReference,
    LastTypeNode = ParenthesizedType,
    FirstPunctuation = OpenBraceToken,
    LastPunctuation = CaretEqualsToken,
    FirstToken = Unknown,
    LastToken = LastKeyword,
    FirstTriviaToken = SingleLineCommentTrivia,
    LastTriviaToken = ConflictMarkerTrivia,
    FirstLiteralToken = NumericLiteral,
    LastLiteralToken = NoSubstitutionTemplateLiteral,
    FirstTemplateToken = NoSubstitutionTemplateLiteral,
    LastTemplateToken = TemplateTail,
    FirstBinaryOperator = LessThanToken,
    LastBinaryOperator = CaretEqualsToken,
    FirstNode = QualifiedName,
}

import * as ts from "typescript";
export default function syntaxKindToString(syntaxKind: ts.SyntaxKind): string {
    return SyntaxKind[syntaxKind];
}

Let me know if I'm being irrational ❤️

[DanielRosenwasser]

I'd just make a function that uses the preserved const enum value by casting ts to any

[mhegazy]

We are always building typescriptServices.js with --preserveConstEnums. so the enum exists at run time. it is just the compiler does not let you use it. So as @DanielRosenwasser mentioned:

(<any>ts).SyntaxKind[kind]

The main issue here is we want to have our cake and eat it too :D. We would like to get the perf optimization and size reduction of const enums for the compiler, but we also acknowledge that users of the services file/node package would want to refer to enums by their name instead of values from plain .js files. --perserveConstEnum trick seems to work, though un-elegant.

[basarat]

Works perfectly. I'll keep this in mind ❤️

[lmcarreiro]

@basarat How did you handle to avoid get the markers name instead of the real kind name? I open the issue #20129, but I don't know if there is already a solution for this...

Update: I ended up creating a function to map these markers names to the real kind names: https://gist.github.com/lmcarreiro/3a2af88320025879317dce951bad0258, but as I said (#20129 (comment)) it can break with future versions.