81 lines
3.0 KiB
TypeScript
81 lines
3.0 KiB
TypeScript
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import { Token, TokenKind } from './Token';
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import { TokenSequence } from './TokenSequence';
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import { ParserContext } from './ParserContext';
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/**
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* Manages a stream of tokens that are read by the parser.
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*
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* @remarks
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* Use TokenReader.readToken() to read a token and advance the stream pointer.
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* Use TokenReader.peekToken() to preview the next token.
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* Use TokenReader.createMarker() and backtrackToMarker() to rewind to an earlier point.
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* Whenever readToken() is called, the token is added to an accumulated TokenSequence
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* that can be extracted by calling extractAccumulatedSequence().
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*/
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export declare class TokenReader {
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readonly tokens: ReadonlyArray<Token>;
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private readonly _parserContext;
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private _readerStartIndex;
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private _readerEndIndex;
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private _currentIndex;
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private _accumulatedStartIndex;
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constructor(parserContext: ParserContext, embeddedTokenSequence?: TokenSequence);
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/**
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* Extracts and returns the TokenSequence that was accumulated so far by calls to readToken().
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* The next call to readToken() will start a new accumulated sequence.
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*/
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extractAccumulatedSequence(): TokenSequence;
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/**
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* Returns true if the accumulated sequence has any tokens yet. This will be false
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* when the TokenReader starts, and it will be false immediately after a call
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* to extractAccumulatedSequence(). Otherwise, it will become true whenever readToken()
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* is called.
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*/
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isAccumulatedSequenceEmpty(): boolean;
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/**
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* Like extractAccumulatedSequence(), but returns undefined if nothing has been
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* accumulated yet.
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*/
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tryExtractAccumulatedSequence(): TokenSequence | undefined;
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/**
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* Asserts that isAccumulatedSequenceEmpty() should return false. If not, an exception
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* is throw indicating a parser bug.
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*/
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assertAccumulatedSequenceIsEmpty(): void;
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/**
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* Returns the next token that would be returned by _readToken(), without
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* consuming anything.
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*/
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peekToken(): Token;
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/**
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* Returns the TokenKind for the next token that would be returned by _readToken(), without
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* consuming anything.
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*/
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peekTokenKind(): TokenKind;
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/**
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* Like peekTokenKind(), but looks ahead two tokens.
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*/
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peekTokenAfterKind(): TokenKind;
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/**
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* Like peekTokenKind(), but looks ahead three tokens.
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*/
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peekTokenAfterAfterKind(): TokenKind;
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/**
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* Extract the next token from the input stream and return it.
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* The token will also be appended to the accumulated sequence, which can
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* later be accessed via extractAccumulatedSequence().
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*/
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readToken(): Token;
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/**
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* Returns the kind of the token immediately before the current token.
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*/
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peekPreviousTokenKind(): TokenKind;
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/**
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* Remembers the current position in the stream.
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*/
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createMarker(): number;
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/**
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* Rewinds the stream pointer to a previous position in the stream.
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*/
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backtrackToMarker(marker: number): void;
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}
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//# sourceMappingURL=TokenReader.d.ts.map
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