IdenticalSignature.java

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

import org.apache.doris.catalog.FunctionSignature;
import org.apache.doris.nereids.types.DataType;
import org.apache.doris.nereids.types.coercion.AnyDataType;
import org.apache.doris.nereids.types.coercion.ComplexDataType;
import org.apache.doris.nereids.types.coercion.FollowToAnyDataType;

import java.util.List;

/**
 * Identical function signature. This class equals to 'CompareMode.IS_IDENTICAL'.
 *
 * Two signatures are identical if the number of arguments and their types match
 * exactly and signature isn't varargs.
 */
public interface IdenticalSignature extends ComputeSignature {
    /** isIdentical */
    static boolean isIdentical(DataType signatureType, DataType realType) {
        return ComputeSignature.processComplexType(
                signatureType, realType, IdenticalSignature::isPrimitiveIdentical);
    }

    /** isIdentical */
    static boolean isPrimitiveIdentical(DataType signatureType, DataType realType) {
        try {
            // TODO: copy matchesType to DataType
            // TODO: resolve AnyDataType invoke toCatalogDataType
            if (signatureType instanceof AnyDataType || signatureType instanceof FollowToAnyDataType) {
                return false;
            }
            if (signatureType instanceof ComplexDataType && !(realType instanceof ComplexDataType)) {
                return false;
            }
            return realType.toCatalogDataType().matchesType(signatureType.toCatalogDataType());
        } catch (Throwable t) {
            // the signatureType maybe DataType and can not cast to catalog data type.
            return false;
        }
    }

    @Override
    default FunctionSignature searchSignature(List<FunctionSignature> signatures) {
        return SearchSignature.from(this, signatures, getArguments())
                // first round, use identical strategy to find signature
                .orElseSearch(IdenticalSignature::isIdentical)
                .resultOrException(getName());
    }
}