com.hazelcast.org.apache.calcite.sql.fun.SqlJsonArrayFunction 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 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.hazelcast.org.apache.calcite.sql.fun;
import com.hazelcast.org.apache.calcite.sql.SqlCall;
import com.hazelcast.org.apache.calcite.sql.SqlFunction;
import com.hazelcast.org.apache.calcite.sql.SqlFunctionCategory;
import com.hazelcast.org.apache.calcite.sql.SqlJsonConstructorNullClause;
import com.hazelcast.org.apache.calcite.sql.SqlKind;
import com.hazelcast.org.apache.calcite.sql.SqlLiteral;
import com.hazelcast.org.apache.calcite.sql.SqlNode;
import com.hazelcast.org.apache.calcite.sql.SqlOperandCountRange;
import com.hazelcast.org.apache.calcite.sql.SqlWriter;
import com.hazelcast.org.apache.calcite.sql.parser.SqlParserPos;
import com.hazelcast.org.apache.calcite.sql.type.InferTypes;
import com.hazelcast.org.apache.calcite.sql.type.OperandTypes;
import com.hazelcast.org.apache.calcite.sql.type.ReturnTypes;
import com.hazelcast.org.apache.calcite.sql.type.SqlOperandCountRanges;
import com.hazelcast.org.apache.calcite.sql.type.SqlOperandTypeChecker;
import com.hazelcast.org.apache.calcite.sql.validate.SqlValidator;
import com.hazelcast.org.checkerframework.checker.nullness.qual.Nullable;
import java.util.Locale;
import static java.util.Objects.requireNonNull;
/**
* The JSON_ARRAY
function.
*/
public class SqlJsonArrayFunction extends SqlFunction {
public SqlJsonArrayFunction() {
super("JSON_ARRAY", SqlKind.OTHER_FUNCTION, ReturnTypes.VARCHAR_2000,
InferTypes.ANY_NULLABLE, OperandTypes.VARIADIC, SqlFunctionCategory.SYSTEM);
}
@Override public SqlOperandCountRange getOperandCountRange() {
return SqlOperandCountRanges.from(1);
}
@Override protected void checkOperandCount(SqlValidator validator,
@Nullable SqlOperandTypeChecker argType, SqlCall call) {
assert call.operandCount() >= 1;
}
@Override public SqlCall createCall(@Nullable SqlLiteral functionQualifier,
SqlParserPos pos, @Nullable SqlNode... operands) {
if (operands[0] == null) {
operands[0] =
SqlLiteral.createSymbol(SqlJsonConstructorNullClause.ABSENT_ON_NULL,
pos);
}
return super.createCall(functionQualifier, pos, operands);
}
@Override public @Nullable String getSignatureTemplate(int operandsCount) {
assert operandsCount >= 1;
final StringBuilder sb = new StringBuilder();
sb.append("{0}(");
for (int i = 1; i < operandsCount; i++) {
sb.append(String.format(Locale.ROOT, "{%d} ", i + 1));
}
sb.append("{1})");
return sb.toString();
}
@Override public void unparse(SqlWriter writer, SqlCall call, int leftPrec,
int rightPrec) {
assert call.operandCount() >= 1;
final SqlWriter.Frame frame = writer.startFunCall(getName());
SqlWriter.Frame listFrame = writer.startList("", "");
for (int i = 1; i < call.operandCount(); i++) {
writer.sep(",");
call.operand(i).unparse(writer, leftPrec, rightPrec);
}
writer.endList(listFrame);
SqlJsonConstructorNullClause nullClause = getEnumValue(call.operand(0));
switch (nullClause) {
case ABSENT_ON_NULL:
writer.keyword("ABSENT ON NULL");
break;
case NULL_ON_NULL:
writer.keyword("NULL ON NULL");
break;
default:
throw new IllegalStateException("unreachable code");
}
writer.endFunCall(frame);
}
@SuppressWarnings("unchecked")
private static > E getEnumValue(SqlNode operand) {
return (E) requireNonNull(((SqlLiteral) operand).getValue(), "operand.value");
}
}
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