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	/*
	* Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package java.lang.invoke;

	import java.util.List;

	/**
	* An entity that has a type descriptor.
	*
	* @since 12
	*/
	public interface TypeDescriptor {
	/**
	* Returns the descriptor string for this {@code TypeDescriptor} object.
	*
	* If this {@code TypeDescriptor} object can be described in nominal form,
	* then this method returns a type descriptor as specified in JVMS {@jvms 4.3}.
	* The result descriptor string can be used to produce
	* a {@linkplain java.lang.constant.ConstantDesc nominal descriptor}.
	*
	* Otherwise, the result string is not a type descriptor.
	* No {@linkplain java.lang.constant.ConstantDesc nominal descriptor}
	* can be produced from the result string.
	*
	* @return the descriptor string for this {@code TypeDescriptor} object
	* @jvms 4.3.2 Field Descriptors
	* @jvms 4.3.3 Method Descriptors
	*/
	String descriptorString();


	/**
	* An entity that has a field type descriptor.
	* Field descriptors conforming to JVMS {@jvms 4.3.2} can be described
	* nominally via {@link Class#describeConstable Class::describeConstable};
	* otherwise they cannot be described nominally.
	*
	* @param <F> the class implementing {@linkplain TypeDescriptor.OfField}
	* @jvms 4.3.2 Field Descriptors
	* @since 12
	*/
	interface OfField<F extends TypeDescriptor.OfField<F>> extends TypeDescriptor {
	/**
	* Does this field descriptor describe an array type?
	* @return whether this field descriptor describes an array type
	*/
	boolean isArray();

	/**
	* Does this field descriptor describe a primitive type (including void.)
	*
	* @return whether this field descriptor describes a primitive type
	*/
	boolean isPrimitive();

	/**
	* If this field descriptor describes an array type, return
	* a descriptor for its component type, otherwise return {@code null}.
	* @return the component type, or {@code null} if this field descriptor does
	* not describe an array type
	*/
	F componentType();

	/**
	* Return a descriptor for the array type whose component type is described by this
	* descriptor
	* @return the descriptor for the array type
	*/
	F arrayType();
	}


	/**
	* An entity that has a method type descriptor
	* Method descriptors conforming to JVMS {@jvms 4.3.3} can be described
	* nominally via {@link MethodType#describeConstable MethodType::describeConstable};
	* otherwise they cannot be described nominally.
	*
	* @param <F> the type representing field type descriptors
	* @param <M> the class implementing {@linkplain TypeDescriptor.OfMethod}
	* @jvms 4.3.2 Field Descriptors
	* @jvms 4.3.3 Method Descriptors
	* @since 12
	*/
	interface OfMethod<F extends TypeDescriptor.OfField<F>, M extends TypeDescriptor.OfMethod<F, M>>
	extends TypeDescriptor {

	/**
	* Return the number of parameters in the method type
	* @return the number of parameters
	*/
	int parameterCount();

	/**
	* Return a field descriptor describing the requested parameter of the method type
	* described by this descriptor
	* @param i the index of the parameter
	* @return a field descriptor for the requested parameter type
	* @throws IndexOutOfBoundsException if the index is outside the half-open
	* range {[0, parameterCount)}
	*/
	F parameterType(int i);

	/**
	* Return a field descriptor describing the return type of the method type described
	* by this descriptor
	* @return a field descriptor for the return type
	*/
	F returnType();

	/**
	* Return an array of field descriptors for the parameter types of the method type
	* described by this descriptor
	* @return field descriptors for the parameter types
	*/
	F[] parameterArray();

	/**
	* Return an immutable list of field descriptors for the parameter types of the method type
	* described by this descriptor
	* @return field descriptors for the parameter types
	*/
	List<F> parameterList();

	/**
	* Return a method descriptor that is identical to this one, except that the return
	* type has been changed to the specified type
	*
	* @param newReturn a field descriptor for the new return type
	* @throws NullPointerException if any argument is {@code null}
	* @return the new method descriptor
	*/
	M changeReturnType(F newReturn);

	/**
	* Return a method descriptor that is identical to this one,
	* except that a single parameter type has been changed to the specified type.
	*
	* @param index the index of the parameter to change
	* @param paramType a field descriptor describing the new parameter type
	* @return the new method descriptor
	* @throws NullPointerException if any argument is {@code null}
	* @throws IndexOutOfBoundsException if the index is outside the half-open
	* range {[0, parameterCount)}
	*/
	M changeParameterType(int index, F paramType);

	/**
	* Return a method descriptor that is identical to this one,
	* except that a range of parameter types have been removed.
	*
	* @param start the index of the first parameter to remove
	* @param end the index after the last parameter to remove
	* @return the new method descriptor
	*
	* @throws IndexOutOfBoundsException if {@code start} is outside the half-open
	* range {@code [0, parameterCount)}, or {@code end} is outside the closed range
	* {@code [0, parameterCount]}, or if {@code start > end}
	*/
	M dropParameterTypes(int start, int end);

	/**
	* Return a method descriptor that is identical to this one,
	* except that a range of additional parameter types have been inserted.
	*
	* @param pos the index at which to insert the first inserted parameter
	* @param paramTypes field descriptors describing the new parameter types
	* to insert
	* @return the new method descriptor
	* @throws NullPointerException if any argument is {@code null}
	* @throws IndexOutOfBoundsException if {@code pos} is outside the closed
	* range {[0, parameterCount]}
	*/
	@SuppressWarnings("unchecked")
	M insertParameterTypes(int pos, F... paramTypes);
	}
	}

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