/*!
 * 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.
 */
export declare namespace IntStream {
    /**
     * The value returned by {@link #LA LA()} when the end of the stream is
     * reached.
     */
    const EOF: number;
    /**
     * The value returned by {@link #getSourceName} when the actual name of the
     * underlying source is not known.
     */
    const UNKNOWN_SOURCE_NAME: string;
}
/**
 * A simple stream of symbols whose values are represented as integers. This
 * interface provides <em>marked ranges</em> with support for a minimum level
 * of buffering necessary to implement arbitrary lookahead during prediction.
 * For more information on marked ranges, see {@link #mark}.
 *
 * <p><strong>Initializing Methods:</strong> Some methods in this interface have
 * unspecified behavior if no call to an initializing method has occurred after
 * the stream was constructed. The following is a list of initializing methods:</p>
 *
 * <ul>
 *   <li>{@link #LA}</li>
 *   <li>{@link #consume}</li>
 *   <li>{@link #size}</li>
 * </ul>
 */
export interface IntStream {
    /**
     * Consumes the current symbol in the stream. This method has the following
     * effects:
     *
     * <ul>
     *   <li><strong>Forward movement:</strong> The value of `index`
     *		before calling this method is less than the value of `index`
     *		after calling this method.</li>
     *   <li><strong>Ordered lookahead:</strong> The value of {@code LA(1)} before
     *		calling this method becomes the value of {@code LA(-1)} after calling
     *		this method.</li>
     * </ul>
     *
     * Note that calling this method does not guarantee that `index` is
     * incremented by exactly 1, as that would preclude the ability to implement
     * filtering streams (e.g. {@link CommonTokenStream} which distinguishes
     * between "on-channel" and "off-channel" tokens).
     *
     * @throws IllegalStateException if an attempt is made to consume the the
     * end of the stream (i.e. if {@code LA(1)==}{@link #EOF EOF} before calling
     * {@code consume}).
     */
    consume(): void;
    /**
     * Gets the value of the symbol at offset {@code i} from the current
     * position. When {@code i==1}, this method returns the value of the current
     * symbol in the stream (which is the next symbol to be consumed). When
     * {@code i==-1}, this method returns the value of the previously read
     * symbol in the stream. It is not valid to call this method with
     * {@code i==0}, but the specific behavior is unspecified because this
     * method is frequently called from performance-critical code.
     *
     * <p>This method is guaranteed to succeed if any of the following are true:</p>
     *
     * <ul>
     *   <li>{@code i>0}</li>
     *   <li>{@code i==-1} and `index` returns a value greater
     *     than the value of `index` after the stream was constructed
     *     and {@code LA(1)} was called in that order. Specifying the current
     *     `index` relative to the index after the stream was created
     *     allows for filtering implementations that do not return every symbol
     *     from the underlying source. Specifying the call to {@code LA(1)}
     *     allows for lazily initialized streams.</li>
     *   <li>{@code LA(i)} refers to a symbol consumed within a marked region
     *     that has not yet been released.</li>
     * </ul>
     *
     * <p>If {@code i} represents a position at or beyond the end of the stream,
     * this method returns {@link #EOF}.</p>
     *
     * <p>The return value is unspecified if {@code i<0} and fewer than {@code -i}
     * calls to {@link #consume consume()} have occurred from the beginning of
     * the stream before calling this method.</p>
     *
     * @throws UnsupportedOperationException if the stream does not support
     * retrieving the value of the specified symbol
     */
    LA(i: number): number;
    /**
     * A mark provides a guarantee that {@link #seek seek()} operations will be
     * valid over a "marked range" extending from the index where {@code mark()}
     * was called to the current `index`. This allows the use of
     * streaming input sources by specifying the minimum buffering requirements
     * to support arbitrary lookahead during prediction.
     *
     * <p>The returned mark is an opaque handle (type {@code int}) which is passed
     * to {@link #release release()} when the guarantees provided by the marked
     * range are no longer necessary. When calls to
     * {@code mark()}/{@code release()} are nested, the marks must be released
     * in reverse order of which they were obtained. Since marked regions are
     * used during performance-critical sections of prediction, the specific
     * behavior of invalid usage is unspecified (i.e. a mark is not released, or
     * a mark is released twice, or marks are not released in reverse order from
     * which they were created).</p>
     *
     * <p>The behavior of this method is unspecified if no call to an
     * {@link IntStream initializing method} has occurred after this stream was
     * constructed.</p>
     *
     * <p>This method does not change the current position in the input stream.</p>
     *
     * <p>The following example shows the use of {@link #mark mark()},
     * {@link #release release(mark)}, `index`, and
     * {@link #seek seek(index)} as part of an operation to safely work within a
     * marked region, then restore the stream position to its original value and
     * release the mark.</p>
     * <pre>
     * IntStream stream = ...;
     * int index = -1;
     * int mark = stream.mark();
     * try {
     *   index = stream.index;
     *   // perform work here...
     * } finally {
     *   if (index != -1) {
     *     stream.seek(index);
     *   }
     *   stream.release(mark);
     * }
     * </pre>
     *
     * @return An opaque marker which should be passed to
     * {@link #release release()} when the marked range is no longer required.
     */
    mark(): number;
    /**
     * This method releases a marked range created by a call to
     * {@link #mark mark()}. Calls to {@code release()} must appear in the
     * reverse order of the corresponding calls to {@code mark()}. If a mark is
     * released twice, or if marks are not released in reverse order of the
     * corresponding calls to {@code mark()}, the behavior is unspecified.
     *
     * <p>For more information and an example, see {@link #mark}.</p>
     *
     * @param marker A marker returned by a call to {@code mark()}.
     * @see #mark
     */
    release(marker: number): void;
    /**
     * Return the index into the stream of the input symbol referred to by
     * {@code LA(1)}.
     *
     * <p>The behavior of this method is unspecified if no call to an
     * {@link IntStream initializing method} has occurred after this stream was
     * constructed.</p>
     */
    readonly index: number;
    /**
     * Set the input cursor to the position indicated by {@code index}. If the
     * specified index lies past the end of the stream, the operation behaves as
     * though {@code index} was the index of the EOF symbol. After this method
     * returns without throwing an exception, then at least one of the following
     * will be true.
     *
     * <ul>
     *   <li>`index` will return the index of the first symbol
     *     appearing at or after the specified {@code index}. Specifically,
     *     implementations which filter their sources should automatically
     *     adjust {@code index} forward the minimum amount required for the
     *     operation to target a non-ignored symbol.</li>
     *   <li>{@code LA(1)} returns {@link #EOF}</li>
     * </ul>
     *
     * This operation is guaranteed to not throw an exception if {@code index}
     * lies within a marked region. For more information on marked regions, see
     * {@link #mark}. The behavior of this method is unspecified if no call to
     * an {@link IntStream initializing method} has occurred after this stream
     * was constructed.
     *
     * @param index The absolute index to seek to.
     *
     * @throws IllegalArgumentException if {@code index} is less than 0
     * @throws UnsupportedOperationException if the stream does not support
     * seeking to the specified index
     */
    seek(index: number): void;
    /**
     * Returns the total number of symbols in the stream, including a single EOF
     * symbol.
     *
     * @throws UnsupportedOperationException if the size of the stream is
     * unknown.
     */
    readonly size: number;
    /**
     * Gets the name of the underlying symbol source. This method returns a
     * non-null, non-empty string. If such a name is not known, this method
     * returns {@link #UNKNOWN_SOURCE_NAME}.
     */
    readonly sourceName: string;
}