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# Token Types
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Enumeration of lexical token types for parsing and syntax highlighting in the TypeScript-ESTree ecosystem. These constants enable type-safe token classification and processing.
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## Capabilities
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### AST_TOKEN_TYPES Enum
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Complete enumeration of all token types recognized by the TypeScript parser.
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```typescript { .api }
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enum AST_TOKEN_TYPES {
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  // Literal tokens
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  Boolean = 'Boolean',
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  Null = 'Null',
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  Numeric = 'Numeric',
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  String = 'String',
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  RegularExpression = 'RegularExpression',
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  Template = 'Template',
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  // Identifier tokens
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  Identifier = 'Identifier',
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  JSXIdentifier = 'JSXIdentifier',
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  PrivateIdentifier = 'PrivateIdentifier',
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  // Special tokens
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  JSXText = 'JSXText',
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  Keyword = 'Keyword',
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  Punctuator = 'Punctuator',
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  // Comment tokens
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  Block = 'Block',
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  Line = 'Line',
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}
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```
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**Usage Examples:**
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```typescript
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import { AST_TOKEN_TYPES } from "@typescript-eslint/types";
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// Token classification
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function classifyToken(token: Token): string {
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  switch (token.type) {
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    case AST_TOKEN_TYPES.Identifier:
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      return `Identifier: ${token.value}`;
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    case AST_TOKEN_TYPES.Keyword:
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      return `Keyword: ${token.value}`;
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    case AST_TOKEN_TYPES.String:
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      return `String literal: ${token.value}`;
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    case AST_TOKEN_TYPES.Numeric:
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      return `Number: ${token.value}`;
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    case AST_TOKEN_TYPES.Boolean:
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      return `Boolean: ${token.value}`;
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    case AST_TOKEN_TYPES.Block:
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    case AST_TOKEN_TYPES.Line:
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      return `Comment: ${token.value}`;
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    default:
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      return `Other token: ${token.type}`;
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  }
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}
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// Filter tokens by category
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function isLiteralToken(tokenType: AST_TOKEN_TYPES): boolean {
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  return [
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    AST_TOKEN_TYPES.Boolean,
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    AST_TOKEN_TYPES.Null,
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    AST_TOKEN_TYPES.Numeric,
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    AST_TOKEN_TYPES.String,
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    AST_TOKEN_TYPES.RegularExpression,
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    AST_TOKEN_TYPES.Template,
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  ].includes(tokenType);
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}
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function isCommentToken(tokenType: AST_TOKEN_TYPES): boolean {
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  return tokenType === AST_TOKEN_TYPES.Block || tokenType === AST_TOKEN_TYPES.Line;
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}
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```
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## Token Categories
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### Literal Tokens
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Tokens representing literal values in the source code:
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- **Boolean**: `true`, `false`
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- **Null**: `null`
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- **Numeric**: Integer and floating-point numbers (`42`, `3.14`, `0x1F`)
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- **String**: String literals (`"hello"`, `'world'`, `` `template` ``)
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- **RegularExpression**: Regular expression literals (`/pattern/flags`)
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- **Template**: Template literal parts (`` `hello ${name}` ``)
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### Identifier Tokens
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Tokens representing names and identifiers:
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- **Identifier**: Standard JavaScript identifiers (`variable`, `functionName`)
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- **JSXIdentifier**: JSX element and attribute names (`<div>`, `className`)
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- **PrivateIdentifier**: Private class field names (`#privateField`)
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### Special Tokens
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- **JSXText**: Text content within JSX elements
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- **Keyword**: Reserved JavaScript/TypeScript keywords (`function`, `class`, `interface`)
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- **Punctuator**: Operators and punctuation (`;`, `{`, `}`, `+`, `=>`)
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### Comment Tokens
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Tokens representing comments in the source code:
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- **Block**: Multi-line comments (`/* comment */`)
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- **Line**: Single-line comments (`// comment`)
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**Usage in Syntax Highlighting:**
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```typescript
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import { AST_TOKEN_TYPES } from "@typescript-eslint/types";
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function getTokenStyle(tokenType: AST_TOKEN_TYPES): string {
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  switch (tokenType) {
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    case AST_TOKEN_TYPES.Keyword:
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      return 'keyword';
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    case AST_TOKEN_TYPES.String:
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    case AST_TOKEN_TYPES.Template:
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      return 'string';
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    case AST_TOKEN_TYPES.Numeric:
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    case AST_TOKEN_TYPES.Boolean:
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    case AST_TOKEN_TYPES.Null:
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      return 'literal';
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    case AST_TOKEN_TYPES.Block:
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    case AST_TOKEN_TYPES.Line:
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      return 'comment';
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    case AST_TOKEN_TYPES.Identifier:
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      return 'identifier';
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    case AST_TOKEN_TYPES.RegularExpression:
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      return 'regex';
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    default:
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      return 'default';
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  }
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}
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```