org.antlr.v4.runtime.TokenStream Maven / Gradle / Ivy
/*
* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
package org.antlr.v4.runtime;
import org.antlr.v4.runtime.misc.Interval;
/**
* An {@link IntStream} whose symbols are {@link Token} instances.
*/
public interface TokenStream extends IntStream {
/**
* Get the {@link Token} instance associated with the value returned by
* {@link #LA LA(k)}. This method has the same pre- and post-conditions as
* {@link IntStream#LA}. In addition, when the preconditions of this method
* are met, the return value is non-null and the value of
* {@code LT(k).getType()==LA(k)}.
*
* @see IntStream#LA
*/
public Token LT(int k);
/**
* Gets the {@link Token} at the specified {@code index} in the stream. When
* the preconditions of this method are met, the return value is non-null.
*
* The preconditions for this method are the same as the preconditions of
* {@link IntStream#seek}. If the behavior of {@code seek(index)} is
* unspecified for the current state and given {@code index}, then the
* behavior of this method is also unspecified.
*
* The symbol referred to by {@code index} differs from {@code seek()} only
* in the case of filtering streams where {@code index} lies before the end
* of the stream. Unlike {@code seek()}, this method does not adjust
* {@code index} to point to a non-ignored symbol.
*
* @throws IllegalArgumentException if {code index} is less than 0
* @throws UnsupportedOperationException if the stream does not support
* retrieving the token at the specified index
*/
public Token get(int index);
/**
* Gets the underlying {@link TokenSource} which provides tokens for this
* stream.
*/
public TokenSource getTokenSource();
/**
* Return the text of all tokens within the specified {@code interval}. This
* method behaves like the following code (including potential exceptions
* for violating preconditions of {@link #get}, but may be optimized by the
* specific implementation.
*
*
* TokenStream stream = ...;
* String text = "";
* for (int i = interval.a; i <= interval.b; i++) {
* text += stream.get(i).getText();
* }
*
*
* @param interval The interval of tokens within this stream to get text
* for.
* @return The text of all tokens within the specified interval in this
* stream.
*
* @throws NullPointerException if {@code interval} is {@code null}
*/
public String getText(Interval interval);
/**
* Return the text of all tokens in the stream. This method behaves like the
* following code, including potential exceptions from the calls to
* {@link IntStream#size} and {@link #getText(Interval)}, but may be
* optimized by the specific implementation.
*
*
* TokenStream stream = ...;
* String text = stream.getText(new Interval(0, stream.size()));
*
*
* @return The text of all tokens in the stream.
*/
public String getText();
/**
* Return the text of all tokens in the source interval of the specified
* context. This method behaves like the following code, including potential
* exceptions from the call to {@link #getText(Interval)}, but may be
* optimized by the specific implementation.
*
* If {@code ctx.getSourceInterval()} does not return a valid interval of
* tokens provided by this stream, the behavior is unspecified.
*
*
* TokenStream stream = ...;
* String text = stream.getText(ctx.getSourceInterval());
*
*
* @param ctx The context providing the source interval of tokens to get
* text for.
* @return The text of all tokens within the source interval of {@code ctx}.
*/
public String getText(RuleContext ctx);
/**
* Return the text of all tokens in this stream between {@code start} and
* {@code stop} (inclusive).
*
* If the specified {@code start} or {@code stop} token was not provided by
* this stream, or if the {@code stop} occurred before the {@code start}
* token, the behavior is unspecified.
*
* For streams which ensure that the {@link Token#getTokenIndex} method is
* accurate for all of its provided tokens, this method behaves like the
* following code. Other streams may implement this method in other ways
* provided the behavior is consistent with this at a high level.
*
*
* TokenStream stream = ...;
* String text = "";
* for (int i = start.getTokenIndex(); i <= stop.getTokenIndex(); i++) {
* text += stream.get(i).getText();
* }
*
*
* @param start The first token in the interval to get text for.
* @param stop The last token in the interval to get text for (inclusive).
* @return The text of all tokens lying between the specified {@code start}
* and {@code stop} tokens.
*
* @throws UnsupportedOperationException if this stream does not support
* this method for the specified tokens
*/
public String getText(Token start, Token stop);
}