/*
* Copyright (C) 2009-2010 Mathias Doenitz
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.parboiled;
import org.jetbrains.annotations.NotNull;
import org.parboiled.errors.InvalidInputError;
import org.parboiled.support.*;
import java.util.ArrayList;
import java.util.List;
/**
* A {@link ParseRunner} implementation that properly reports the first {@link InvalidInputError} if the input
* does not conform to the rule grammar.
* It performs exactly as the {@link BasicParseRunner} on valid input, however, on invalid input two more parsing
* runs are initiated: one for recording the first parse error and one for collecting the error report information.
*/
public class ReportingParseRunner<V> extends BasicParseRunner<V> {
/**
* Create a new ReportingParseRunner instance with the given rule and input text and returns the result of
* its {@link #run(String)} method invocation.
*
* @param rule the parser rule to run
* @param input the input text to run on
* @return the ParsingResult for the parsing run
*/
public static <V> ParsingResult<V> run(@NotNull Rule rule, @NotNull String input) {
return new ReportingParseRunner<V>(rule).run(input);
}
/**
* Creates a new ReportingParseRunner instance for the given rule.
*
* @param rule the parser rule
*/
public ReportingParseRunner(@NotNull Rule rule) {
super(rule);
}
/**
* Creates a new ReportingParseRunner instance for the given rule using the given ValueStack instance.
*
* @param rule the parser rule
* @param valueStack the value stack
*/
public ReportingParseRunner(@NotNull Rule rule, @NotNull ValueStack<V> valueStack) {
super(rule, valueStack);
}
@SuppressWarnings({"SimplifiableIfStatement"})
@Override
protected boolean runRootContext() {
// run a basic match
if (super.runRootContext()) {
return true;
}
// ok, we have a parse error, so run again without fast string matching and with our recording handler
RecordingParseRunner.Handler recordingHandler = new RecordingParseRunner.Handler();
if (runRootContext(recordingHandler, false)) {
throw new IllegalStateException(); // we failed before so we should really be failing again
}
// finally perform a third, reporting run (now that we know the error location)
Handler reportingHandler = new Handler(recordingHandler.getErrorIndex());
if (runRootContext(reportingHandler, false)) {
throw new IllegalStateException(); // we failed before so we should really be failing again
}
return false;
}
/**
* A {@link MatchHandler} implementation that reports the {@link InvalidInputError} at a given error index.
* For the actual matching this handler relies on another, inner {@link MatchHandler} instance it delegates to.
*/
public static class Handler implements MatchHandler {
private final IsSingleCharMatcherVisitor isSingleCharMatcherVisitor = new IsSingleCharMatcherVisitor();
private final int errorIndex;
private final MatchHandler inner;
private final List<MatcherPath> failedMatchers = new ArrayList<MatcherPath>();
private MatcherPath lastMatch;
private InvalidInputError parseError;
private boolean seeking;
/**
* Create a new handler that can report the {@link InvalidInputError} at the given error index.
* It relies on a new {@link BasicParseRunner.Handler} instance for the actual matching.
*
* @param errorIndex the InputLocation of the error to be reported
*/
public Handler(int errorIndex) {
this(errorIndex, new BasicParseRunner.Handler());
}
/**
* Create a new handler that can report the {@link InvalidInputError} at the given error index.
* It relies on the given {@link MatchHandler} instance for the actual matching.
*
* @param errorIndex the InputLocation of the error to be reported
* @param inner the inner MatchHandler to use
*/
public Handler(int errorIndex, @NotNull MatchHandler inner) {
this.errorIndex = errorIndex;
this.inner = inner;
}
/**
* Returns the {@link InvalidInputError} instance that was created during the reporting run.
*
* @return the InvalidInputError
*/
public InvalidInputError getParseError() {
return parseError;
}
public boolean matchRoot(MatcherContext<?> rootContext) {
failedMatchers.clear();
seeking = errorIndex > 0;
inner.matchRoot(rootContext);
parseError =
new InvalidInputError(rootContext.getInputBuffer(), errorIndex, lastMatch, failedMatchers, null);
rootContext.getParseErrors().add(parseError);
return false;
}
public boolean match(MatcherContext<?> context) {
boolean matched = inner.match(context);
if (context.getCurrentIndex() == errorIndex) {
if (matched && seeking) {
lastMatch = context.getPath();
seeking = false;
}
if (!matched && !seeking && context.getMatcher().accept(isSingleCharMatcherVisitor)) {
failedMatchers.add(context.getPath());
}
}
return matched;
}
}
}