/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.elasticsearch.painless.node;
import org.elasticsearch.painless.Globals;
import org.elasticsearch.painless.Locals;
import org.elasticsearch.painless.Location;
import org.elasticsearch.painless.MethodWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import static java.lang.Math.max;
import static java.util.Collections.emptyList;
/**
* The superclass for all nodes.
*/
public abstract class ANode {
/**
* The identifier of the script and character offset used for debugging and errors.
*/
final Location location;
/**
* Standard constructor with location used for error tracking.
*/
ANode(Location location) {
this.location = Objects.requireNonNull(location);
}
/**
* Adds all variable names referenced to the variable set.
* <p>
* This can be called at any time, e.g. to support lambda capture.
* @param variables set of variables referenced (any scope)
*/
abstract void extractVariables(Set<String> variables);
/**
* Checks for errors and collects data for the writing phase.
*/
abstract void analyze(Locals locals);
/**
* Writes ASM based on the data collected during the analysis phase.
*/
abstract void write(MethodWriter writer, Globals globals);
/**
* Create an error with location information pointing to this node.
*/
RuntimeException createError(RuntimeException exception) {
return location.createError(exception);
}
/**
* Subclasses should implement this with a method like {@link #singleLineToString(Object...)} or
* {@link #multilineToString(Collection, Collection)}.
*/
public abstract String toString();
// Below are utilities for building the toString
/**
* Build {@link #toString()} for a node without inserting line breaks between the sub-nodes.
*/
protected String singleLineToString(Object... subs) {
return singleLineToString(Arrays.asList(subs));
}
/**
* Build {@link #toString()} for a node without inserting line breaks between the sub-nodes.
*/
protected String singleLineToString(Collection<? extends Object> subs) {
return joinWithName(getClass().getSimpleName(), subs, emptyList());
}
/**
* Build {@link #toString()} for a node that optionally ends in {@code (Args some arguments here)}. Usually function calls.
*/
protected String singleLineToStringWithOptionalArgs(Collection<? extends ANode> arguments, Object... restOfSubs) {
List<Object> subs = new ArrayList<>();
Collections.addAll(subs, restOfSubs);
if (false == arguments.isEmpty()) {
subs.add(joinWithName("Args", arguments, emptyList()));
}
return singleLineToString(subs);
}
/**
* Build {@link #toString()} for a node that should have new lines after some of its sub-nodes.
*/
protected String multilineToString(Collection<? extends Object> sameLine, Collection<? extends Object> ownLine) {
return joinWithName(getClass().getSimpleName(), sameLine, ownLine);
}
/**
* Zip two (potentially uneven) lists together into for {@link #toString()}.
*/
protected List<String> pairwiseToString(Collection<? extends Object> lefts, Collection<? extends Object> rights) {
List<String> pairs = new ArrayList<>(max(lefts.size(), rights.size()));
Iterator<? extends Object> left = lefts.iterator();
Iterator<? extends Object> right = rights.iterator();
while (left.hasNext() || right.hasNext()) {
pairs.add(joinWithName("Pair",
Arrays.asList(left.hasNext() ? left.next() : "<uneven>", right.hasNext() ? right.next() : "<uneven>"),
emptyList()));
}
return pairs;
}
/**
* Build a {@link #toString()} for some expressions. Usually best to use {@link #singleLineToString(Object...)} or
* {@link #multilineToString(Collection, Collection)} instead because they include the name of the node by default.
*/
protected String joinWithName(String name, Collection<? extends Object> sameLine,
Collection<? extends Object> ownLine) {
StringBuilder b = new StringBuilder();
b.append('(').append(name);
for (Object sub : sameLine) {
b.append(' ').append(sub);
}
if (ownLine.size() == 1 && sameLine.isEmpty()) {
b.append(' ').append(ownLine.iterator().next());
} else {
for (Object sub : ownLine) {
b.append("\n ").append(Objects.toString(sub).replace("\n", "\n "));
}
}
return b.append(')').toString();
}
}