com.google.zetasql.resolvedast.ResolvedNode Maven / Gradle / Ivy
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/*
* Copyright 2019 ZetaSQL Authors
*
* 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 com.google.zetasql.resolvedast;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.protobuf.Message;
import com.google.zetasql.AnyResolvedNodeProto;
import com.google.zetasql.FileDescriptorSetsBuilder;
import com.google.zetasql.ZetaSQLResolvedNodeKind.ResolvedNodeKind;
import com.google.zetasql.ResolvedNodeProto;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
/**
* This is the base class for the resolved AST. Subclasses are in the generated file
* ResolvedNodes.java. ResolvedNodeKind enum is in the generated file resolved_node_kind.proto.
* See gen_resolved_ast.py.
*
* View code generated classes at (broken link).
* HTML documentation for the class hierarchy is generated in resolved_ast.html.
* A viewable copy is available at (broken link).
*
*
In this hierarchy, classes are either abstract or leaves.
*/
public abstract class ResolvedNode implements Serializable {
ResolvedNode(ResolvedNodeProto proto, DeserializationHelper helper) {
// Nothing to deserialize for now.
}
ResolvedNode() {}
/**
* Deserializes {@code proto} into a sub class of {@link ResolvedNode}. The
* {@link DeserializationHelper} is used to deserialize types which are passed by reference. This
* should only be used by the ZetaSQL implementation.
*/
public static ResolvedNode deserialize(AnyResolvedNodeProto proto, DeserializationHelper helper) {
return ResolvedNodes.deserialize(proto, helper);
}
/**
* Base case for recursive call in derived AST nodes.
*/
public Message serialize(
@SuppressWarnings("unused") FileDescriptorSetsBuilder fileDescriptorSetsBuilder) {
return ResolvedNodeProto.newBuilder().build();
}
public abstract ResolvedNodeKind nodeKind();
public abstract String nodeKindString();
/** Accepts a visitor, which can process the node and optionally redispatch to children. */
public abstract void accept(ResolvedNodes.Visitor visitor);
/**
* Accepts a visitor, dispatching to the children of this node.
*
*
Note: this function is made non-abstract to allow all generated ResolvedNode implementations
* to perform a {@code super.acceptChildren} call, which ensures all children nodes are sent to
* {@code visitor}.
*/
protected void acceptChildren(ResolvedNodes.Visitor visitor) {}
/**
* Creates a Builder object from this node.
*
*
The returned builder is a distinct object; modifications to the builder do not change this
* object.
*/
public abstract Builder toBuilder();
/**
* A builder class corresponding to ResolvedNode.
*
*
Note, there is a 'Builder' class hierarchy that matches the node class hierarchy found in {@
* link ResolvedNodes}.
*
*
This is declared such that you can chain 'setX' calls freely between a class and those
* classes it extends (transitively). Example:
* // Note: ResolvedArgumentRef extends ResolvedExpr
* ResolvedArgumentRef ref =
* ResolvedArgumentRef.newBuilder()
* .setArgumentKind(...) // A field on ResolvedArgumentRef
* .setType(...) // A field on ResolvedExpr
* .setName("name") // A field on ResolvedArgumentRef
* .build();
* Propagating 'is_ordered': Some setters will 'propagate' the 'is_ordered' field,
* example: {@link ResolvedNodes.ResolvedLimitOffsetScan#setInputScan}. The setters will will be
* documented as such.
*
*
Optional fields: Nearly all fields are required, and must have a non-null value. A small
* number of fields are optional and have default values.
*/
public abstract static class Builder {
/**
* Create this object.
*
* @throws IllegalArgumentException if any required field is not set.
*/
public abstract ResolvedNode build();
/**
* Validates that each required field is set.
*
* @throws IllegalArgumentException if any required field is not set.
*/
void validate() {}
}
@Override
public final String toString() {
return debugString();
}
/** Class used to collect all fields that should be printed in debugString. */
static class DebugStringField {
// If name is non-empty, "=" will be printed in front of the values.
private final String name;
// One of the two fields below will be filled in.
// If nodes is non-empty, all nodes are non-NULL.
private final String value; // Print this value directly.
private final ImmutableList nodes; // Print debugString for these nodes.
DebugStringField(String name, String value) {
this.name = Preconditions.checkNotNull(name);
this.value = Preconditions.checkNotNull(value);
this.nodes = ImmutableList.of();
}
DebugStringField(String name, ImmutableList nodes) {
this.name = Preconditions.checkNotNull(name);
this.value = null;
this.nodes = Preconditions.checkNotNull(nodes);
}
DebugStringField(String name, ResolvedNode node) {
this.name = Preconditions.checkNotNull(name);
this.value = null;
this.nodes = ImmutableList.of(node);
}
}
public final String debugString() {
StringBuilder sb = new StringBuilder();
debugStringImpl("", "", sb);
return sb.toString();
}
/**
* Print the tree recursively. The implementation is nearly identical to the C++ implementation in
* ResolvedNode::DebugStringImpl. The outputs need to be identical so the implementations should
* be kept similar to make changes to the output easier.
*
* @param prefix1 is the indentation to attach to child nodes.
* @param prefix2 is the indentation to attach to the root of this tree.
* @param sb is the output StringBuilder
*/
private void debugStringImpl(String prefix1, String prefix2, StringBuilder sb) {
List fields = new ArrayList<>();
collectDebugStringFields(fields);
// Use multiline DebugString format if any of the fields are ResolvedNodes.
boolean multiline = false;
for (DebugStringField field : fields) {
if (!field.nodes.isEmpty()) {
multiline = true;
break;
}
}
sb.append(prefix2).append(getNameForDebugString());
if (fields.isEmpty()) {
sb.append("\n");
} else if (multiline) {
sb.append("\n");
for (DebugStringField field : fields) {
boolean printFieldName = !field.name.isEmpty();
boolean printOneLine = field.nodes.isEmpty();
if (printFieldName) {
sb.append(prefix1).append("+-").append(field.name).append("=");
if (printOneLine) {
sb.append(field.value);
}
sb.append("\n");
} else if (printOneLine) {
sb.append(prefix1).append("+-").append(field.value).append("\n");
}
if (!printOneLine) {
for (ResolvedNode node : field.nodes) {
Preconditions.checkState(node != null);
String fieldNameIndent =
printFieldName ? (field != fields.get(fields.size() - 1) ? "| " : " ") : "";
String fieldValueIndent = node != field.nodes.get(field.nodes.size() - 1) ? "| " : " ";
node.debugStringImpl(
prefix1 + fieldNameIndent + fieldValueIndent, prefix1 + fieldNameIndent + "+-", sb);
}
}
}
} else {
sb.append("(");
for (DebugStringField field : fields) {
if (field != fields.get(0)) {
sb.append(", ");
}
if (field.name.isEmpty()) {
sb.append(field.value);
} else {
sb.append(field.name).append("=").append(field.value);
}
}
sb.append(")\n");
}
}
/**
* Add all fields that should be printed in debugString to {@code fields}. Implementations should
* recursively call same method in the superclass.
*/
@SuppressWarnings("unused")
protected void collectDebugStringFields(List fields) {}
/**
* Get the name string displayed for this node in the debugString. Normally it's just
* nodeKindString(), but it can be customized.
*/
protected String getNameForDebugString() {
return nodeKindString();
}
/**
* Return true if the fields returned from collectDebugStringFields would contain any field with a
* non-empty {@code nodes} list. These are the fields that would have child nodes in the
* debugString tree.
*/
private boolean hasDebugStringFieldsWithNodes() {
List fields = new ArrayList<>();
collectDebugStringFields(fields);
for (DebugStringField field : fields) {
if (!field.nodes.isEmpty()) {
return true;
}
}
return false;
}
/**
* collectDebugStringFieldsWithNameFormat and getNameForDebugStringWithNameFormat are helpers used
* in custom format methods to format nodes as an assignment, "name := node", with node's children
* as children of this node.
*/
protected final void collectDebugStringFieldsWithNameFormat(List fields) {
Preconditions.checkArgument(fields.isEmpty());
if (hasDebugStringFieldsWithNodes()) {
fields.add(new DebugStringField("", this));
} else {
collectDebugStringFields(fields);
}
}
protected final String getNameForDebugStringWithNameFormat(String name) {
if (hasDebugStringFieldsWithNodes()) {
return name + " :=";
} else {
return name + " := " + getNameForDebugString();
}
}
}