bitmark-grammar/src/typescript-es6/antlr4ts/Token.ts

A bitmark parser

/*!
 * Copyright 2016 The ANTLR Project. All rights reserved.
 * Licensed under the BSD-3-Clause license. See LICENSE file in the project root for license information.
 */

// ConvertTo-TS run at 2016-10-04T11:26:57.7862802-07:00

import { CharStream } from "./CharStream";
import { IntStream } from "./IntStream";
import { TokenSource } from "./TokenSource";
import { TokenStream } from "./TokenStream";

/** A token has properties: text, type, line, character position in the line
 *  (so we can ignore tabs), token channel, index, and source from which
 *  we obtained this token.
 */
export interface Token {
	/**
	 * Get the text of the token.
	 */
	readonly text: string | undefined;

	/** Get the token type of the token */
	readonly type: number;

	/** The line number on which the 1st character of this token was matched,
	 *  line=1..n
	 */
	readonly line: number;

	/** The index of the first character of this token relative to the
	 *  beginning of the line at which it occurs, 0..n-1
	 */
	readonly charPositionInLine: number;

	/** Return the channel this token. Each token can arrive at the parser
	 *  on a different channel, but the parser only "tunes" to a single channel.
	 *  The parser ignores everything not on DEFAULT_CHANNEL.
	 */
	readonly channel: number;

	/** An index from 0..n-1 of the token object in the input stream.
	 *  This must be valid in order to print token streams and
	 *  use TokenRewriteStream.
	 *
	 *  Return -1 to indicate that this token was conjured up since
	 *  it doesn't have a valid index.
	 */
	readonly tokenIndex: number;

	/** The starting character index of the token
	 *  This method is optional; return -1 if not implemented.
	 */
	readonly startIndex: number;

	/** The last character index of the token.
	 *  This method is optional; return -1 if not implemented.
	 */
	readonly stopIndex: number;

	/** Gets the {@link TokenSource} which created this token.
	 */
	readonly tokenSource: TokenSource | undefined;

	/**
	 * Gets the {@link CharStream} from which this token was derived.
	 */
	readonly inputStream: CharStream | undefined;
}

export namespace Token {
	export const INVALID_TYPE: number = 0;

	/** During lookahead operations, this "token" signifies we hit rule end ATN state
	 *  and did not follow it despite needing to.
	 */
	export const EPSILON: number = -2;

	export const MIN_USER_TOKEN_TYPE: number = 1;

	export const EOF: number = IntStream.EOF;

	/** All tokens go to the parser (unless skip() is called in that rule)
	 *  on a particular "channel".  The parser tunes to a particular channel
	 *  so that whitespace etc... can go to the parser on a "hidden" channel.
	 */
	export const DEFAULT_CHANNEL: number = 0;

	/** Anything on different channel than DEFAULT_CHANNEL is not parsed
	 *  by parser.
	 */
	export const HIDDEN_CHANNEL: number = 1;

	/**
	 * This is the minimum constant value which can be assigned to a
	 * user-defined token channel.
	 *
	 * The non-negative numbers less than {@link #MIN_USER_CHANNEL_VALUE} are
	 * assigned to the predefined channels {@link #DEFAULT_CHANNEL} and
	 * {@link #HIDDEN_CHANNEL}.
	 *
	 * @see `Token.channel`
	 */
	export const MIN_USER_CHANNEL_VALUE: number = 2;
}