Java tutorial
/******************************************************************************* * 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 *******************************************************************************/ package org.eclipse.jdt.core.dom; import java.util.ArrayList; import java.util.List; import org.eclipse.jdt.core.compiler.InvalidInputException; import org.eclipse.jdt.internal.compiler.parser.Scanner; import org.eclipse.jdt.internal.compiler.parser.ScannerHelper; import org.eclipse.jdt.internal.compiler.parser.TerminalTokens; import org.eclipse.jdt.internal.compiler.util.Util; /** * Character literal nodes. * * @since 2.0 * @noinstantiate This class is not intended to be instantiated by clients. */ @SuppressWarnings("rawtypes") public class CharacterLiteral extends Expression { /** * The "escapedValue" structural property of this node type (type: {@link String}). * @since 3.0 */ public static final SimplePropertyDescriptor ESCAPED_VALUE_PROPERTY = new SimplePropertyDescriptor( CharacterLiteral.class, "escapedValue", String.class, MANDATORY); //$NON-NLS-1$ /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. */ private static final List PROPERTY_DESCRIPTORS; static { List properyList = new ArrayList(2); createPropertyList(CharacterLiteral.class, properyList); addProperty(ESCAPED_VALUE_PROPERTY, properyList); PROPERTY_DESCRIPTORS = reapPropertyList(properyList); } /** * Returns a list of structural property descriptors for this node type. * Clients must not modify the result. * * @param apiLevel the API level; one of the * <code>AST.JLS*</code> constants * @return a list of property descriptors (element type: * {@link StructuralPropertyDescriptor}) * @since 3.0 */ public static List propertyDescriptors(int apiLevel) { return PROPERTY_DESCRIPTORS; } /** * The literal string, including quotes and escapes; defaults to the * literal for the character 'X'. */ private String escapedValue = "\'X\'";//$NON-NLS-1$ /** * Creates a new unparented character literal node owned by the given AST. * By default, the character literal denotes an unspecified character. * <p> * N.B. This constructor is package-private. * </p> * * @param ast the AST that is to own this node */ CharacterLiteral(AST ast) { super(ast); } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override final Object internalGetSetObjectProperty(SimplePropertyDescriptor property, boolean get, Object value) { if (property == ESCAPED_VALUE_PROPERTY) { if (get) { return getEscapedValue(); } else { setEscapedValue((String) value); return null; } } // allow default implementation to flag the error return super.internalGetSetObjectProperty(property, get, value); } @Override final int getNodeType0() { return CHARACTER_LITERAL; } @Override ASTNode clone0(AST target) { CharacterLiteral result = new CharacterLiteral(target); result.setSourceRange(getStartPosition(), getLength()); result.setEscapedValue(getEscapedValue()); return result; } @Override final boolean subtreeMatch0(ASTMatcher matcher, Object other) { // dispatch to correct overloaded match method return matcher.match(this, other); } @Override void accept0(ASTVisitor visitor) { visitor.visit(this); visitor.endVisit(this); } /** * Returns the string value of this literal node. The value is the sequence * of characters that would appear in the source program, including * enclosing single quotes and embedded escapes. * * @return the escaped string value, including enclosing single quotes * and embedded escapes */ public String getEscapedValue() { return this.escapedValue; } /** * Sets the string value of this literal node. The value is the sequence * of characters that would appear in the source program, including * enclosing single quotes and embedded escapes. For example, * <ul> * <li><code>'a'</code> <code>setEscapedValue("\'a\'")</code></li> * <li><code>'\n'</code> <code>setEscapedValue("\'\\n\'")</code></li> * </ul> * * @param value the string value, including enclosing single quotes * and embedded escapes * @exception IllegalArgumentException if the argument is incorrect */ public void setEscapedValue(String value) { // check setInternalEscapedValue(String) if this method is changed if (value == null) { throw new IllegalArgumentException(); } Scanner scanner = this.ast.scanner; char[] source = value.toCharArray(); scanner.setSource(source); scanner.resetTo(0, source.length); try { int tokenType = scanner.getNextToken(); switch (tokenType) { case TerminalTokens.TokenNameCharacterLiteral: break; default: throw new IllegalArgumentException(); } } catch (InvalidInputException e) { throw new IllegalArgumentException(); } preValueChange(ESCAPED_VALUE_PROPERTY); this.escapedValue = value; postValueChange(ESCAPED_VALUE_PROPERTY); } /* (omit javadoc for this method) * This method is a copy of setEscapedValue(String) that doesn't do any validation. */ void internalSetEscapedValue(String value) { preValueChange(ESCAPED_VALUE_PROPERTY); this.escapedValue = value; postValueChange(ESCAPED_VALUE_PROPERTY); } /** * Returns the value of this literal node. * <p> * For example, * <pre> * CharacterLiteral s; * s.setEscapedValue("\'x\'"); * assert s.charValue() == 'x'; * </pre> * * @return the character value without enclosing quotes and embedded * escapes * @exception IllegalArgumentException if the literal value cannot be converted */ public char charValue() { Scanner scanner = this.ast.scanner; char[] source = this.escapedValue.toCharArray(); scanner.setSource(source); scanner.resetTo(0, source.length); int firstChar = scanner.getNextChar(); int secondChar = scanner.getNextChar(); if (firstChar == -1 || firstChar != '\'') { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } char value = (char) secondChar; int nextChar = scanner.getNextChar(); if (secondChar == '\\') { if (nextChar == -1) { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } switch (nextChar) { case 'b': value = '\b'; break; case 't': value = '\t'; break; case 'n': value = '\n'; break; case 'f': value = '\f'; break; case 'r': value = '\r'; break; case '\"': value = '\"'; break; case '\'': value = '\''; break; case '\\': value = '\\'; break; default: //octal (well-formed: ended by a ' ) try { if (ScannerHelper.isDigit((char) nextChar)) { int number = ScannerHelper.getNumericValue((char) nextChar); nextChar = scanner.getNextChar(); if (nextChar == -1) { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } if (nextChar != '\'') { if (!ScannerHelper.isDigit((char) nextChar)) { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } number = (number * 8) + ScannerHelper.getNumericValue((char) nextChar); nextChar = scanner.getNextChar(); if (nextChar == -1) { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } if (nextChar != '\'') { if (!ScannerHelper.isDigit((char) nextChar)) { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } number = (number * 8) + ScannerHelper.getNumericValue((char) nextChar); } } return (char) number; } else { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } } catch (InvalidInputException e) { throw new IllegalArgumentException("illegal character literal", e);//$NON-NLS-1$ } } nextChar = scanner.getNextChar(); if (nextChar == -1) { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } } if (nextChar == -1 || nextChar != '\'') { throw new IllegalArgumentException("illegal character literal");//$NON-NLS-1$ } return value; } /** * Sets the value of this character literal node to the given character. * <p> * For example, * <pre> * CharacterLiteral s; * s.setCharValue('x'); * assert s.charValue() == 'x'; * assert s.getEscapedValue().equals("\'x\'"); * </pre> * * @param value the character value */ public void setCharValue(char value) { StringBuffer b = new StringBuffer(3); b.append('\''); // opening delimiter Util.appendEscapedChar(b, value, false); b.append('\''); // closing delimiter setEscapedValue(b.toString()); } @Override int memSize() { int size = BASE_NODE_SIZE + 1 * 4 + stringSize(this.escapedValue); return size; } @Override int treeSize() { return memSize(); } }