io.prestosql.sql.planner.iterative.rule.DesugarCurrentUser.java Source code

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Here is the source code for io.prestosql.sql.planner.iterative.rule.DesugarCurrentUser.java

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/*
 * 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 io.prestosql.sql.planner.iterative.rule;

import com.google.common.collect.ImmutableList;
import io.prestosql.sql.tree.CurrentUser;
import io.prestosql.sql.tree.Expression;
import io.prestosql.sql.tree.ExpressionTreeRewriter;
import io.prestosql.sql.tree.FunctionCall;
import io.prestosql.sql.tree.QualifiedName;

public class DesugarCurrentUser extends ExpressionRewriteRuleSet {
    public DesugarCurrentUser() {
        super(createRewrite());
    }

    private static ExpressionRewriter createRewrite() {
        return (expression, context) -> ExpressionTreeRewriter
                .rewriteWith(new io.prestosql.sql.tree.ExpressionRewriter<Void>() {
                    @Override
                    public Expression rewriteCurrentUser(CurrentUser node, Void context,
                            ExpressionTreeRewriter<Void> treeRewriter) {
                        return DesugarCurrentUser.getCall(node);
                    }
                }, expression);
    }

    public static FunctionCall getCall(CurrentUser node) {
        return new FunctionCall(QualifiedName.of("$current_user"), ImmutableList.of());
    }
}