ArrayJoin.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.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.functions.PropagateNullable;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
import org.apache.doris.nereids.types.ArrayType;
import org.apache.doris.nereids.types.DataType;
import org.apache.doris.nereids.types.StringType;
import org.apache.doris.nereids.types.VarcharType;
import org.apache.doris.nereids.types.coercion.AnyDataType;

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

import java.util.List;

/**
 * ScalarFunction 'array_join'. This class is generated by GenerateFunction.
 */
public class ArrayJoin extends ScalarFunction
        implements ExplicitlyCastableSignature, PropagateNullable {

    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
            FunctionSignature.ret(StringType.INSTANCE)
                    .args(ArrayType.of(AnyDataType.INSTANCE_WITHOUT_INDEX), VarcharType.SYSTEM_DEFAULT),
            FunctionSignature.ret(StringType.INSTANCE)
                    .args(ArrayType.of(AnyDataType.INSTANCE_WITHOUT_INDEX),
                            VarcharType.SYSTEM_DEFAULT, VarcharType.SYSTEM_DEFAULT)
    );

    /**
     * constructor with 2 arguments.
     */
    public ArrayJoin(Expression arg0, Expression arg1) {
        super("array_join", arg0, arg1);
    }

    /**
     * constructor with 3 arguments.
     */
    public ArrayJoin(Expression arg0, Expression arg1, Expression arg2) {
        super("array_join", arg0, arg1, arg2);
    }

    @Override
    public void checkLegalityBeforeTypeCoercion() {
        DataType argType = child(0).getDataType();
        if (((ArrayType) argType).getItemType().isComplexType()) {
            throw new AnalysisException(toSql() + " does not support type: "
                                    + ((ArrayType) argType).getItemType().toString());
        }
    }

    /**
     * withChildren.
     */
    @Override
    public ArrayJoin withChildren(List<Expression> children) {
        Preconditions.checkArgument(children.size() == 2
                || children.size() == 3);
        if (children.size() == 2) {
            return new ArrayJoin(children.get(0), children.get(1));
        } else {
            return new ArrayJoin(children.get(0), children.get(1), children.get(2));
        }
    }

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

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