BoundStar.java

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package org.apache.doris.nereids.trees.expressions;

import org.apache.doris.nereids.analyzer.UnboundSlot;
import org.apache.doris.nereids.trees.expressions.functions.PropagateNullable;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;

import com.google.common.base.Preconditions;

import java.util.List;
import java.util.stream.Collectors;

/** BoundStar is used to wrap list of slots for temporary. */
public class BoundStar extends NamedExpression implements PropagateNullable {
    public BoundStar(List<Slot> children) {
        super((List) children);
        Preconditions.checkArgument(children.stream().noneMatch(slot -> slot instanceof UnboundSlot),
                "BoundStar can not wrap UnboundSlot"
        );
    }

    public String computeToSql() {
        return children.stream().map(Expression::toSql).collect(Collectors.joining(", "));
    }

    @SuppressWarnings({"unchecked", "rawtypes"})
    public List<Slot> getSlots() {
        return (List) children();
    }

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