ArrayEnumerateUniq.java

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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.shape.BinaryExpression;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
import org.apache.doris.nereids.types.ArrayType;
import org.apache.doris.nereids.types.BigIntType;
import org.apache.doris.nereids.types.coercion.AnyDataType;
import org.apache.doris.nereids.util.ExpressionUtils;

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

import java.util.List;

/**
 * ScalarFunction 'array_enumerate_uniq'.
 *  more than 0 array as args
 */
public class ArrayEnumerateUniq extends ScalarFunction
        implements BinaryExpression, ExplicitlyCastableSignature, PropagateNullable {

    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
            FunctionSignature.ret(ArrayType.of(BigIntType.INSTANCE))
                    .varArgs(ArrayType.of(AnyDataType.INSTANCE_WITHOUT_INDEX))
    );

    /**
     * constructor with more than 0 arguments.
     */
    public ArrayEnumerateUniq(Expression arg, Expression ...varArgs) {
        super("array_enumerate_uniq", ExpressionUtils.mergeArguments(arg, varArgs));
    }

    /**
     * withChildren.
     */
    @Override
    public ArrayEnumerateUniq withChildren(List<Expression> children) {
        Preconditions.checkArgument(!children.isEmpty());
        return new ArrayEnumerateUniq(children.get(0), children.subList(1, children.size()).toArray(new Expression[0]));
    }

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

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

}