Java tutorial
/******************************************************************************* * Copyright (c) 2004, 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.core.util; import org.eclipse.jdt.internal.core.JavaElement; public class MementoTokenizer { public static final String COUNT = Character.toString(JavaElement.JEM_COUNT); public static final String JAVAPROJECT = Character.toString(JavaElement.JEM_JAVAPROJECT); public static final String PACKAGEFRAGMENTROOT = Character.toString(JavaElement.JEM_PACKAGEFRAGMENTROOT); public static final String PACKAGEFRAGMENT = Character.toString(JavaElement.JEM_PACKAGEFRAGMENT); public static final String FIELD = Character.toString(JavaElement.JEM_FIELD); public static final String METHOD = Character.toString(JavaElement.JEM_METHOD); public static final String INITIALIZER = Character.toString(JavaElement.JEM_INITIALIZER); public static final String COMPILATIONUNIT = Character.toString(JavaElement.JEM_COMPILATIONUNIT); public static final String CLASSFILE = Character.toString(JavaElement.JEM_CLASSFILE); public static final String MODULAR_CLASSFILE = Character.toString(JavaElement.JEM_MODULAR_CLASSFILE); public static final String TYPE = Character.toString(JavaElement.JEM_TYPE); public static final String MODULE = Character.toString(JavaElement.JEM_MODULE); public static final String PACKAGEDECLARATION = Character.toString(JavaElement.JEM_PACKAGEDECLARATION); public static final String IMPORTDECLARATION = Character.toString(JavaElement.JEM_IMPORTDECLARATION); public static final String LOCALVARIABLE = Character.toString(JavaElement.JEM_LOCALVARIABLE); public static final String TYPE_PARAMETER = Character.toString(JavaElement.JEM_TYPE_PARAMETER); public static final String ANNOTATION = Character.toString(JavaElement.JEM_ANNOTATION); public static final String LAMBDA_EXPRESSION = Character.toString(JavaElement.JEM_LAMBDA_EXPRESSION); public static final String LAMBDA_METHOD = Character.toString(JavaElement.JEM_LAMBDA_METHOD); public static final String STRING = Character.toString(JavaElement.JEM_STRING); public static final String CLASSPATH_ATTRIBUTE = JAVAPROJECT + PACKAGEFRAGMENTROOT; private final char[] memento; private final int length; private int index = 0; public MementoTokenizer(String memento) { this.memento = memento.toCharArray(); this.length = this.memento.length; } public boolean hasMoreTokens() { return this.index < this.length; } public String nextToken() { int start = this.index; StringBuffer buffer = null; switch (this.memento[this.index++]) { case JavaElement.JEM_ESCAPE: buffer = new StringBuffer(); buffer.append(this.memento[this.index]); start = ++this.index; break; case JavaElement.JEM_COUNT: return COUNT; case JavaElement.JEM_JAVAPROJECT: // Also covers JavaElement#JEM_DELIMITER_ESCAPE, in which case, // we seek ahead by one char and check if it's an escaped delimiter // and if that's true, we return that as the token. // Else, we decide that JEM_JAVAPROJECT is the current token. if (this.index < this.length) { char nextChar = this.memento[this.index++]; switch (nextChar) { case JavaElement.JEM_LAMBDA_EXPRESSION: return LAMBDA_EXPRESSION; case JavaElement.JEM_LAMBDA_METHOD: return LAMBDA_METHOD; case JavaElement.JEM_STRING: return STRING; case JavaElement.JEM_PACKAGEFRAGMENTROOT: return CLASSPATH_ATTRIBUTE; default: this.index--; break; } } return JAVAPROJECT; case JavaElement.JEM_PACKAGEFRAGMENTROOT: return PACKAGEFRAGMENTROOT; case JavaElement.JEM_PACKAGEFRAGMENT: return PACKAGEFRAGMENT; case JavaElement.JEM_FIELD: return FIELD; case JavaElement.JEM_METHOD: return METHOD; case JavaElement.JEM_INITIALIZER: return INITIALIZER; case JavaElement.JEM_COMPILATIONUNIT: return COMPILATIONUNIT; case JavaElement.JEM_CLASSFILE: return CLASSFILE; case JavaElement.JEM_MODULAR_CLASSFILE: return MODULAR_CLASSFILE; case JavaElement.JEM_TYPE: return TYPE; case JavaElement.JEM_MODULE: return MODULE; case JavaElement.JEM_PACKAGEDECLARATION: return PACKAGEDECLARATION; case JavaElement.JEM_IMPORTDECLARATION: return IMPORTDECLARATION; case JavaElement.JEM_LOCALVARIABLE: return LOCALVARIABLE; case JavaElement.JEM_TYPE_PARAMETER: return TYPE_PARAMETER; case JavaElement.JEM_ANNOTATION: return ANNOTATION; } loop: while (this.index < this.length) { switch (this.memento[this.index]) { case JavaElement.JEM_ESCAPE: if (buffer == null) buffer = new StringBuffer(); buffer.append(this.memento, start, this.index - start); start = ++this.index; if (this.memento[this.index] == JavaElement.JEM_MODULE) return buffer.toString(); break; case JavaElement.JEM_COUNT: case JavaElement.JEM_JAVAPROJECT: case JavaElement.JEM_PACKAGEFRAGMENTROOT: case JavaElement.JEM_PACKAGEFRAGMENT: case JavaElement.JEM_FIELD: case JavaElement.JEM_METHOD: case JavaElement.JEM_INITIALIZER: case JavaElement.JEM_COMPILATIONUNIT: case JavaElement.JEM_CLASSFILE: case JavaElement.JEM_TYPE: case JavaElement.JEM_MODULE: case JavaElement.JEM_PACKAGEDECLARATION: case JavaElement.JEM_IMPORTDECLARATION: case JavaElement.JEM_LOCALVARIABLE: case JavaElement.JEM_TYPE_PARAMETER: case JavaElement.JEM_ANNOTATION: break loop; } this.index++; } if (buffer != null) { buffer.append(this.memento, start, this.index - start); return buffer.toString(); } else { return new String(this.memento, start, this.index - start); } } public String getStringDelimitedBy(String delimiter) { String token = nextToken(); if (token == delimiter) return ""; //$NON-NLS-1$ String separator = nextToken(); assert separator == delimiter; return token; } }