com.hazelcast.org.apache.calcite.linq4j.tree.Blocks Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License, Version 2.0
* (the "License"); you may not use this file except in com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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.hazelcast.org.apache.calcite.linq4j.tree;
/**
* Helper methods concerning {@link BlockStatement}s.
*
* @see BlockBuilder
*/
public final class Blocks {
private Blocks() {
throw new AssertionError("no blocks for you!");
}
private static BlockStatement toFunctionBlock(Node body, boolean function) {
if (body instanceof BlockStatement) {
return (BlockStatement) body;
}
Statement statement;
if (body instanceof Statement) {
statement = (Statement) body;
} else if (body instanceof Expression) {
if (((Expression) body).getType() == Void.TYPE && function) {
statement = Expressions.statement((Expression) body);
} else {
statement = Expressions.return_(null, (Expression) body);
}
} else {
throw new AssertionError("block cannot contain node that is neither "
+ "statement nor expression: " + body);
}
return Expressions.block(statement);
}
public static BlockStatement toFunctionBlock(Node body) {
return toFunctionBlock(body, true);
}
public static BlockStatement toBlock(Node body) {
return toFunctionBlock(body, false);
}
/**
* Prepends a statement to a block.
*/
public static BlockStatement create(Statement statement,
BlockStatement block) {
return Expressions.block(
Expressions.list(statement).appendAll(block.statements));
}
/**
* Converts a simple "{ return expr; }" block into "expr"; otherwise
* throws.
*/
public static Expression simple(BlockStatement block) {
if (block.statements.size() == 1) {
Statement statement = block.statements.get(0);
if (statement instanceof GotoStatement) {
return ((GotoStatement) statement).expression;
}
}
throw new AssertionError("not a simple block: " + block);
}
}