61 lines
1.3 KiB
TypeScript
61 lines
1.3 KiB
TypeScript
import { syntaxError } from '../error';
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import { Token } from './ast';
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import { Source } from './source';
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/**
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* Given a Source object, this returns a Lexer for that source.
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* A Lexer is a stateful stream generator in that every time
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* it is advanced, it returns the next token in the Source. Assuming the
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* source lexes, the final Token emitted by the lexer will be of kind
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* EOF, after which the lexer will repeatedly return the same EOF token
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* whenever called.
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*/
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export function createLexer<TOptions>(
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source: Source,
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options: TOptions,
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): Lexer<TOptions>;
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/**
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* The return type of createLexer.
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*/
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export interface Lexer<TOptions> {
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source: Source;
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options: TOptions;
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/**
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* The previously focused non-ignored token.
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*/
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lastToken: Token;
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/**
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* The currently focused non-ignored token.
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*/
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token: Token;
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/**
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* The (1-indexed) line containing the current token.
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*/
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line: number;
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/**
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* The character offset at which the current line begins.
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*/
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lineStart: number;
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/**
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* Advances the token stream to the next non-ignored token.
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*/
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advance(): Token;
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/**
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* Looks ahead and returns the next non-ignored token, but does not change
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* the Lexer's state.
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*/
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lookahead(): Token;
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}
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/**
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* @internal
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*/
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export function isPunctuatorToken(token: Token): boolean;
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