/*
* [The "BSD license"]
* Copyright (c) 2012 Terence Parr
* Copyright (c) 2012 Sam Harwell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.antlr.v4.runtime;
import org.antlr.v4.runtime.misc.Interval;
import org.antlr.v4.runtime.misc.Nullable;
import org.antlr.v4.runtime.tree.ErrorNode;
import org.antlr.v4.runtime.tree.ErrorNodeImpl;
import org.antlr.v4.runtime.tree.ParseTree;
import org.antlr.v4.runtime.tree.ParseTreeListener;
import org.antlr.v4.runtime.tree.TerminalNode;
import org.antlr.v4.runtime.tree.TerminalNodeImpl;
import org.antlr.v4.runtime.tree.pattern.RuleTagToken;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/** A rule invocation record for parsing.
*
* Contains all of the information about the current rule not stored in the
* RuleContext. It handles parse tree children list, Any ATN state
* tracing, and the default values available for rule indications:
* start, stop, rule index, current alt number, current
* ATN state.
*
* Subclasses made for each rule and grammar track the parameters,
* return values, locals, and labels specific to that rule. These
* are the objects that are returned from rules.
*
* Note text is not an actual field of a rule return value; it is computed
* from start and stop using the input stream's toString() method. I
* could add a ctor to this so that we can pass in and store the input
* stream, but I'm not sure we want to do that. It would seem to be undefined
* to get the .text property anyway if the rule matches tokens from multiple
* input streams.
*
* I do not use getters for fields of objects that are used simply to
* group values such as this aggregate. The getters/setters are there to
* satisfy the superclass interface.
*/
public class ParserRuleContext extends RuleContext {
/** If we are debugging or building a parse tree for a visitor,
* we need to track all of the tokens and rule invocations associated
* with this rule's context. This is empty for parsing w/o tree constr.
* operation because we don't the need to track the details about
* how we parse this rule.
*/
public List<ParseTree> children;
/** For debugging/tracing purposes, we want to track all of the nodes in
* the ATN traversed by the parser for a particular rule.
* This list indicates the sequence of ATN nodes used to match
* the elements of the children list. This list does not include
* ATN nodes and other rules used to match rule invocations. It
* traces the rule invocation node itself but nothing inside that
* other rule's ATN submachine.
*
* There is NOT a one-to-one correspondence between the children and
* states list. There are typically many nodes in the ATN traversed
* for each element in the children list. For example, for a rule
* invocation there is the invoking state and the following state.
*
* The parser setState() method updates field s and adds it to this list
* if we are debugging/tracing.
*
* This does not trace states visited during prediction.
*/
// public List<Integer> states;
public Token start, stop;
/**
* The exception that forced this rule to return. If the rule successfully
* completed, this is {@code null}.
*/
public RecognitionException exception;
public ParserRuleContext() { }
/** COPY a ctx (I'm deliberately not using copy constructor) */
public void copyFrom(ParserRuleContext ctx) {
// from RuleContext
this.parent = ctx.parent;
this.invokingState = ctx.invokingState;
this.start = ctx.start;
this.stop = ctx.stop;
}
public ParserRuleContext(@Nullable ParserRuleContext parent, int invokingStateNumber) {
super(parent, invokingStateNumber);
}
// Double dispatch methods for listeners
public void enterRule(ParseTreeListener listener) { }
public void exitRule(ParseTreeListener listener) { }
/** Does not set parent link; other add methods do that */
public TerminalNode addChild(TerminalNode t) {
if ( children==null ) children = new ArrayList<ParseTree>();
children.add(t);
return t;
}
public RuleContext addChild(RuleContext ruleInvocation) {
if ( children==null ) children = new ArrayList<ParseTree>();
children.add(ruleInvocation);
return ruleInvocation;
}
/** Used by enterOuterAlt to toss out a RuleContext previously added as
* we entered a rule. If we have # label, we will need to remove
* generic ruleContext object.
*/
public void removeLastChild() {
if ( children!=null ) {
children.remove(children.size()-1);
}
}
// public void trace(int s) {
// if ( states==null ) states = new ArrayList<Integer>();
// states.add(s);
// }
public TerminalNode addChild(Token matchedToken) {
TerminalNodeImpl t = new TerminalNodeImpl(matchedToken);
addChild(t);
t.parent = this;
return t;
}
public ErrorNode addErrorNode(Token badToken) {
ErrorNodeImpl t = new ErrorNodeImpl(badToken);
addChild(t);
t.parent = this;
return t;
}
@Override
/** Override to make type more specific */
public ParserRuleContext getParent() {
return (ParserRuleContext)super.getParent();
}
@Override
public ParseTree getChild(int i) {
return children!=null && i>=0 && i<children.size() ? children.get(i) : null;
}
public <T extends ParseTree> T getChild(Class<? extends T> ctxType, int i) {
if ( children==null || i < 0 || i >= children.size() ) {
return null;
}
int j = -1; // what element have we found with ctxType?
for (ParseTree o : children) {
if ( ctxType.isInstance(o) ) {
j++;
if ( j == i ) {
return ctxType.cast(o);
}
}
}
return null;
}
public TerminalNode getToken(int ttype, int i) {
if ( children==null || i < 0 || i >= children.size() ) {
return null;
}
int j = -1; // what token with ttype have we found?
for (ParseTree o : children) {
if ( o instanceof TerminalNode ) {
TerminalNode tnode = (TerminalNode)o;
Token symbol = tnode.getSymbol();
if ( symbol.getType()==ttype ) {
j++;
if ( j == i ) {
return tnode;
}
}
}
}
return null;
}
public List<TerminalNode> getTokens(int ttype) {
if ( children==null ) {
return Collections.emptyList();
}
List<TerminalNode> tokens = null;
for (ParseTree o : children) {
if ( o instanceof TerminalNode ) {
TerminalNode tnode = (TerminalNode)o;
Token symbol = tnode.getSymbol();
if ( symbol.getType()==ttype ) {
if ( tokens==null ) {
tokens = new ArrayList<TerminalNode>();
}
tokens.add(tnode);
}
}
}
if ( tokens==null ) {
return Collections.emptyList();
}
return tokens;
}
public <T extends ParserRuleContext> T getRuleContext(Class<? extends T> ctxType, int i) {
return getChild(ctxType, i);
}
public <T extends ParserRuleContext> List<T> getRuleContexts(Class<? extends T> ctxType) {
if ( children==null ) {
return Collections.emptyList();
}
List<T> contexts = null;
for (ParseTree o : children) {
if ( ctxType.isInstance(o) ) {
if ( contexts==null ) {
contexts = new ArrayList<T>();
}
contexts.add(ctxType.cast(o));
}
}
if ( contexts==null ) {
return Collections.emptyList();
}
return contexts;
}
@Override
public int getChildCount() { return children!=null ? children.size() : 0; }
@Override
public Interval getSourceInterval() {
if ( start==null || stop==null ) return Interval.INVALID;
return Interval.of(start.getTokenIndex(), stop.getTokenIndex());
}
public Token getStart() { return start; }
public Token getStop() { return stop; }
/** Used for rule context info debugging during parse-time, not so much for ATN debugging */
public String toInfoString(Parser recognizer) {
List<String> rules = recognizer.getRuleInvocationStack(this);
Collections.reverse(rules);
return "ParserRuleContext"+rules+"{" +
"start=" + start +
", stop=" + stop +
'}';
}
}