MinBy.java

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

import org.apache.doris.catalog.FunctionSignature;
import org.apache.doris.catalog.Type;
import org.apache.doris.nereids.exceptions.AnalysisException;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
import org.apache.doris.nereids.trees.expressions.shape.BinaryExpression;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
import org.apache.doris.nereids.types.coercion.AnyDataType;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;

import java.util.List;

/**
 * AggregateFunction 'min_by'. This class is generated by GenerateFunction.
 */
public class MinBy extends NullableAggregateFunction
        implements BinaryExpression, ExplicitlyCastableSignature {

    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
            FunctionSignature.retArgType(0).args(AnyDataType.INSTANCE_WITHOUT_INDEX, AnyDataType.INSTANCE_WITHOUT_INDEX)
    );

    /**
     * constructor with 2 arguments.
     */
    public MinBy(Expression arg0, Expression arg1) {
        this(false, false, arg0, arg1);
    }

    /**
     * constructor with 2 arguments.
     */
    public MinBy(boolean distinct, Expression arg0, Expression arg1) {
        this(distinct, false, arg0, arg1);
    }

    private MinBy(boolean distinct, boolean alwaysNullable, Expression arg0, Expression arg1) {
        super("min_by", distinct, alwaysNullable, arg0, arg1);
    }

    @Override
    public void checkLegalityBeforeTypeCoercion() {
        if (getArgumentType(1).isOnlyMetricType()) {
            throw new AnalysisException(Type.OnlyMetricTypeErrorMsg);
        }
    }

    /**
     * withDistinctAndChildren.
     */
    @Override
    public MinBy withDistinctAndChildren(boolean distinct, List<Expression> children) {
        Preconditions.checkArgument(children.size() == 2);
        return new MinBy(distinct, alwaysNullable, children.get(0), children.get(1));
    }

    @Override
    public NullableAggregateFunction withAlwaysNullable(boolean alwaysNullable) {
        return new MinBy(distinct, alwaysNullable, children.get(0), children.get(1));
    }

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

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