Copyright (c) 2016, 2018 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
/*******************************************************************************
 * Copyright (c) 2016, 2018 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
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.env;

import org.eclipse.jdt.core.compiler.CharOperation;

Represents an entry on the module path of a project. Could be a single module or a collection of
modules (like a jimage or an exploded module directory structure)
/**
 * Represents an entry on the module path of a project. Could be a single module or a collection of
 * modules (like a jimage or an exploded module directory structure)
 *
 */
public interface IModulePathEntry {

	
Get the module that this entry contributes. May be null, for instance when this entry does not
represent a single module
Returns:
The module that this entry contributes or null/**
	 * Get the module that this entry contributes. May be null, for instance when this entry does not
	 * represent a single module
	 * 
	 * @return The module that this entry contributes or null
	 */
	default IModule getModule() {
		return null;
	}
	
	
Get the module named name from this entry. May be null
Params:
name – - The name of the module to look up
Returns:
The module named name or null/**
	 * Get the module named name from this entry. May be null
	 * 
	 * @param name - The name of the module to look up
	 * 
	 * @return The module named name or null
	 */
	default IModule getModule(char[] name) {
		IModule mod = getModule();
		if (mod != null && CharOperation.equals(name, mod.name()))
			return mod;
		return null;
	}

	
Indicates whether this entry knows the module named name and can answer queries regarding the module
Params:
name – The name of the module
Returns:
True if this entry knows the module, false otherwise/**
	 * Indicates whether this entry knows the module named name and can answer queries regarding the module
	 * 
	 * @param name The name of the module
	 * 
	 * @return True if this entry knows the module, false otherwise
	 */
	default boolean servesModule(char[] name) {
		return getModule(name) != null;
	}

	
Answer the relevant modules that declare the given package.
If moduleName is ModuleBinding.ANY then all packages are relevant,
if moduleName is ModuleBinding.UNNAMED, then only packages in the unnamed module are relevant,
otherwise consider only packages in the module identified by moduleName.
/**
	 * Answer the relevant modules that declare the given package.
	 * If moduleName is ModuleBinding.ANY then all packages are relevant,
	 * if moduleName is ModuleBinding.UNNAMED, then only packages in the unnamed module are relevant,
	 * otherwise consider only packages in the module identified by moduleName.
	 */
	char[][] getModulesDeclaringPackage(String qualifiedPackageName, /*@Nullable*/String moduleName);

	
Answer whether the given package has any compilation unit (.java or .class) in the given module.
For entries representing a single module, the module name should be checked before invoking this method.
Params:
qualifiedPackageName – '/'-separated package name
moduleName – if non-null only CUs attached to the given module should be considered
Returns:
true iff a .java or .class file could be found in the given module / package./**
	 * Answer whether the given package has any compilation unit (.java or .class) in the given module.
	 * For entries representing a single module, the module name should be checked before invoking this method.
	 * @param qualifiedPackageName '/'-separated package name
	 * @param moduleName if non-null only CUs attached to the given module should be considered
	 * @return true iff a .java or .class file could be found in the given module / package.
	 */
	boolean hasCompilationUnit(String qualifiedPackageName, String moduleName);

	
Lists all packages in this modulepath entry.
Returns:
array of flat, dot-separated package names/**
	 * Lists all packages in this modulepath entry.
	 * @return array of flat, dot-separated package names
	 */
	default char[][] listPackages() {
		return CharOperation.NO_CHAR_CHAR;
	}

	
Specifies whether this entry represents an automatic module.
Returns:
true if this is an automatic module, false otherwise/**
	 * Specifies whether this entry represents an automatic module.
	 * 
	 * @return true if this is an automatic module, false otherwise
	 */
	public default boolean isAutomaticModule() {
		return false;
	}
}