Copyright (c) 2000, 2019 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Matt Chapman, mpchapman@gmail.com - 89977 Make JDT .java agnostic
    Jesper S Møller - Bug 529432 - Allow JDT UI to target Java 10
/*******************************************************************************
 * Copyright (c) 2000, 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Matt Chapman, mpchapman@gmail.com - 89977 Make JDT .java agnostic
 *     Jesper S Møller - Bug 529432 - Allow JDT UI to target Java 10
 *******************************************************************************/
package org.eclipse.jdt.internal.corext.util;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.SubMonitor;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IStorage;

import org.eclipse.text.edits.TextEdit;

import org.eclipse.ltk.core.refactoring.resource.Resources;

import org.eclipse.jdt.core.ClasspathContainerInitializer;
import org.eclipse.jdt.core.Flags;
import org.eclipse.jdt.core.IClasspathContainer;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IField;
import org.eclipse.jdt.core.IJarEntryResource;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IMember;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.IModularClassFile;
import org.eclipse.jdt.core.IModuleDescription;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.IPackageFragmentRoot;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.ITypeHierarchy;
import org.eclipse.jdt.core.ITypeRoot;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.Signature;
import org.eclipse.jdt.core.compiler.CharOperation;

import org.eclipse.jdt.internal.core.manipulation.JavaManipulationMessages;

import org.eclipse.jdt.launching.IVMInstall;
import org.eclipse.jdt.launching.IVMInstall2;
import org.eclipse.jdt.launching.JavaRuntime;
import org.eclipse.jdt.launching.environments.IExecutionEnvironment;

Utility methods for the Java Model.
/**
 * Utility methods for the Java Model.
 */
// @see JDTUIHelperClasses
public final class JavaModelUtil {
	
	
The latest available JavaCore#VERSION_* level. 
Since:
3.7/**
	 * The latest available {@link JavaCore}{@code #VERSION_*} level.
	 * @since 3.7
	 */
	public static final String VERSION_LATEST;
	static {
		VERSION_LATEST= JavaCore.VERSION_13; // make sure it is not inlined
	}

	public static final int VALIDATE_EDIT_CHANGED_CONTENT= 10003;

	
Only use this suffix for creating new .java files. In general, use one of the three *JavaLike*(..) methods in JavaCore or create a name from an existing compilation unit with getRenamedCUName(ICompilationUnit, String) 
 Note: Unlike JavaCore.getJavaLikeExtensions(), this suffix includes a leading ".". 
See Also:
JavaCore.getJavaLikeExtensions()
JavaCore.isJavaLikeFileName(String)
JavaCore.removeJavaLikeExtension(String)
getRenamedCUName(ICompilationUnit, String)/**
	 * Only use this suffix for creating new .java files.
	 * In general, use one of the three *JavaLike*(..) methods in JavaCore or create
	 * a name from an existing compilation unit with {@link #getRenamedCUName(ICompilationUnit, String)}
	 * <p>
	 * Note: Unlike {@link JavaCore#getJavaLikeExtensions()}, this suffix includes a leading ".".
	 * </p>
	 *
	 * @see JavaCore#getJavaLikeExtensions()
	 * @see JavaCore#isJavaLikeFileName(String)
	 * @see JavaCore#removeJavaLikeExtension(String)
	 * @see #getRenamedCUName(ICompilationUnit, String)
	 */
	public static final String DEFAULT_CU_SUFFIX= ".java"; //$NON-NLS-1$

	
The name of the package-info.java file.
Since:
3.8/**
	 * The name of the package-info.java file.
	 * @since 3.8
	 */
	public static final String PACKAGE_INFO_JAVA= "package-info.java"; //$NON-NLS-1$
	
	
The name of the package-info.class file.
Since:
3.9/**
	 * The name of the package-info.class file.
	 * @since 3.9
	 */
	public static final String PACKAGE_INFO_CLASS= "package-info.class"; //$NON-NLS-1$

	
The name of the package.html file.
Since:
3.9/**
	 * The name of the package.html file.
	 * @since 3.9
	 */
	public static final String PACKAGE_HTML= "package.html"; //$NON-NLS-1$

	
The name of the module-info.java file.
Since:
3.14/**
	 * The name of the module-info.java file.
	 * @since 3.14
	 */
	public static final String MODULE_INFO_JAVA= "module-info.java"; //$NON-NLS-1$

	
The name of the module-info.class file.
Since:
3.14/**
	 * The name of the module-info.class file.
	 * @since 3.14
	 */
	public static final String MODULE_INFO_CLASS= "module-info.class"; //$NON-NLS-1$

	
Constant for the name of all unnamed modules.
Since:
3.14/**
	 * Constant for the name of all unnamed modules.
	 * @since 3.14
	 */
	public static final String ALL_UNNAMED= "ALL-UNNAMED"; //$NON-NLS-1$

	
Finds a type container by container name. The returned element will be of type
IType or a IPackageFragment. null is returned if the
type container could not be found.
Params:
jproject – The Java project defining the context to search
typeContainerName – A dot separated name of the type container
Throws:
JavaModelException – thrown when the project can not be accessed
See Also:
getTypeContainerName(IType)
Returns:
returns the container/**
	 * Finds a type container by container name. The returned element will be of type
	 * <code>IType</code> or a <code>IPackageFragment</code>. <code>null</code> is returned if the
	 * type container could not be found.
	 * 
	 * @param jproject The Java project defining the context to search
	 * @param typeContainerName A dot separated name of the type container
	 * @return returns the container
	 * @throws JavaModelException thrown when the project can not be accessed
	 * @see #getTypeContainerName(IType)
	 */
	public static IJavaElement findTypeContainer(IJavaProject jproject, String typeContainerName) throws JavaModelException {
		// try to find it as type
		IJavaElement result= jproject.findType(typeContainerName);
		if (result == null) {
			// find it as package
			IPath path= new Path(typeContainerName.replace('.', '/'));
			result= jproject.findElement(path);
			if (!(result instanceof IPackageFragment)) {
				result= null;
			}

		}
		return result;
	}

	
Finds a type in a compilation unit. Typical usage is to find the corresponding
type in a working copy.
Params:
cu – the compilation unit to search in
typeQualifiedName – the type qualified name (type name with enclosing type names (separated by dots))
Throws:
JavaModelException – thrown when the cu can not be accessed
Returns:
the type found, or null if not existing/**
	 * Finds a type in a compilation unit. Typical usage is to find the corresponding
	 * type in a working copy.
	 * @param cu the compilation unit to search in
	 * @param typeQualifiedName the type qualified name (type name with enclosing type names (separated by dots))
	 * @return the type found, or null if not existing
	 * @throws JavaModelException thrown when the cu can not be accessed
	 */
	public static IType findTypeInCompilationUnit(ICompilationUnit cu, String typeQualifiedName) throws JavaModelException {
		IType[] types= cu.getAllTypes();
		for (int i= 0; i < types.length; i++) {
			String currName= types[i].getTypeQualifiedName('.');
			if (typeQualifiedName.equals(currName)) {
				return types[i];
			}
		}
		return null;
	}

	
Returns the element of the given compilation unit which is "equal" to the
given element. Note that the given element usually has a parent different
from the given compilation unit.
Params:
cu – the cu to search in
element – the element to look for
Returns:
an element of the given cu "equal" to the given element/**
	 * Returns the element of the given compilation unit which is "equal" to the
	 * given element. Note that the given element usually has a parent different
	 * from the given compilation unit.
	 *
	 * @param cu the cu to search in
	 * @param element the element to look for
	 * @return an element of the given cu "equal" to the given element
	 */
	public static IJavaElement findInCompilationUnit(ICompilationUnit cu, IJavaElement element) {
		IJavaElement[] elements= cu.findElements(element);
		if (elements != null && elements.length > 0) {
			return elements[0];
		}
		return null;
	}

	
Returns the fully qualified name of a type's container. (package name or enclosing type name)
Params:
type – the type
Returns:
the type container name/**
	 * Returns the fully qualified name of a type's container. (package name or enclosing type name)
	 * @param type the type
	 * @return the type container name
	 */
	public static String getTypeContainerName(IType type) {
		IType outerType= type.getDeclaringType();
		if (outerType != null) {
			return outerType.getFullyQualifiedName('.');
		} else {
			return type.getPackageFragment().getElementName();
		}
	}

	
Concatenates two names. Uses a dot for separation.
Both strings can be empty or null.
Params:
name1 – the first name
name2 – the second name
Returns:
the concatenated name/**
	 * Concatenates two names. Uses a dot for separation.
	 * Both strings can be empty or <code>null</code>.
	 * @param name1 the first name
	 * @param name2 the second name
	 * @return the concatenated name
	 */
	public static String concatenateName(String name1, String name2) {
		StringBuilder buf= new StringBuilder();
		if (name1 != null && name1.length() > 0) {
			buf.append(name1);
		}
		if (name2 != null && name2.length() > 0) {
			if (buf.length() > 0) {
				buf.append('.');
			}
			buf.append(name2);
		}
		return buf.toString();
	}

	
Concatenates two names. Uses a dot for separation.
Both strings can be empty or null.
Params:
name1 – the first string
name2 – the second string
Returns:
the concatenated string/**
	 * Concatenates two names. Uses a dot for separation.
	 * Both strings can be empty or <code>null</code>.
	 * @param name1 the first string
	 * @param name2 the second string
	 * @return the concatenated string
	 */
	public static String concatenateName(char[] name1, char[] name2) {
		StringBuilder buf= new StringBuilder();
		if (name1 != null && name1.length > 0) {
			buf.append(name1);
		}
		if (name2 != null && name2.length > 0) {
			if (buf.length() > 0) {
				buf.append('.');
			}
			buf.append(name2);
		}
		return buf.toString();
	}

	
Returns whether the two names match. They match if they
are equal, or if they are the same name but one is missing a dot-separated qualifier.
Params:
nameA – a potentially qualified name
nameB – a potentially qualified name
Returns:
true iff the given names match
Since:
3.8/**
	 * Returns whether the two names match. They match if they
	 * are equal, or if they are the same name but one is missing a dot-separated qualifier.
	 * 
	 * @param nameA a potentially qualified name
	 * @param nameB a potentially qualified name
	 * @return <code>true</code> iff the given names match
	 * @since 3.8
	 */
	public static boolean isMatchingName(String nameA, String nameB) {
		int a= nameA.length();
		int b= nameB.length();
		if (a == b) {
			return nameA.equals(nameB);
		} else if (a < b - 1) {
			return nameB.endsWith(nameA) && nameB.charAt(b - a - 1) == '.';
		} else if (b < a - 1) {
			return nameA.endsWith(nameB) && nameA.charAt(a - b - 1) == '.';
		} else {
			return false;
		}
	}

	
Evaluates if a member (possible from another package) is visible from
elements in a package.
Params:
member – The member to test the visibility for
pack – The package in focus
Throws:
JavaModelException – thrown when the member can not be accessed
Returns:
returns true if the member is visible from the package/**
	 * Evaluates if a member (possible from another package) is visible from
	 * elements in a package.
	 * @param member The member to test the visibility for
	 * @param pack The package in focus
	 * @return returns <code>true</code> if the member is visible from the package
	 * @throws JavaModelException thrown when the member can not be accessed
	 */
	public static boolean isVisible(IMember member, IPackageFragment pack) throws JavaModelException {

		int type= member.getElementType();
		if  (type == IJavaElement.INITIALIZER ||  (type == IJavaElement.METHOD && member.getElementName().startsWith("<"))) { //$NON-NLS-1$
			return false;
		}

		int otherflags= member.getFlags();
		IType declaringType= member.getDeclaringType();
		if (Flags.isPublic(otherflags) || (declaringType != null && isInterfaceOrAnnotation(declaringType))) {
			return true;
		} else if (Flags.isPrivate(otherflags)) {
			return false;
		}

		IPackageFragment otherpack= (IPackageFragment) member.getAncestor(IJavaElement.PACKAGE_FRAGMENT);
		return (pack != null && otherpack != null && isSamePackage(pack, otherpack));
	}

	
Evaluates if a member in the focus' element hierarchy is visible from
elements in a package.
Params:
member – The member to test the visibility for
pack – The package of the focus element focus
Throws:
JavaModelException – thrown when the member can not be accessed
Returns:
returns true if the member is visible from the package/**
	 * Evaluates if a member in the focus' element hierarchy is visible from
	 * elements in a package.
	 * @param member The member to test the visibility for
	 * @param pack The package of the focus element focus
	 * @return returns <code>true</code> if the member is visible from the package
	 * @throws JavaModelException thrown when the member can not be accessed
	 */
	public static boolean isVisibleInHierarchy(IMember member, IPackageFragment pack) throws JavaModelException {
		int type= member.getElementType();
		if  (type == IJavaElement.INITIALIZER ||  (type == IJavaElement.METHOD && member.getElementName().startsWith("<"))) { //$NON-NLS-1$
			return false;
		}

		int otherflags= member.getFlags();

		IType declaringType= member.getDeclaringType();
		if (Flags.isPublic(otherflags) || Flags.isProtected(otherflags) || (declaringType != null && isInterfaceOrAnnotation(declaringType))) {
			return true;
		} else if (Flags.isPrivate(otherflags)) {
			return false;
		}

		IPackageFragment otherpack= (IPackageFragment) member.getAncestor(IJavaElement.PACKAGE_FRAGMENT);
		return (pack != null && pack.equals(otherpack));
	}


	
Returns the package fragment root of IJavaElement. If the given
element is already a package fragment root, the element itself is returned.
Params:
element – the element
Returns:
the package fragment root of the element or null/**
	 * Returns the package fragment root of <code>IJavaElement</code>. If the given
	 * element is already a package fragment root, the element itself is returned.
	 * @param element the element
	 * @return the package fragment root of the element or <code>null</code>
	 */
	public static IPackageFragmentRoot getPackageFragmentRoot(IJavaElement element) {
		return (IPackageFragmentRoot) element.getAncestor(IJavaElement.PACKAGE_FRAGMENT_ROOT);
	}

	
Finds a method in a type.
This searches for a method with the same name and signature. Parameter types are only
compared by the simple name, no resolving for the fully qualified type name is done.
Constructors are only compared by parameters, not the name.
Params:
name – The name of the method to find
paramTypes – The type signatures of the parameters e.g. {"QString;","I"}
isConstructor – If the method is a constructor
type – the type
Throws:
JavaModelException – thrown when the type can not be accessed
Returns:
The first found method or null, if nothing foun/**
	 * Finds a method in a type.
	 * This searches for a method with the same name and signature. Parameter types are only
	 * compared by the simple name, no resolving for the fully qualified type name is done.
	 * Constructors are only compared by parameters, not the name.
	 * @param name The name of the method to find
	 * @param paramTypes The type signatures of the parameters e.g. <code>{"QString;","I"}</code>
	 * @param isConstructor If the method is a constructor
	 * @param type the type
	 * @return The first found method or <code>null</code>, if nothing foun
	 * @throws JavaModelException thrown when the type can not be accessed
	 */
	public static IMethod findMethod(String name, String[] paramTypes, boolean isConstructor, IType type) throws JavaModelException {
		IMethod[] methods= type.getMethods();
		for (int i= 0; i < methods.length; i++) {
			if (isSameMethodSignature(name, paramTypes, isConstructor, methods[i])) {
				return methods[i];
			}
		}
		return null;
	}

	
Finds a method in a type and all its super types. The super class hierarchy is searched first, then the super interfaces. This searches for a method with the same name and signature. Parameter types are only compared by the simple name, no resolving for the fully qualified type name is done. Constructors are only compared by parameters, not the name. NOTE: For finding overridden methods or for finding the declaring method, use MethodOverrideTester 
Params:
hierarchy – The hierarchy containing the type
	@param type The type to start the search from
name – The name of the method to find
paramTypes – The type signatures of the parameters e.g. {"QString;","I"}
isConstructor – If the method is a constructor
Throws:
JavaModelException – thrown when the type can not be accessed
Returns:
The first found method or null, if nothing found/**
	 * Finds a method in a type and all its super types. The super class hierarchy is searched first, then the super interfaces.
	 * This searches for a method with the same name and signature. Parameter types are only
	 * compared by the simple name, no resolving for the fully qualified type name is done.
	 * Constructors are only compared by parameters, not the name.
	 * NOTE: For finding overridden methods or for finding the declaring method, use {@link MethodOverrideTester}
	 * @param hierarchy The hierarchy containing the type
	 * 	@param type The type to start the search from
	 * @param name The name of the method to find
	 * @param paramTypes The type signatures of the parameters e.g. <code>{"QString;","I"}</code>
	 * @param isConstructor If the method is a constructor
	 * @return The first found method or <code>null</code>, if nothing found
	 * @throws JavaModelException thrown when the type can not be accessed
	 */
	public static IMethod findMethodInHierarchy(ITypeHierarchy hierarchy, IType type, String name, String[] paramTypes, boolean isConstructor) throws JavaModelException {
		IMethod method= findMethod(name, paramTypes, isConstructor, type);
		if (method != null) {
			return method;
		}
		IType superClass= hierarchy.getSuperclass(type);
		if (superClass != null) {
			IMethod res=  findMethodInHierarchy(hierarchy, superClass, name, paramTypes, isConstructor);
			if (res != null) {
				return res;
			}
		}
		if (!isConstructor) {
			IType[] superInterfaces= hierarchy.getSuperInterfaces(type);
			for (int i= 0; i < superInterfaces.length; i++) {
				IMethod res= findMethodInHierarchy(hierarchy, superInterfaces[i], name, paramTypes, false);
				if (res != null) {
					return res;
				}
			}
		}
		return method;
	}


	
Tests if a method equals to the given signature.
Parameter types are only compared by the simple name, no resolving for
the fully qualified type name is done. Constructors are only compared by
parameters, not the name.
Params:
name – Name of the method
paramTypes – The type signatures of the parameters e.g. {"QString;","I"}
isConstructor – Specifies if the method is a constructor
curr – the method
Throws:
JavaModelException – thrown when the method can not be accessed
Returns:
Returns true if the method has the given name and parameter types and constructor state./**
	 * Tests if a method equals to the given signature.
	 * Parameter types are only compared by the simple name, no resolving for
	 * the fully qualified type name is done. Constructors are only compared by
	 * parameters, not the name.
	 * @param name Name of the method
	 * @param paramTypes The type signatures of the parameters e.g. <code>{"QString;","I"}</code>
	 * @param isConstructor Specifies if the method is a constructor
	 * @param curr the method
	 * @return Returns <code>true</code> if the method has the given name and parameter types and constructor state.
	 * @throws JavaModelException thrown when the method can not be accessed
	 */
	public static boolean isSameMethodSignature(String name, String[] paramTypes, boolean isConstructor, IMethod curr) throws JavaModelException {
		if (isConstructor || name.equals(curr.getElementName())) {
			if (isConstructor == curr.isConstructor()) {
				String[] currParamTypes= curr.getParameterTypes();
				if (paramTypes.length == currParamTypes.length) {
					for (int i= 0; i < paramTypes.length; i++) {
						String t1= Signature.getSimpleName(Signature.toString(paramTypes[i]));
						String t2= Signature.getSimpleName(Signature.toString(currParamTypes[i]));
						if (!t1.equals(t2)) {
							return false;
						}
					}
					return true;
				}
			}
		}
		return false;
	}

	
Tests if two IPackageFragments represent the same logical java package.
Params:
pack1 – the first package
pack2 – the second package
Returns:
true if the package fragments' names are equal./**
	 * Tests if two <code>IPackageFragment</code>s represent the same logical java package.
	 * @param pack1 the first package
	 * @param pack2 the second package
	 * @return <code>true</code> if the package fragments' names are equal.
	 */
	public static boolean isSamePackage(IPackageFragment pack1, IPackageFragment pack2) {
		return pack1.getElementName().equals(pack2.getElementName());
	}

	
Checks whether the given type has a valid main method or not.
Params:
type – the type to test
Throws:
JavaModelException – thrown when the type can not be accessed
Returns:
returns true if the type has a main method/**
	 * Checks whether the given type has a valid main method or not.
	 * @param type the type to test
	 * @return returns <code>true</code> if the type has a main method
	 * @throws JavaModelException thrown when the type can not be accessed
	 */
	public static boolean hasMainMethod(IType type) throws JavaModelException {
		IMethod[] methods= type.getMethods();
		for (int i= 0; i < methods.length; i++) {
			if (methods[i].isMainMethod()) {
				return true;
			}
		}
		return false;
	}

	
Checks if the field is boolean.
Params:
field – the field
Throws:
JavaModelException – thrown when the field can not be accessed
Returns:
returns true if the field returns a boolean/**
	 * Checks if the field is boolean.
	 * @param field the field
	 * @return returns <code>true</code> if the field returns a boolean
	 * @throws JavaModelException thrown when the field can not be accessed
	 */
	public static boolean isBoolean(IField field) throws JavaModelException{
		return field.getTypeSignature().equals(Signature.SIG_BOOLEAN);
	}

	
Params:
type – the type to test
Throws:
JavaModelException – thrown when the field can not be accessed
Returns:
true iff the type is an interface or an annotation/**
	 * @param type the type to test
	 * @return <code>true</code> iff the type is an interface or an annotation
	 * @throws JavaModelException thrown when the field can not be accessed
	 */
	public static boolean isInterfaceOrAnnotation(IType type) throws JavaModelException {
		return type.isInterface();
	}

	
Resolves a type name in the context of the declaring type.
Params:
refTypeSig – the type name in signature notation (for example 'QVector') this can also be an array type, but dimensions will be ignored.
declaringType – the context for resolving (type where the reference was made in)
Throws:
JavaModelException – thrown when the type can not be accessed
Returns:
returns the fully qualified type name or build-in-type name. if a unresolved type couldn't be resolved null is returned/**
	 * Resolves a type name in the context of the declaring type.
	 *
	 * @param refTypeSig the type name in signature notation (for example 'QVector') this can also be an array type, but dimensions will be ignored.
	 * @param declaringType the context for resolving (type where the reference was made in)
	 * @return returns the fully qualified type name or build-in-type name. if a unresolved type couldn't be resolved null is returned
	 * @throws JavaModelException thrown when the type can not be accessed
	 */
	public static String getResolvedTypeName(String refTypeSig, IType declaringType) throws JavaModelException {
		return getResolvedTypeName(refTypeSig, declaringType, '.');
	}

	
Resolves a type name in the context of the declaring type.
Params:
refTypeSig – the type name in signature notation (for example 'QVector') this can also be an array type, but dimensions will be ignored.
declaringType – the context for resolving (type where the reference was made in)
enclosingTypeSeparator – the enclosing type separator used in the qualified type name
Throws:
JavaModelException – thrown when the type can not be accessed
Returns:
returns the fully qualified type name or build-in-type name. if a unresolved type couldn't be resolved null is returned/**
	 * Resolves a type name in the context of the declaring type.
	 *
	 * @param refTypeSig the type name in signature notation (for example 'QVector') this can also be an array type, but dimensions will be ignored.
	 * @param declaringType the context for resolving (type where the reference was made in)
	 * @param enclosingTypeSeparator the enclosing type separator used in the qualified type name 
	 * @return returns the fully qualified type name or build-in-type name. if a unresolved type couldn't be resolved null is returned
	 * @throws JavaModelException thrown when the type can not be accessed
	 */
	public static String getResolvedTypeName(String refTypeSig, IType declaringType, char enclosingTypeSeparator) throws JavaModelException {
		int arrayCount= Signature.getArrayCount(refTypeSig);
		char type= refTypeSig.charAt(arrayCount);
		if (type == Signature.C_UNRESOLVED) {
			String name= ""; //$NON-NLS-1$
			int bracket= refTypeSig.indexOf(Signature.C_GENERIC_START, arrayCount + 1);
			if (bracket > 0)
				name= refTypeSig.substring(arrayCount + 1, bracket);
			else {
				int semi= refTypeSig.indexOf(Signature.C_SEMICOLON, arrayCount + 1);
				if (semi == -1) {
					throw new IllegalArgumentException();
				}
				name= refTypeSig.substring(arrayCount + 1, semi);
			}
			String[][] resolvedNames= declaringType.resolveType(name);
			if (resolvedNames != null && resolvedNames.length > 0) {
				return JavaModelUtil.concatenateName(resolvedNames[0][0], resolvedNames[0][1].replace('.', enclosingTypeSeparator));
			}
			return null;
		} else {
			return Signature.toString(refTypeSig.substring(arrayCount));
		}
	}

	
Returns if a CU can be edited.
Params:
cu – the compilation unit
Returns:
true if the CU can be edited/**
	 * Returns if a CU can be edited.
	 * @param cu the compilation unit
	 * @return <code>true</code> if the CU can be edited
	 */
	public static boolean isEditable(ICompilationUnit cu)  {
		Assert.isNotNull(cu);
		IResource resource= cu.getPrimary().getResource();
		return (resource.exists() && !resource.getResourceAttributes().isReadOnly());
	}

	
Returns true if a cu is a primary cu (original or shared working copy)
Params:
cu – the compilation unit
Returns:
return true if the CU is primary/**
	 * Returns true if a cu is a primary cu (original or shared working copy)
	 * @param cu the compilation unit
	 * @return return <code>true</code> if the CU is primary
	 */
	public static boolean isPrimary(ICompilationUnit cu) {
		return cu.getOwner() == null;
	}

	
Checks whether the given type signature is from a primitive type.
Params:
typeSignature – the type signature string to check
Throws:
JavaModelException – if this element does not exist or if an exception occurs while
            accessing its corresponding resource.
Returns:
true if the type is a primitive type,  false otherwise
Since:
3.7/**
	 * Checks whether the given type signature is from a primitive type.
	 * 
	 * @param typeSignature the type signature string to check
	 * @return <code>true</code> if the type is a primitive type, <code> false</code> otherwise
	 * @throws JavaModelException if this element does not exist or if an exception occurs while
	 *             accessing its corresponding resource.
	 * @since 3.7
	 */
	public static boolean isPrimitive(String typeSignature) throws JavaModelException {
		return Signature.getTypeSignatureKind(Signature.getElementType(typeSignature)) == Signature.BASE_TYPE_SIGNATURE;
	}

	/*
     * Don't log not-exists exceptions
     *
     * Also see bug http://bugs.eclipse.org/bugs/show_bug.cgi?id=19253.
     * Since 3.4 we also don't log non-exists exception in non-working copies.
	 */
	public static boolean isExceptionToBeLogged(CoreException exception) {
		if (!(exception instanceof JavaModelException))
			return true;
		JavaModelException je= (JavaModelException)exception;
		if (!je.isDoesNotExist())
			return true;
		return false;
	}

	public static IType[] getAllSuperTypes(IType type, IProgressMonitor pm) throws JavaModelException {
		try {
			// workaround for 23656
			IType[] superTypes= SuperTypeHierarchyCache.getTypeHierarchy(type).getAllSupertypes(type);
			if (type.isInterface()) {
				IType objekt= type.getJavaProject().findType("java.lang.Object");//$NON-NLS-1$
				if (objekt != null) {
					IType[] superInterfacesAndObject= new IType[superTypes.length + 1];
					System.arraycopy(superTypes, 0, superInterfacesAndObject, 0, superTypes.length);
					superInterfacesAndObject[superTypes.length]= objekt;
					return superInterfacesAndObject;
				}
			}
			return superTypes;
		} finally {
			if (pm != null)
				pm.done();
		}
	}

	public static boolean isSuperType(ITypeHierarchy hierarchy, IType possibleSuperType, IType type) {
		// filed bug 112635 to add this method to ITypeHierarchy
		IType superClass= hierarchy.getSuperclass(type);
		if (superClass != null && (possibleSuperType.equals(superClass) || isSuperType(hierarchy, possibleSuperType, superClass))) {
			return true;
		}
		if (Flags.isInterface(hierarchy.getCachedFlags(possibleSuperType))) {
			IType[] superInterfaces= hierarchy.getSuperInterfaces(type);
			for (int i= 0; i < superInterfaces.length; i++) {
				IType curr= superInterfaces[i];
				if (possibleSuperType.equals(curr) || isSuperType(hierarchy, possibleSuperType, curr)) {
					return true;
				}
			}
		}
		return false;
	}

	public static boolean isExcludedPath(IPath resourcePath, IPath[] exclusionPatterns) {
		char[] path = resourcePath.toString().toCharArray();
		for (int i = 0, length = exclusionPatterns.length; i < length; i++) {
			char[] pattern= exclusionPatterns[i].toString().toCharArray();
			if (CharOperation.pathMatch(pattern, path, true, '/')) {
				return true;
			}
		}
		return false;
	}


	
Returns whether the given resource path matches one of the exclusion
patterns.
Params:
resourcePath – the resource path
exclusionPatterns – the exclusion patterns
See Also:
IClasspathEntry.getExclusionPatterns
Returns:
returns  true if the given resource path matches one of the exclusion/**
	 * Returns whether the given resource path matches one of the exclusion
	 * patterns.
	 * @param resourcePath the resource path
	 * @param exclusionPatterns the exclusion patterns
	 * @return returns <code> true</code> if the given resource path matches one of the exclusion
	 *
	 * @see IClasspathEntry#getExclusionPatterns
	 */
	public static boolean isExcluded(IPath resourcePath, char[][] exclusionPatterns) {
		if (exclusionPatterns == null) return false;
		char[] path = resourcePath.toString().toCharArray();
		for (int i = 0, length = exclusionPatterns.length; i < length; i++)
			if (CharOperation.pathMatch(exclusionPatterns[i], path, true, '/'))
				return true;
		return false;
	}


	
Force a reconcile of a compilation unit.
Params:
unit – the compilation unit
Throws:
JavaModelException – thrown when the compilation unit can not be accessed/**
	 * Force a reconcile of a compilation unit.
	 * @param unit the compilation unit
	 * @throws JavaModelException thrown when the compilation unit can not be accessed
	 */
	public static void reconcile(ICompilationUnit unit) throws JavaModelException {
		unit.reconcile(
				ICompilationUnit.NO_AST,
				false /* don't force problem detection */,
				null /* use primary owner */,
				null /* no progress monitor */);
	}

	
Helper method that tests if an classpath entry can be found in a
container. null is returned if the entry can not be found
or if the container does not allows the configuration of source
attachments
Params:
jproject – The container's parent project
containerPath – The path of the container
libPath – The path of the library to be found
Throws:
JavaModelException – thrown if accessing the container failed
Returns:
IClasspathEntry A classpath entry from the container of
null if the container can not be modified./**
	 * Helper method that tests if an classpath entry can be found in a
	 * container. <code>null</code> is returned if the entry can not be found
	 * or if the container does not allows the configuration of source
	 * attachments
	 * @param jproject The container's parent project
	 * @param containerPath The path of the container
	 * @param libPath The path of the library to be found
	 * @return IClasspathEntry A classpath entry from the container of
	 * <code>null</code> if the container can not be modified.
	 * @throws JavaModelException thrown if accessing the container failed
	 */
	public static IClasspathEntry getClasspathEntryToEdit(IJavaProject jproject, IPath containerPath, IPath libPath) throws JavaModelException {
		IClasspathContainer container= JavaCore.getClasspathContainer(containerPath, jproject);
		ClasspathContainerInitializer initializer= JavaCore.getClasspathContainerInitializer(containerPath.segment(0));
		if (container != null && initializer != null && initializer.canUpdateClasspathContainer(containerPath, jproject)) {
			return findEntryInContainer(container, libPath);
		}
		return null; // attachment not possible
	}

	
Finds an entry in a container. null is returned if the entry can not be found
Params:
container – The container
libPath – The path of the library to be found
Returns:
IClasspathEntry A classpath entry from the container of
null if the container can not be modified./**
	 * Finds an entry in a container. <code>null</code> is returned if the entry can not be found
	 * @param container The container
	 * @param libPath The path of the library to be found
	 * @return IClasspathEntry A classpath entry from the container of
	 * <code>null</code> if the container can not be modified.
	 */
	public static IClasspathEntry findEntryInContainer(IClasspathContainer container, IPath libPath) {
		IClasspathEntry[] entries= container.getClasspathEntries();
		for (int i= 0; i < entries.length; i++) {
			IClasspathEntry curr= entries[i];
			IClasspathEntry resolved= JavaCore.getResolvedClasspathEntry(curr);
			if (resolved != null && libPath.equals(resolved.getPath())) {
				return curr; // return the real entry
			}
		}
		return null; // attachment not possible
	}

	
Returns the classpath entry of the given package fragment root. This is the raw entry, except
if the root is a referenced library, in which case it's the resolved entry.
Params:
root – a package fragment root
Throws:
JavaModelException – if accessing the entry failed
Returns:
the corresponding classpath entry
Since:
3.6/**
	 * Returns the classpath entry of the given package fragment root. This is the raw entry, except
	 * if the root is a referenced library, in which case it's the resolved entry.
	 * 
	 * @param root a package fragment root
	 * @return the corresponding classpath entry
	 * @throws JavaModelException if accessing the entry failed
	 * @since 3.6
	 */
	public static IClasspathEntry getClasspathEntry(IPackageFragmentRoot root) throws JavaModelException {
		IClasspathEntry rawEntry= root.getRawClasspathEntry();
		int rawEntryKind= rawEntry.getEntryKind();
		switch (rawEntryKind) {
			case IClasspathEntry.CPE_LIBRARY:
			case IClasspathEntry.CPE_VARIABLE:
			case IClasspathEntry.CPE_CONTAINER: // should not happen, see https://bugs.eclipse.org/bugs/show_bug.cgi?id=305037
				if (root.isArchive() && root.getKind() == IPackageFragmentRoot.K_BINARY) {
					IClasspathEntry resolvedEntry= root.getResolvedClasspathEntry();
					if (resolvedEntry.getReferencingEntry() != null)
						return resolvedEntry;
					else
						return rawEntry;
				}
		}
		return rawEntry;
	}

	
Get all compilation units of a selection.
Params:
javaElements – the selected java elements
Throws:
JavaModelException – if this element does not exist or if an exception occurs while
            accessing its corresponding resource
Returns:
all compilation units containing and contained in elements from javaElements/**
	 * Get all compilation units of a selection.
	 *
	 * @param javaElements the selected java elements
	 * @return all compilation units containing and contained in elements from javaElements
	 * @throws JavaModelException if this element does not exist or if an exception occurs while
	 *             accessing its corresponding resource
	 */
	public static ICompilationUnit[] getAllCompilationUnits(IJavaElement[] javaElements) throws JavaModelException {
		HashSet<ICompilationUnit> result= new HashSet<>();
		for (int i= 0; i < javaElements.length; i++) {
			addAllCus(result, javaElements[i]);
		}
		return result.toArray(new ICompilationUnit[result.size()]);
	}

	private static void addAllCus(HashSet<ICompilationUnit> collector, IJavaElement javaElement) throws JavaModelException {
		switch (javaElement.getElementType()) {
			case IJavaElement.JAVA_PROJECT:
				IJavaProject javaProject= (IJavaProject) javaElement;
				IPackageFragmentRoot[] packageFragmentRoots= javaProject.getPackageFragmentRoots();
				for (int i= 0; i < packageFragmentRoots.length; i++)
					addAllCus(collector, packageFragmentRoots[i]);
				return;

			case IJavaElement.PACKAGE_FRAGMENT_ROOT:
				IPackageFragmentRoot packageFragmentRoot= (IPackageFragmentRoot) javaElement;
				if (packageFragmentRoot.getKind() != IPackageFragmentRoot.K_SOURCE)
					return;
				IJavaElement[] packageFragments= packageFragmentRoot.getChildren();
				for (int j= 0; j < packageFragments.length; j++)
					addAllCus(collector, packageFragments[j]);
				return;

			case IJavaElement.PACKAGE_FRAGMENT:
				IPackageFragment packageFragment= (IPackageFragment) javaElement;
				collector.addAll(Arrays.asList(packageFragment.getCompilationUnits()));
				return;

			case IJavaElement.COMPILATION_UNIT:
				collector.add((ICompilationUnit) javaElement);
				return;

			default:
				IJavaElement cu= javaElement.getAncestor(IJavaElement.COMPILATION_UNIT);
				if (cu != null)
					collector.add((ICompilationUnit) cu);
		}
	}


	public static void setComplianceOptions(Map<String, String> map, String compliance) {
		JavaCore.setComplianceOptions(compliance, map);
	}

	public static void setDefaultClassfileOptions(Map<String, String> map, String compliance) {
		map.put(JavaCore.COMPILER_CODEGEN_INLINE_JSR_BYTECODE, is50OrHigher(compliance) ? JavaCore.ENABLED : JavaCore.DISABLED);
		map.put(JavaCore.COMPILER_LOCAL_VARIABLE_ATTR, JavaCore.GENERATE);
		map.put(JavaCore.COMPILER_LINE_NUMBER_ATTR, JavaCore.GENERATE);
		map.put(JavaCore.COMPILER_SOURCE_FILE_ATTR, JavaCore.GENERATE);
		map.put(JavaCore.COMPILER_CODEGEN_UNUSED_LOCAL, JavaCore.PRESERVE);
	}

	
Params:
version1 – the first version
version2 – the second version
Returns:
true iff version1 is less than version2/**
	 * @param version1 the first version
	 * @param version2 the second version
	 * @return <code>true</code> iff version1 is less than version2
	 */
	public static boolean isVersionLessThan(String version1, String version2) {
		return JavaCore.compareJavaVersions(version1, version2) < 0;
	}


	public static boolean is50OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_1_5);
	}
	
	public static boolean is16OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_1_6);
	}
	
	public static boolean is17OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_1_7);
	}

	public static boolean is18OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_1_8);
	}

	public static boolean is9OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_9);
	}
	
	public static boolean is10OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_10);
	}

	public static boolean is11OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_11);
	}

	public static boolean is12OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_12);
	}

	public static boolean is13OrHigher(String compliance) {
		return !isVersionLessThan(compliance, JavaCore.VERSION_13);
	}

	
Checks if the given project or workspace has source compliance 1.5 or greater.
Params:
project – the project to test or null to test the workspace settings
Returns:
true if the given project or workspace has source compliance 1.5 or greater./**
	 * Checks if the given project or workspace has source compliance 1.5 or greater.
	 *
	 * @param project the project to test or <code>null</code> to test the workspace settings
	 * @return <code>true</code> if the given project or workspace has source compliance 1.5 or greater.
	 */
	public static boolean is50OrHigher(IJavaProject project) {
		return is50OrHigher(getSourceCompliance(project));
	}

	
Checks if the given project or workspace has source compliance 1.7 or greater.
Params:
project – the project to test or null to test the workspace settings
Returns:
true if the given project or workspace has source compliance 1.7 or greater./**
	 * Checks if the given project or workspace has source compliance 1.7 or greater.
	 *
	 * @param project the project to test or <code>null</code> to test the workspace settings
	 * @return <code>true</code> if the given project or workspace has source compliance 1.7 or greater.
	 */
	public static boolean is17OrHigher(IJavaProject project) {
		return is17OrHigher(getSourceCompliance(project));
	}
	
	
Checks if the given project or workspace has source compliance 1.8 or greater.
Params:
project – the project to test or null to test the workspace settings
Returns:
true if the given project or workspace has source compliance 1.8 or
        greater./**
	 * Checks if the given project or workspace has source compliance 1.8 or greater.
	 * 
	 * @param project the project to test or <code>null</code> to test the workspace settings
	 * @return <code>true</code> if the given project or workspace has source compliance 1.8 or
	 *         greater.
	 */
	public static boolean is18OrHigher(IJavaProject project) {
		return is18OrHigher(getSourceCompliance(project));
	}

	
Checks if the given project or workspace has source compliance 9 or greater.
Params:
project – the project to test or null to test the workspace settings
Returns:
true if the given project or workspace has source compliance 9 or
        greater./**
	 * Checks if the given project or workspace has source compliance 9 or greater.
	 * 
	 * @param project the project to test or <code>null</code> to test the workspace settings
	 * @return <code>true</code> if the given project or workspace has source compliance 9 or
	 *         greater.
	 */
	public static boolean is9OrHigher(IJavaProject project) {
		return is9OrHigher(getSourceCompliance(project));
	}

	
Checks if the given project or workspace has source compliance 10 or greater.
Params:
project – the project to test or null to test the workspace settings
Returns:
true if the given project or workspace has source compliance 10 or greater./**
	 * Checks if the given project or workspace has source compliance 10 or greater.
	 * 
	 * @param project the project to test or <code>null</code> to test the workspace settings
	 * @return <code>true</code> if the given project or workspace has source compliance 10 or greater.
	 */
	public static boolean is10OrHigher(IJavaProject project) {
		return is10OrHigher(getSourceCompliance(project));
	}

	
Checks if the given project or workspace has source compliance 11 or greater.
Params:
project – the project to test or null to test the workspace settings
Returns:
true if the given project or workspace has source compliance 11 or greater./**
	 * Checks if the given project or workspace has source compliance 11 or greater.
	 * 
	 * @param project the project to test or <code>null</code> to test the workspace settings
	 * @return <code>true</code> if the given project or workspace has source compliance 11 or greater.
	 */
	public static boolean is11OrHigher(IJavaProject project) {
		return is11OrHigher(getSourceCompliance(project));
	}
	
	public static boolean is12OrHigher(IJavaProject project) {
		return is12OrHigher(getSourceCompliance(project));
	}

	
Checks if the given project or workspace has source compliance 13 or greater.
Params:
project – the project to test or null to test the workspace settings
Returns:
true if the given project or workspace has source compliance 13 or greater./**
	 * Checks if the given project or workspace has source compliance 13 or greater.
	 * 
	 * @param project the project to test or <code>null</code> to test the workspace settings
	 * @return <code>true</code> if the given project or workspace has source compliance 13 or greater.
	 */
	public static boolean is13OrHigher(IJavaProject project) {
		return is13OrHigher(getSourceCompliance(project));
	}

	private static String getSourceCompliance(IJavaProject project) {
		return project != null ? project.getOption(JavaCore.COMPILER_SOURCE, true) : JavaCore.getOption(JavaCore.COMPILER_SOURCE);
	}
	
	
Checks if the JRE of the given project or workspace default JRE have source compliance 1.5 or
greater.
Params:
project – the project to test or null to test the workspace JRE
Throws:
CoreException – if unable to determine the project's VM install
Returns:
true if the JRE of the given project or workspace default JRE have
        source compliance 1.5 or greater./**
	 * Checks if the JRE of the given project or workspace default JRE have source compliance 1.5 or
	 * greater.
	 *
	 * @param project the project to test or <code>null</code> to test the workspace JRE
	 * @return <code>true</code> if the JRE of the given project or workspace default JRE have
	 *         source compliance 1.5 or greater.
	 * @throws CoreException if unable to determine the project's VM install
	 */
	public static boolean is50OrHigherJRE(IJavaProject project) throws CoreException {
		IVMInstall vmInstall;
		if (project == null) {
			vmInstall= JavaRuntime.getDefaultVMInstall();
		} else {
			vmInstall= JavaRuntime.getVMInstall(project);
		}
		if (!(vmInstall instanceof IVMInstall2))
			return true; // assume 1.5.

		String compliance= getCompilerCompliance((IVMInstall2) vmInstall, null);
		if (compliance == null)
			return true; // assume 1.5
		return is50OrHigher(compliance);
	}

	public static String getCompilerCompliance(IVMInstall2 vMInstall, String defaultCompliance) {
		String version= vMInstall.getJavaVersion();
		if (version == null) {
			return defaultCompliance;
		} else if (version.startsWith(JavaCore.VERSION_13)) {
			return JavaCore.VERSION_13;
		} else if (version.startsWith(JavaCore.VERSION_12)) {
			return JavaCore.VERSION_12;
		} else if (version.startsWith(JavaCore.VERSION_11)) {
			return JavaCore.VERSION_11;
		} else if (version.startsWith(JavaCore.VERSION_10)) {
			return JavaCore.VERSION_10;
		} else if (version.startsWith(JavaCore.VERSION_9)) {
			return JavaCore.VERSION_9;
		} else if (version.startsWith(JavaCore.VERSION_1_8)) {
			return JavaCore.VERSION_1_8;
		} else if (version.startsWith(JavaCore.VERSION_1_7)) {
			return JavaCore.VERSION_1_7;
		} else if (version.startsWith(JavaCore.VERSION_1_6)) {
			return JavaCore.VERSION_1_6;
		} else if (version.startsWith(JavaCore.VERSION_1_5)) {
			return JavaCore.VERSION_1_5;
		} else if (version.startsWith(JavaCore.VERSION_1_4)) {
			return JavaCore.VERSION_1_4;
		} else if (version.startsWith(JavaCore.VERSION_1_3)) {
			return JavaCore.VERSION_1_3;
		} else if (version.startsWith(JavaCore.VERSION_1_2)) {
			return JavaCore.VERSION_1_3;
		} else if (version.startsWith(JavaCore.VERSION_1_1)) {
			return JavaCore.VERSION_1_3;
		}
		return JavaCore.isSupportedJavaVersion(version) ? defaultCompliance : JavaModelUtil.VERSION_LATEST;
	}

	public static String getExecutionEnvironmentCompliance(IExecutionEnvironment executionEnvironment) {
		Map<String, String> complianceOptions= executionEnvironment.getComplianceOptions();
		if (complianceOptions != null) {
			Object compliance= complianceOptions.get(JavaCore.COMPILER_COMPLIANCE);
			if (compliance instanceof String)
				return (String)compliance;
		}
		
		// fallback:
		String desc= executionEnvironment.getId();
		if (desc.indexOf(JavaCore.VERSION_13) != -1) {
			return JavaCore.VERSION_13;
		} else if (desc.indexOf(JavaCore.VERSION_12) != -1) {
			return JavaCore.VERSION_12;
		} else if (desc.indexOf(JavaCore.VERSION_11) != -1) {
			return JavaCore.VERSION_11;
		} else if (desc.indexOf(JavaCore.VERSION_10) != -1) {
			return JavaCore.VERSION_10;
		} else if (desc.indexOf(JavaCore.VERSION_9) != -1) {
			return JavaCore.VERSION_9;
		} else if (desc.indexOf(JavaCore.VERSION_1_8) != -1) {
			return JavaCore.VERSION_1_8;
		} else if (desc.indexOf(JavaCore.VERSION_1_7) != -1) {
			return JavaCore.VERSION_1_7;
		} else if (desc.indexOf(JavaCore.VERSION_1_6) != -1) {
			return JavaCore.VERSION_1_6;
		} else if (desc.indexOf(JavaCore.VERSION_1_5) != -1) {
			return JavaCore.VERSION_1_5;
		} else if (desc.indexOf(JavaCore.VERSION_1_4) != -1) {
			return JavaCore.VERSION_1_4;
		}
		return JavaCore.VERSION_1_3;
	}

	
Compute a new name for a compilation unit, given the name of the new main type.
This query tries to maintain the existing extension (e.g. ".java").
Params:
cu – a compilation unit
newMainName – the new name of the cu's main type (without extension)
Returns:
the new name for the compilation unit/**
	 * Compute a new name for a compilation unit, given the name of the new main type.
	 * This query tries to maintain the existing extension (e.g. ".java").
	 *
	 * @param cu a compilation unit
	 * @param newMainName the new name of the cu's main type (without extension)
	 * @return the new name for the compilation unit
	 */
	public static String getRenamedCUName(ICompilationUnit cu, String newMainName) {
		String oldName = cu.getElementName();
		int i = oldName.lastIndexOf('.');
		if (i != -1) {
			return newMainName + oldName.substring(i);
		} else {
			return newMainName;
		}
	}

	public static boolean isImplicitImport(String qualifier, ICompilationUnit cu) {
		if ("java.lang".equals(qualifier)) {  //$NON-NLS-1$
			return true;
		}
		String packageName= cu.getParent().getElementName();
		if (qualifier.equals(packageName)) {
			return true;
		}
		String typeName= JavaCore.removeJavaLikeExtension(cu.getElementName());
		String mainTypeName= JavaModelUtil.concatenateName(packageName, typeName);
		return qualifier.equals(mainTypeName);
	}

	public static boolean isOpenableStorage(Object storage) {
		if (storage instanceof IJarEntryResource) {
			return ((IJarEntryResource) storage).isFile();
		} else {
			return storage instanceof IStorage;
		}
	}

	
Tells whether the given CU is the package-info.java.
Params:
cu – the compilation unit to test
Returns:
true if the given CU is the package-info.java
Since:
3.4/**
	 * Tells whether the given CU is the package-info.java.
	 *
	 * @param cu the compilation unit to test
	 * @return <code>true</code> if the given CU is the package-info.java
	 * @since 3.4
	 */
	public static boolean isPackageInfo(ICompilationUnit cu) {
		return PACKAGE_INFO_JAVA.equals(cu.getElementName());
	}

	
Tells whether the given CU is the module-info.java.
Params:
cu – the compilation unit to test
Returns:
true if the given CU is the module-info.java
Since:
3.14/**
	 * Tells whether the given CU is the module-info.java.
	 *
	 * @param cu the compilation unit to test
	 * @return <code>true</code> if the given CU is the module-info.java
	 * @since 3.14
	 */
	public static boolean isModuleInfo(ICompilationUnit cu) {
		return MODULE_INFO_JAVA.equals(cu.getElementName());
	}

	
Tells whether the given type root represents a module.
Params:
typeRoot – the type root to test
Returns:
true if the given type root is a module-info.java CU or a module-info.class class file.
Since:
3.14/**
	 * Tells whether the given type root represents a module.
	 * 
	 * @param typeRoot the type root to test
	 * @return <code>true</code> if the given type root is a module-info.java CU or a module-info.class class file.
	 * @since 3.14
	 */
	public static boolean isModuleInfo(ITypeRoot typeRoot) {
		return (typeRoot instanceof ICompilationUnit && isModuleInfo((ICompilationUnit) typeRoot))
				|| typeRoot instanceof IModularClassFile;
	}

	
Tells whether the given Java element represents a module.
Params:
javaElement – the Java element to test
Returns:
true if the given Java element represents a module.
Since:
3.14/**
	 * Tells whether the given Java element represents a module.
	 * 
	 * @param javaElement the Java element to test
	 * @return <code>true</code> if the given Java element represents a module.
	 * @since 3.14
	 */
	public static boolean isModule(IJavaElement javaElement) {
		return javaElement instanceof IModuleDescription
				|| javaElement instanceof ITypeRoot && isModuleInfo((ITypeRoot) javaElement);
	}

	
Tells whether the given package fragment contains any ordinary compilation unit,
not counting the modular compilation unit module-info.java nor its class file module-info.class.
Params:
fragment – a package fragment to test
Throws:
JavaModelException – if the package fragment does not exist or if an
     exception occurs while accessing its corresponding resource
Returns:
true iff at least one ordinary compilation unit (or class file) was found.
Since:
3.14/**
	 * Tells whether the given package fragment contains any ordinary compilation unit,
	 * not counting the modular compilation unit module-info.java nor its class file module-info.class.
	 * @param fragment a package fragment to test
	 * @return true iff at least one ordinary compilation unit (or class file) was found. 
	 * @throws JavaModelException if the package fragment does not exist or if an
	 *      exception occurs while accessing its corresponding resource
	 * @since 3.14
	 */
	public static boolean containsOrdinaryCompilationUnit(IPackageFragment fragment) throws JavaModelException {
		for (IJavaElement child : fragment.getChildren()) {
			if (child instanceof ITypeRoot && !isModuleInfo((ITypeRoot) child))
				return true;
		}
		return false;
	}

	public static boolean isPolymorphicSignature(IMethod method) {
		return method.getAnnotation("java.lang.invoke.MethodHandle$PolymorphicSignature").exists(); //$NON-NLS-1$
	}

	
Applies a text edit to a compilation unit.
Params:
cu – the compilation unit to apply the edit to
edit – the edit to apply
save – is set, save the CU after the edit has been applied
monitor – the progress monitor to use
Throws:
CoreException – Thrown when the access to the CU failed
ValidateEditException – if validate edit fails/**
	 * Applies a text edit to a compilation unit.
	 * 
	 * @param cu the compilation unit to apply the edit to
	 * @param edit the edit to apply
	 * @param save is set, save the CU after the edit has been applied
	 * @param monitor the progress monitor to use
	 * @throws CoreException Thrown when the access to the CU failed
	 * @throws ValidateEditException if validate edit fails
	 */
	public static void applyEdit(ICompilationUnit cu, TextEdit edit, boolean save, IProgressMonitor monitor) throws CoreException, ValidateEditException {
		SubMonitor subMonitor= SubMonitor.convert(monitor, JavaManipulationMessages.JavaModelUtil_applyedit_operation, 2);
		IFile file= (IFile) cu.getResource();
		if (!save || !file.exists()) {
			cu.applyTextEdit(edit, subMonitor.split(2));
		} else {
			IStatus status= Resources.makeCommittable(new IResource [] {file}, null);
			if (!status.isOK()) {
				throw new ValidateEditException(status);
			}
			cu.applyTextEdit(edit, subMonitor.split(1));
			cu.save(subMonitor.split(1), true);
		}
	}
}