MaxMap.java

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

import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.types.DataType;
import org.apache.doris.nereids.types.DecimalV2Type;
import org.apache.doris.nereids.types.DecimalV3Type;

import com.google.common.base.Preconditions;

import java.util.List;

/** AggregateFunction 'max_map'. */
public class MaxMap extends MapAggregateFunction {

    public MaxMap(Expression arg) {
        this(false, arg);
    }

    public MaxMap(boolean distinct, Expression arg) {
        super("max_map", distinct, arg);
    }

    private MaxMap(AggregateFunctionParams functionParams) {
        super(functionParams);
    }

    @Override
    protected DataType argumentValueType(DataType valueType) {
        return normalizeValueType(valueType);
    }

    @Override
    protected DataType returnValueType(DataType valueType) {
        return normalizeValueType(valueType);
    }

    private static DataType normalizeValueType(DataType valueType) {
        if (valueType instanceof DecimalV2Type) {
            return DecimalV3Type.forType(valueType);
        }
        return valueType;
    }

    @Override
    public MaxMap withDistinctAndChildren(boolean distinct, List<Expression> children) {
        Preconditions.checkArgument(children.size() == 1);
        return new MaxMap(getFunctionParams(distinct, children));
    }
}