/* * Copyright (c) 2005, 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. */ /* ******************************************************************************* * (C) Copyright IBM Corp. 1996-2005 - All Rights Reserved * * * * The original version of this source code and documentation is copyrighted * * and owned by IBM, These materials are provided under terms of a License * * Agreement between IBM and Sun. This technology is protected by multiple * * US and International patents. This notice and attribution to IBM may not * * to removed. * ******************************************************************************* */ /* ********************************************************************** * Author: Alan Liu * Created: September 23 2003 * Since: ICU 2.8 ********************************************************************** */ package sun.text.normalizer; import java.text.ParsePosition; /** * An iterator that returns 32-bit code points. This class is deliberately * <em>not</em> related to any of the JDK or ICU4J character iterator classes * in order to minimize complexity. * @author Alan Liu * @since ICU 2.8 */public class RuleCharacterIterator { // TODO: Ideas for later. (Do not implement if not needed, lest the // code coverage numbers go down due to unused methods.) // 1. Add a copy constructor, equals() method, clone() method. // 2. Rather than return DONE, throw an exception if the end // is reached -- this is an alternate usage model, probably not useful. // 3. Return isEscaped from next(). If this happens, // don't keep an isEscaped member variable. /** * Text being iterated. */ private String text; /** * Position of iterator. */ private ParsePosition pos; /** * Symbol table used to parse and dereference variables. May be null. */ private SymbolTable sym; /** * Current variable expansion, or null if none. */ private char[] buf; /** * Position within buf[]. Meaningless if buf == null. */ private int bufPos; /** * Flag indicating whether the last character was parsed from an escape. */ private boolean isEscaped; /** * Value returned when there are no more characters to iterate. */ public static final int DONE = -1; /** * Bitmask option to enable parsing of variable names. If (options & * PARSE_VARIABLES) != 0, then an embedded variable will be expanded to * its value. Variables are parsed using the SymbolTable API. */ public static final int PARSE_VARIABLES = 1; /** * Bitmask option to enable parsing of escape sequences. If (options & * PARSE_ESCAPES) != 0, then an embedded escape sequence will be expanded * to its value. Escapes are parsed using Utility.unescapeAt(). */ public static final int PARSE_ESCAPES = 2; /** * Bitmask option to enable skipping of whitespace. If (options & * SKIP_WHITESPACE) != 0, then whitespace characters will be silently * skipped, as if they were not present in the input. Whitespace * characters are defined by UCharacterProperty.isRuleWhiteSpace(). */ public static final int SKIP_WHITESPACE = 4; /** * Constructs an iterator over the given text, starting at the given * position. * @param text the text to be iterated * @param sym the symbol table, or null if there is none. If sym is null, * then variables will not be deferenced, even if the PARSE_VARIABLES * option is set. * @param pos upon input, the index of the next character to return. If a * variable has been dereferenced, then pos will <em>not</em> increment as * characters of the variable value are iterated. */ public RuleCharacterIterator(String text, SymbolTable sym, ParsePosition pos) { if (text == null || pos.getIndex() > text.length()) { throw new IllegalArgumentException(); } this.text = text; this.sym = sym; this.pos = pos; buf = null; } /** * Returns true if this iterator has no more characters to return. */ public boolean atEnd() { return buf == null && pos.getIndex() == text.length(); } /** * Returns the next character using the given options, or DONE if there * are no more characters, and advance the position to the next * character. * @param options one or more of the following options, bitwise-OR-ed * together: PARSE_VARIABLES, PARSE_ESCAPES, SKIP_WHITESPACE. * @return the current 32-bit code point, or DONE */ public int next(int options) { int c = DONE; isEscaped = false; for (;;) { c = _current(); _advance(UTF16.getCharCount(c)); if (c == SymbolTable.SYMBOL_REF && buf == null && (options & PARSE_VARIABLES) != 0 && sym != null) { String name = sym.parseReference(text, pos, text.length()); // If name == null there was an isolated SYMBOL_REF; // return it. Caller must be prepared for this. if (name == null) { break; } bufPos = 0; buf = sym.lookup(name); if (buf == null) { throw new IllegalArgumentException( "Undefined variable: " + name); } // Handle empty variable value if (buf.length == 0) { buf = null; } continue; } if ((options & SKIP_WHITESPACE) != 0 && UCharacterProperty.isRuleWhiteSpace(c)) { continue; } if (c == '\\' && (options & PARSE_ESCAPES) != 0) { int offset[] = new int[] { 0 }; c = Utility.unescapeAt(lookahead(), offset); jumpahead(offset[0]); isEscaped = true; if (c < 0) { throw new IllegalArgumentException("Invalid escape"); } } break; } return c; } /** * Returns true if the last character returned by next() was * escaped. This will only be the case if the option passed in to * next() included PARSE_ESCAPED and the next character was an * escape sequence. */ public boolean isEscaped() { return isEscaped; } /** * Returns true if this iterator is currently within a variable expansion. */ public boolean inVariable() { return buf != null; } /** * Returns an object which, when later passed to setPos(), will * restore this iterator's position. Usage idiom: * * RuleCharacterIterator iterator = ...; * Object pos = iterator.getPos(null); // allocate position object * for (;;) { * pos = iterator.getPos(pos); // reuse position object * int c = iterator.next(...); * ... * } * iterator.setPos(pos); * * @param p a position object previously returned by getPos(), * or null. If not null, it will be updated and returned. If * null, a new position object will be allocated and returned. * @return a position object which may be passed to setPos(), * either `p,' or if `p' == null, a newly-allocated object */ public Object getPos(Object p) { if (p == null) { return new Object[] {buf, new int[] {pos.getIndex(), bufPos}}; } Object[] a = (Object[]) p; a[0] = buf; int[] v = (int[]) a[1]; v[0] = pos.getIndex(); v[1] = bufPos; return p; } /** * Restores this iterator to the position it had when getPos() * returned the given object. * @param p a position object previously returned by getPos() */ public void setPos(Object p) { Object[] a = (Object[]) p; buf = (char[]) a[0]; int[] v = (int[]) a[1]; pos.setIndex(v[0]); bufPos = v[1]; } /** * Skips ahead past any ignored characters, as indicated by the given * options. This is useful in conjunction with the lookahead() method. * * Currently, this only has an effect for SKIP_WHITESPACE. * @param options one or more of the following options, bitwise-OR-ed * together: PARSE_VARIABLES, PARSE_ESCAPES, SKIP_WHITESPACE. */ public void skipIgnored(int options) { if ((options & SKIP_WHITESPACE) != 0) { for (;;) { int a = _current(); if (!UCharacterProperty.isRuleWhiteSpace(a)) break; _advance(UTF16.getCharCount(a)); } } } /** * Returns a string containing the remainder of the characters to be * returned by this iterator, without any option processing. If the * iterator is currently within a variable expansion, this will only * extend to the end of the variable expansion. This method is provided * so that iterators may interoperate with string-based APIs. The typical * sequence of calls is to call skipIgnored(), then call lookahead(), then * parse the string returned by lookahead(), then call jumpahead() to * resynchronize the iterator. * @return a string containing the characters to be returned by future * calls to next() */ public String lookahead() { if (buf != null) { return new String(buf, bufPos, buf.length - bufPos); } else { return text.substring(pos.getIndex()); } } /** * Advances the position by the given number of 16-bit code units. * This is useful in conjunction with the lookahead() method. * @param count the number of 16-bit code units to jump over */ public void jumpahead(int count) { if (count < 0) { throw new IllegalArgumentException(); } if (buf != null) { bufPos += count; if (bufPos > buf.length) { throw new IllegalArgumentException(); } if (bufPos == buf.length) { buf = null; } } else { int i = pos.getIndex() + count; pos.setIndex(i); if (i > text.length()) { throw new IllegalArgumentException(); } } } /** * Returns the current 32-bit code point without parsing escapes, parsing * variables, or skipping whitespace. * @return the current 32-bit code point */ private int _current() { if (buf != null) { return UTF16.charAt(buf, 0, buf.length, bufPos); } else { int i = pos.getIndex(); return (i < text.length()) ? UTF16.charAt(text, i) : DONE; } } /** * Advances the position by the given amount. * @param count the number of 16-bit code units to advance past */ private void _advance(int count) { if (buf != null) { bufPos += count; if (bufPos == buf.length) { buf = null; } } else { pos.setIndex(pos.getIndex() + count); if (pos.getIndex() > text.length()) { pos.setIndex(text.length()); } } }}
/*
* Copyright (c) 2005, 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.
*/
/*
*******************************************************************************
* (C) Copyright IBM Corp. 1996-2005 - All Rights Reserved *
* *
* The original version of this source code and documentation is copyrighted *
* and owned by IBM, These materials are provided under terms of a License *
* Agreement between IBM and Sun. This technology is protected by multiple *
* US and International patents. This notice and attribution to IBM may not *
* to removed. *
*******************************************************************************
*/
/*
**********************************************************************
* Author: Alan Liu
* Created: September 23 2003
* Since: ICU 2.8
**********************************************************************
*/
package sun.text.normalizer;
import java.text.ParsePosition;
/**
* An iterator that returns 32-bit code points. This class is deliberately
* <em>not</em> related to any of the JDK or ICU4J character iterator classes
* in order to minimize complexity.
* @author Alan Liu
* @since ICU 2.8
*/
public class RuleCharacterIterator {
// TODO: Ideas for later. (Do not implement if not needed, lest the
// code coverage numbers go down due to unused methods.)
// 1. Add a copy constructor, equals() method, clone() method.
// 2. Rather than return DONE, throw an exception if the end
// is reached -- this is an alternate usage model, probably not useful.
// 3. Return isEscaped from next(). If this happens,
// don't keep an isEscaped member variable.
/**
* Text being iterated.
*/
private String text;
/**
* Position of iterator.
*/
private ParsePosition pos;
/**
* Symbol table used to parse and dereference variables. May be null.
*/
private SymbolTable sym;
/**
* Current variable expansion, or null if none.
*/
private char[] buf;
/**
* Position within buf[]. Meaningless if buf == null.
*/
private int bufPos;
/**
* Flag indicating whether the last character was parsed from an escape.
*/
private boolean isEscaped;
/**
* Value returned when there are no more characters to iterate.
*/
public static final int DONE = -1;
/**
* Bitmask option to enable parsing of variable names. If (options &
* PARSE_VARIABLES) != 0, then an embedded variable will be expanded to
* its value. Variables are parsed using the SymbolTable API.
*/
public static final int PARSE_VARIABLES = 1;
/**
* Bitmask option to enable parsing of escape sequences. If (options &
* PARSE_ESCAPES) != 0, then an embedded escape sequence will be expanded
* to its value. Escapes are parsed using Utility.unescapeAt().
*/
public static final int PARSE_ESCAPES = 2;
/**
* Bitmask option to enable skipping of whitespace. If (options &
* SKIP_WHITESPACE) != 0, then whitespace characters will be silently
* skipped, as if they were not present in the input. Whitespace
* characters are defined by UCharacterProperty.isRuleWhiteSpace().
*/
public static final int SKIP_WHITESPACE = 4;
/**
* Constructs an iterator over the given text, starting at the given
* position.
* @param text the text to be iterated
* @param sym the symbol table, or null if there is none. If sym is null,
* then variables will not be deferenced, even if the PARSE_VARIABLES
* option is set.
* @param pos upon input, the index of the next character to return. If a
* variable has been dereferenced, then pos will <em>not</em> increment as
* characters of the variable value are iterated.
*/
public RuleCharacterIterator(String text, SymbolTable sym,
ParsePosition pos) {
if (text == null || pos.getIndex() > text.length()) {
throw new IllegalArgumentException();
}
this.text = text;
this.sym = sym;
this.pos = pos;
buf = null;
}
/**
* Returns true if this iterator has no more characters to return.
*/
public boolean atEnd() {
return buf == null && pos.getIndex() == text.length();
}
/**
* Returns the next character using the given options, or DONE if there
* are no more characters, and advance the position to the next
* character.
* @param options one or more of the following options, bitwise-OR-ed
* together: PARSE_VARIABLES, PARSE_ESCAPES, SKIP_WHITESPACE.
* @return the current 32-bit code point, or DONE
*/
public int next(int options) {
int c = DONE;
isEscaped = false;
for (;;) {
c = _current();
_advance(UTF16.getCharCount(c));
if (c == SymbolTable.SYMBOL_REF && buf == null &&
(options & PARSE_VARIABLES) != 0 && sym != null) {
String name = sym.parseReference(text, pos, text.length());
// If name == null there was an isolated SYMBOL_REF;
// return it. Caller must be prepared for this.
if (name == null) {
break;
}
bufPos = 0;
buf = sym.lookup(name);
if (buf == null) {
throw new IllegalArgumentException(
"Undefined variable: " + name);
}
// Handle empty variable value
if (buf.length == 0) {
buf = null;
}
continue;
}
if ((options & SKIP_WHITESPACE) != 0 &&
UCharacterProperty.isRuleWhiteSpace(c)) {
continue;
}
if (c == '\\' && (options & PARSE_ESCAPES) != 0) {
int offset[] = new int[] { 0 };
c = Utility.unescapeAt(lookahead(), offset);
jumpahead(offset[0]);
isEscaped = true;
if (c < 0) {
throw new IllegalArgumentException("Invalid escape");
}
}
break;
}
return c;
}
/**
* Returns true if the last character returned by next() was
* escaped. This will only be the case if the option passed in to
* next() included PARSE_ESCAPED and the next character was an
* escape sequence.
*/
public boolean isEscaped() {
return isEscaped;
}
/**
* Returns true if this iterator is currently within a variable expansion.
*/
public boolean inVariable() {
return buf != null;
}
/**
* Returns an object which, when later passed to setPos(), will
* restore this iterator's position. Usage idiom:
*
* RuleCharacterIterator iterator = ...;
* Object pos = iterator.getPos(null); // allocate position object
* for (;;) {
* pos = iterator.getPos(pos); // reuse position object
* int c = iterator.next(...);
* ...
* }
* iterator.setPos(pos);
*
* @param p a position object previously returned by getPos(),
* or null. If not null, it will be updated and returned. If
* null, a new position object will be allocated and returned.
* @return a position object which may be passed to setPos(),
* either `p,' or if `p' == null, a newly-allocated object
*/
public Object getPos(Object p) {
if (p == null) {
return new Object[] {buf, new int[] {pos.getIndex(), bufPos}};
}
Object[] a = (Object[]) p;
a[0] = buf;
int[] v = (int[]) a[1];
v[0] = pos.getIndex();
v[1] = bufPos;
return p;
}
/**
* Restores this iterator to the position it had when getPos()
* returned the given object.
* @param p a position object previously returned by getPos()
*/
public void setPos(Object p) {
Object[] a = (Object[]) p;
buf = (char[]) a[0];
int[] v = (int[]) a[1];
pos.setIndex(v[0]);
bufPos = v[1];
}
/**
* Skips ahead past any ignored characters, as indicated by the given
* options. This is useful in conjunction with the lookahead() method.
*
* Currently, this only has an effect for SKIP_WHITESPACE.
* @param options one or more of the following options, bitwise-OR-ed
* together: PARSE_VARIABLES, PARSE_ESCAPES, SKIP_WHITESPACE.
*/
public void skipIgnored(int options) {
if ((options & SKIP_WHITESPACE) != 0) {
for (;;) {
int a = _current();
if (!UCharacterProperty.isRuleWhiteSpace(a)) break;
_advance(UTF16.getCharCount(a));
}
}
}
/**
* Returns a string containing the remainder of the characters to be
* returned by this iterator, without any option processing. If the
* iterator is currently within a variable expansion, this will only
* extend to the end of the variable expansion. This method is provided
* so that iterators may interoperate with string-based APIs. The typical
* sequence of calls is to call skipIgnored(), then call lookahead(), then
* parse the string returned by lookahead(), then call jumpahead() to
* resynchronize the iterator.
* @return a string containing the characters to be returned by future
* calls to next()
*/
public String lookahead() {
if (buf != null) {
return new String(buf, bufPos, buf.length - bufPos);
} else {
return text.substring(pos.getIndex());
}
}
/**
* Advances the position by the given number of 16-bit code units.
* This is useful in conjunction with the lookahead() method.
* @param count the number of 16-bit code units to jump over
*/
public void jumpahead(int count) {
if (count < 0) {
throw new IllegalArgumentException();
}
if (buf != null) {
bufPos += count;
if (bufPos > buf.length) {
throw new IllegalArgumentException();
}
if (bufPos == buf.length) {
buf = null;
}
} else {
int i = pos.getIndex() + count;
pos.setIndex(i);
if (i > text.length()) {
throw new IllegalArgumentException();
}
}
}
/**
* Returns the current 32-bit code point without parsing escapes, parsing
* variables, or skipping whitespace.
* @return the current 32-bit code point
*/
private int _current() {
if (buf != null) {
return UTF16.charAt(buf, 0, buf.length, bufPos);
} else {
int i = pos.getIndex();
return (i < text.length()) ? UTF16.charAt(text, i) : DONE;
}
}
/**
* Advances the position by the given amount.
* @param count the number of 16-bit code units to advance past
*/
private void _advance(int count) {
if (buf != null) {
bufPos += count;
if (bufPos == buf.length) {
buf = null;
}
} else {
pos.setIndex(pos.getIndex() + count);
if (pos.getIndex() > text.length()) {
pos.setIndex(text.length());
}
}
}
}