PreparePlaceholder.java

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// to you under the Apache License, Version 2.0 (the
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//
//   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.doris.nereids.trees.expressions.functions.scalar;

import org.apache.doris.catalog.FunctionSignature;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
import org.apache.doris.nereids.trees.expressions.functions.PropagateNullable;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
import org.apache.doris.nereids.types.IntegerType;
import org.apache.doris.nereids.types.StringType;

import com.google.common.collect.ImmutableList;

import java.util.List;

/**
 * Internal function for prepare statement only.
 */
public class PreparePlaceholder extends ScalarFunction
        implements ExplicitlyCastableSignature, PropagateNullable {

    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
            FunctionSignature.ret(StringType.INSTANCE).args(IntegerType.INSTANCE)
    );

    /**
     * constructor with 1 argument.
     */
    public PreparePlaceholder(Expression arg0) {
        super("prepare_placeholder", arg0);
    }

    @Override
    public boolean foldable() {
        return false;
    }

    @Override
    public List<FunctionSignature> getSignatures() {
        return SIGNATURES;
    }

    @Override
    public <R, C> R accept(ExpressionVisitor<R, C> visitor, C context) {
        return visitor.visitPreparePlaceholer(this, context);
    }

    @Override
    public boolean equals(Object o) {
        return this == o;
    }

    @Override
    public int hashCode() {
        return System.identityHashCode(this);
    }
}