src/java.base/share/classes/java/lang/classfile/ClassSignature.java

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package java.lang.classfile;

import java.lang.classfile.attribute.SignatureAttribute;
import java.util.List;

import jdk.internal.classfile.impl.SignaturesImpl;

import static java.util.Objects.requireNonNull;

/**
 * Models the generic signature of a class or interface, as defined by JVMS
 * {@jvms 4.7.9.1}.
 *
 * @see Class
 * @see SignatureAttribute
 * @jls 8.1 Class Declarations
 * @jls 9.1 Interface Declarations
 * @jvms 4.7.9.1 Signatures
 * @since 24
 */
public sealed interface ClassSignature
        permits SignaturesImpl.ClassSignatureImpl {

    /**
     * {@return the type parameters of this class or interface, may be empty}
     *
     * @see Class#getTypeParameters()
     * @jls 8.1.2 Generic Classes and Type Parameters
     * @jls 9.1.2 Generic Interfaces and Type Parameters
     */
    List<Signature.TypeParam> typeParameters();

    /**
     * {@return the instantiation of the superclass in this signature}
     * Interfaces return a signature representing the {@link Object} class.
     *
     * @see Class#getGenericSuperclass()
     * @jls 8.1.4 Superclasses and Subclasses
     */
    Signature.ClassTypeSig superclassSignature();

    /**
     * {@return the instantiation of the interfaces in this signature, may be
     * empty}
     *
     * @see Class#getGenericInterfaces()
     * @jls 8.1.5 Superinterfaces
     * @jls 9.1.3 Superinterfaces and Subinterfaces
     */
    List<Signature.ClassTypeSig> superinterfaceSignatures();

    /** {@return the raw signature string} */
    String signatureString();

    /**
     * {@return a class signature with no type parameter declaration}
     *
     * @param superclassSignature the superclass
     * @param superinterfaceSignatures the interfaces
     */
    public static ClassSignature of(Signature.ClassTypeSig superclassSignature,
                                    Signature.ClassTypeSig... superinterfaceSignatures) {
        return of(List.of(), superclassSignature, superinterfaceSignatures);
    }

    /**
     * {@return a class signature}
     * @param typeParameters the type parameters, may be empty
     * @param superclassSignature the superclass
     * @param superinterfaceSignatures the interfaces
     */
    public static ClassSignature of(List<Signature.TypeParam> typeParameters,
                                    Signature.ClassTypeSig superclassSignature,
                                    Signature.ClassTypeSig... superinterfaceSignatures) {
        return new SignaturesImpl.ClassSignatureImpl(
                List.copyOf(requireNonNull(typeParameters)),
                requireNonNull(superclassSignature),
                List.of(superinterfaceSignatures));
    }

    /**
     * Parses a raw class signature string into a {@linkplain Signature}.
     *
     * @param classSignature the raw class signature string
     * @return class signature
     * @throws IllegalArgumentException if the string is not a valid class signature string
     */
    public static ClassSignature parseFrom(String classSignature) {
        return new SignaturesImpl(classSignature).parseClassSignature();
    }
}