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/*
* @(#)RuleBasedCollator.java 1.21 98/02/12
*
* (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
* (C) Copyright IBM Corp. 1996, 1997 - All Rights Reserved
*
* Portions copyright (c) 1996 Sun Microsystems, Inc. All Rights Reserved.
*
* The original version of this source code and documentation is copyrighted
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
* materials are provided under terms of a License Agreement between Taligent
* and Sun. This technology is protected by multiple US and International
* patents. This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
* Permission to use, copy, modify, and distribute this software
* and its documentation for NON-COMMERCIAL purposes and without
* fee is hereby granted provided that this copyright notice
* appears in all copies. Please refer to the file "copyright.html"
* for further important copyright and licensing information.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
* THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
* TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
*
*/
package java.text;
import java.util.Vector;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
/**
* The <code>RuleBasedCollator</code> class is a concrete subclass of
* <code>Collator</code> that provides a simple, data-driven, table collator.
* With this class you can create a customized table-based <code>Collator</code>.
* <code>RuleBasedCollator</code> maps characters to sort keys.
*
* <p>
* <code>RuleBasedCollator</code> has the following restrictions
* for efficiency (other subclasses may be used for more complex languages) :
* <ol>
* <li>If a French secondary ordering is specified it applies to the
* whole collator object.
* <li>All non-mentioned Unicode characters are at the end of the
* collation order.
* <li>Private use characters are treated as identical. The private
* use area in Unicode is <code>0xE800</code>-<code>0xF8FF</code>.
* </ol>
*
* <p>
* The collation table is composed of a list of collation rules, where each
* rule is of three forms:
* <pre>
* < modifier >
* < relation > < text-argument >
* < reset > < text-argument >
* </pre>
* The following demonstrates how to create your own collation rules:
* <UL Type=round>
* <LI><strong>Text-Argument</strong>: A text-argument is any sequence of
* characters, excluding special characters (that is, whitespace
* characters and the characters used in modifier, relation and reset).
* If those characters are desired, you can put them in single quotes
* (e.g. ampersand => '&'). Note that unquoted white space characters
* are ignored; e.g. <code>b c</code> is treated as <code>bc</code>.
* <LI><strong>Modifier</strong>: There is a single modifier
* which is used to specify that all accents (secondary differences) are
* backwards.
* <p>'@' : Indicates that accents are sorted backwards, as in French.
* <LI><strong>Relation</strong>: The relations are the following:
* <UL Type=square>
* <LI>'<' : Greater, as a letter difference (primary)
* <LI>';' : Greater, as an accent difference (secondary)
* <LI>',' : Greater, as a case difference (tertiary)
* <LI>'=' : Equal
* </UL>
* <LI><strong>Reset</strong>: There is a single reset
* which is used primarily for contractions and expansions, but which
* can also be used to add a modification at the end of a set of rules.
* <p>'&' : Indicates that the next rule follows the position to where
* the reset text-argument would be sorted.
* </UL>
*
* <p>
* This sounds more complicated than it is in practice. For example, the
* following are equivalent ways of expressing the same thing:
* <blockquote>
* <pre>
* a < b < c
* a < b & b < c
* a < c & a < b
* </pre>
* </blockquote>
* Notice that the order is important, as the subsequent item goes immediately
* after the text-argument. The following are not equivalent:
* <blockquote>
* <pre>
* a < b & a < c
* a < c & a < b
* </pre>
* </blockquote>
* Either the text-argument must already be present in the sequence, or some
* initial substring of the text-argument must be present. (e.g. "a < b & ae <
* e" is valid since "a" is present in the sequence before "ae" is reset). In
* this latter case, "ae" is not entered and treated as a single character;
* instead, "e" is sorted as if it were expanded to two characters: "a"
* followed by an "e". This difference appears in natural languages: in
* traditional Spanish "ch" is treated as though it contracts to a single
* character (expressed as "c < ch < d"), while in traditional German "Σ"
* (a-umlaut) is treated as though it expands to two characters (expressed as
* "a & ae ; Σ < b").
*
* <p>
* <strong>Ignorable Characters</strong>
* <p>
* For ignorable characters, the first rule must start with a relation (the
* examples we have used above are really fragments; "a < b" really should be
* "< a < b"). If, however, the first relation is not "<", then all the all
* text-arguments up to the first "<" are ignorable. For example, ", - < a < b"
* makes "-" an ignorable character, as we saw earlier in the word
* "black-birds". In the samples for different languages, you see that most
* accents are ignorable.
*
* <p><strong>Normalization and Accents</strong>
* <p>
* The <code>Collator</code> object automatically normalizes text internally
* to separate accents from base characters where possible. This is done both when
* processing the rules, and when comparing two strings. <code>Collator</code>
* also uses the Unicode canonical mapping to ensure that combining sequences
* are sorted properly (for more information, see
* <A HREF="http://www.aw.com/devpress">The Unicode Standard, Version 2.0</A>.)</P>
*
* <p><strong>Errors</strong>
* <p>
* The following are errors:
* <UL Type=round>
* <LI>A text-argument contains unquoted punctuation symbols
* (e.g. "a < b-c < d").
* <LI>A relation or reset character not followed by a text-argument
* (e.g. "a < , b").
* <LI>A reset where the text-argument (or an initial substring of the
* text-argument) is not already in the sequence.
* (e.g. "a < b & e < f")
* </UL>
* If you produce one of these errors, a <code>RuleBasedCollator</code> throws
* a <code>ParseException</code>.
*
* <p><strong>Examples</strong>
* <p>Simple: "< a < b < c < d"
* <p>Norwegian: "< a,A< b,B< c,C< d,D< e,E< f,F< g,G< h,H< i,I< j,J
* < k,K< l,L< m,M< n,N< o,O< p,P< q,Q< r,R< s,S< t,T
* < u,U< v,V< w,W< x,X< y,Y< z,Z
* < \u00E5=a\u030A,\u00C5=A\u030A
* ;aa,AA< \u00E6,\u00C6< \u00F8,\u00D8"
*
* <p>
* Normally, to create a rule-based Collator object, you will use
* <code>Collator</code>'s factory method <code>getInstance</code>.
* However, to create a rule-based Collator object with specialized
* rules tailored to your needs, you construct the <code>RuleBasedCollator</code>
* with the rules contained in a <code>String</code> object. For example:
* <blockquote>
* <pre>
* String Simple = "< a < b < c < d";
* RuleBasedCollator mySimple = new RuleBasedCollator(Simple);
* </pre>
* </blockquote>
* Or:
* <blockquote>
* <pre>
* String Norwegian = "< a,A< b,B< c,C< d,D< e,E< f,F< g,G< h,H< i,I< j,J" +
* "< k,K< l,L< m,M< n,N< o,O< p,P< q,Q< r,R< s,S< t,T" +
* "< u,U< v,V< w,W< x,X< y,Y< z,Z" +
* "< \u00E5=a\u030A,\u00C5=A\u030A" +
* ";aa,AA< \u00E6,\u00C6< \u00F8,\u00D8";
* RuleBasedCollator myNorwegian = new RuleBasedCollator(Norwegian);
* </pre>
* </blockquote>
*
* <p>
* Combining <code>Collator</code>s is as simple as concatenating strings.
* Here's an example that combines two <code>Collator</code>s from two
* different locales:
* <blockquote>
* <pre>
* // Create an en_US Collator object
* RuleBasedCollator en_USCollator = (RuleBasedCollator)
* Collator.getInstance(new Locale("en", "US", ""));
* // Create a da_DK Collator object
* RuleBasedCollator da_DKCollator = (RuleBasedCollator)
* Collator.getInstance(new Locale("da", "DK", ""));
* // Combine the two
* // First, get the collation rules from en_USCollator
* String en_USRules = en_USCollator.getRules();
* // Second, get the collation rules from da_DKCollator
* String da_DKRules = da_DKCollator.getRules();
* RuleBasedCollator newCollator =
* new RuleBasedCollator(en_USRules + da_DKRules);
* // newCollator has the combined rules
* </pre>
* </blockquote>
*
* <p>
* Another more interesting example would be to make changes on an existing
* table to create a new <code>Collator</code> object. For example, add
* "& C < ch, cH, Ch, CH" to the <code>en_USCollator</code> object to create
* your own:
* <blockquote>
* <pre>
* // Create a new Collator object with additional rules
* String addRules = "& C < ch, cH, Ch, CH";
* RuleBasedCollator myCollator =
* new RuleBasedCollator(en_USCollator + addRules);
* // myCollator contains the new rules
* </pre>
* </blockquote>
*
* <p>
* The following example demonstrates how to change the order of
* non-spacing accents,
* <blockquote>
* <pre>
* // old rule
* String oldRules = "=\u0301;\u0300;\u0302;\u0308" // main accents
* + ";\u0327;\u0303;\u0304;\u0305" // main accents
* + ";\u0306;\u0307;\u0309;\u030A" // main accents
* + ";\u030B;\u030C;\u030D;\u030E" // main accents
* + ";\u030F;\u0310;\u0311;\u0312" // main accents
* + "< a , A ; ae, AE ; \u00e6 , \u00c6"
* + "< b , B < c, C < e, E & C < d, D";
* // change the order of accent characters
* String addOn = "& \u0300 ; \u0308 ; \u0302";
* RuleBasedCollator myCollator = new RuleBasedCollator(oldRules + addOn);
* </pre>
* </blockquote>
*
* <p>
* The last example shows how to put new primary ordering in before the
* default setting. For example, in Japanese <code>Collator</code>, you
* can either sort English characters before or after Japanese characters,
* <blockquote>
* <pre>
* // get en_US Collator rules
* RuleBasedCollator en_USCollator = (RuleBasedCollator)Collator.getInstance(Locale.US);
* // add a few Japanese character to sort before English characters
* // suppose the last character before the first base letter 'a' in
* // the English collation rule is \u2212
* String jaString = "& \u2212 < \u3041, \u3042 < \u3043, \u3044";
* RuleBasedCollator myJapaneseCollator = new
* RuleBasedCollator(en_USCollator.getRules() + jaString);
* </pre>
* </blockquote>
*
* @see Collator
* @see CollationElementIterator
* @version 1.21 02/12/98
* @author Helena Shih
*/
public class RuleBasedCollator extends Collator{
//===========================================================================================
// The following diagram shows the data structure of the RuleBasedCollator object.
// Suppose we have the rule, where 'o-umlaut' is the unicode char 0x00F6.
// "a, A < b, B < c, C, ch, cH, Ch, CH < d, D ... < o, O; 'o-umlaut'/E, 'O-umlaut'/E ...".
// What the rule says is, sorts 'ch'ligatures and 'c' only with tertiary difference and
// sorts 'o-umlaut' as if it's always expanded with 'e'.
//
// mapping table contracting list expanding list
// (contains all unicode char
// entries) ___ ____________ _________________________
// ________ +>|_*_|->|'c' |v('c') | +>|v('o')|v('umlaut')|v('e')|
// |_\u0001_|-> v('\u0001') | |_:_| |------------| | |-------------------------|
// |_\u0002_|-> v('\u0002') | |_:_| |'ch'|v('ch')| | | : |
// |____:___| | |_:_| |------------| | |-------------------------|
// |____:___| | |'cH'|v('cH')| | | : |
// |__'a'___|-> v('a') | |------------| | |-------------------------|
// |__'b'___|-> v('b') | |'Ch'|v('Ch')| | | : |
// |____:___| | |------------| | |-------------------------|
// |____:___| | |'CH'|v('CH')| | | : |
// |___'c'__|---------------- ------------ | |-------------------------|
// |____:___| | | : |
// |o-umlaut|---------------------------------------- |_________________________|
// |____:___|
//
// Noted by Helena Shih on 6/23/97
//============================================================================================
/**
* RuleBasedCollator constructor. This takes the table rules and builds
* a collation table out of them. Please see RuleBasedCollator class
* description for more details on the collation rule syntax.
* @see java.util.Locale
* @param rules the collation rules to build the collation table from.
* @exception ParseException A format exception
* will be thrown if the build process of the rules fails. For
* example, build rule "a < ? < d" will cause the constructor to
* throw the ParseException because the '?' is not quoted.
*/
public RuleBasedCollator(String rules) throws ParseException {
setStrength(Collator.TERTIARY);
build(rules);
}
/**
* Gets the table-based rules for the collation object.
* @return returns the collation rules that the table collation object
* was created from.
*/
public String getRules()
{
if (ruleTable == null) {
ruleTable = mPattern.emitPattern();
mPattern = null;
}
return ruleTable;
}
/**
* Return a CollationElementIterator for the given String.
* @see java.text.CollationElementIterator
*/
public CollationElementIterator getCollationElementIterator(String source) {
return new CollationElementIterator( source, this );
}
/**
* Compares the character data stored in two different strings based on the
* collation rules. Returns information about whether a string is less
* than, greater than or equal to another string in a language.
* This can be overriden in a subclass.
*/
public int compare(String source, String target)
{
// The basic algorithm here is that we use CollationElementIterators
// to step through both the source and target strings. We compare each
// collation element in the source string against the corresponding one
// in the target, checking for differences.
//
// If a difference is found, we set <result> to LESS or GREATER to
// indicate whether the source string is less or greater than the target.
//
// However, it's not that simple. If we find a tertiary difference
// (e.g. 'A' vs. 'a') near the beginning of a string, it can be
// overridden by a primary difference (e.g. "A" vs. "B") later in
// the string. For example, "AA" < "aB", even though 'A' > 'a'.
//
// To keep track of this, we use strengthResult to keep track of the
// strength of the most significant difference that has been found
// so far. When we find a difference whose strength is greater than
// strengthResult, it overrides the last difference (if any) that
// was found.
int result = Collator.EQUAL;
strengthResult = Collator.IDENTICAL;
CollationElementIterator targetCursor
= new CollationElementIterator(target, this);
CollationElementIterator sourceCursor
= new CollationElementIterator(source, this);
int sOrder = 0, tOrder = 0;
int savedSOrder = 0, savedTOrder = 0;
boolean skipSecCheck = false;
boolean gets = true, gett = true;
while(true) {
// Get the next collation element in each of the strings, unless
// we've been requested to skip it.
int pSOrder = 0, pTOrder = 0;
if (gets) sOrder = sourceCursor.next(); else gets = true;
if (gett) tOrder = targetCursor.next(); else gett = true;
// If we've hit the end of one of the strings, jump out of the loop
if ((sOrder == CollationElementIterator.NULLORDER)||
(tOrder == CollationElementIterator.NULLORDER))
break;
// When we hit the end of one of the strings, we're going to need to remember
// the last element in each string, in order to decide if there
savedSOrder = sOrder;
savedTOrder = tOrder;
// If there's no difference at this position, we can skip it
if (sOrder == tOrder)
continue;
// Compare primary differences first.
pSOrder = CollationElementIterator.primaryOrder(sOrder);
pTOrder = CollationElementIterator.primaryOrder(tOrder);
if ( pSOrder != pTOrder )
{
if (sOrder == 0) {
// The entire source element is ignorable. Skip to the
//next source element, but don't fetch another target element.
gett = false;
continue;
}
if (tOrder == 0) {
gets = false;
continue;
}
// Neither the source or target order is totally ignorable,
// but it's still possible for the primary component of one of the
// elements to be ignorable, e.g. for a combining accent mark
if (pSOrder == 0) // primary order in source is ignorable
{
if (pTOrder == 0) // primary order in target is ignorable
{
// check the secondary/tertiary weight when both are ignorable chars.
result = checkSecTerDiff(sOrder, tOrder, result, false);
// We already checked the secondary weights, so don't do it again
skipSecCheck = true;
continue; // both advances
}
else
{
//
// The source's primary is ignorable, but the target's isn't. We treat
// ignorables as a secondary difference, so remember that we found one.
// BUT, for French secondary ordering we might have already found a secondary
// difference in the ignorables attached to this base char. If we have, we
// don't need to mark a difference here.
//
if ((!isFrenchSec &&
(result == Collator.EQUAL || strengthResult > Collator.SECONDARY)) ||
(isFrenchSec && !skipSecCheck))
{
strengthResult = Collator.SECONDARY;
result = Collator.GREATER;
}
// Skip to the next source element, but don't fetch another target element.
gett = false;
skipSecCheck = false;
continue;
}
}
else if (pTOrder == 0)
{
// record differences - see the comment above.
if ((!isFrenchSec &&
(result == Collator.EQUAL || strengthResult > Collator.SECONDARY)) ||
(isFrenchSec && !skipSecCheck))
{
result = Collator.LESS;
strengthResult = Collator.SECONDARY;
}
gets = false;
skipSecCheck = false;
continue;
}
//
// Neither of the orders is ignorable, and we already know that the primary
// orders are different because of the (pSOrder != pTOrder) test above.
// Record the difference and stop the comparison.
//
if (pSOrder < pTOrder)
result = Collator.LESS;
else
result = Collator.GREATER;
break;
}
else {
//
// The primary orders are the same, but we need to continue to check
// for secondary or tertiary differences.
//
result = checkSecTerDiff(sOrder, tOrder, result, skipSecCheck);
if (isFrenchSec &&
CollationElementIterator.isIgnorable(sOrder) &&
CollationElementIterator.isIgnorable(tOrder))
skipSecCheck = true;
else
skipSecCheck = false;
}
} // while()
if (sOrder != CollationElementIterator.NULLORDER) {
if (tOrder == CollationElementIterator.NULLORDER) {
// The source string hasn't not reached the end and target string has...
do {
if (CollationElementIterator.primaryOrder(sOrder) != 0) {
// We found a non-ignorable base character in the source string.
// This is a primary difference, so the source is greater
return 1;
} else if (CollationElementIterator.secondaryOrder(sOrder) != 0) {
//
// If the last character in the target string was a base character,
// or if we haven't found any secondary differences yet,
// we still need to look at accent marks in the source string, because
// they can affect the result in languages with reversed (French)
// secondary ordering.
//
if (!CollationElementIterator.isIgnorable(savedTOrder) ||
strengthResult > Collator.SECONDARY)
result = checkSecTerDiff(sOrder, 0, result, false);
else
continue;
}
} while ((sOrder = sourceCursor.next()) != CollationElementIterator.NULLORDER);
}
}
else if (tOrder != CollationElementIterator.NULLORDER) {
// See comments above.
do {
if (CollationElementIterator.primaryOrder(tOrder) != 0) {
return -1;
} else if (CollationElementIterator.secondaryOrder(tOrder) != 0) {
if (!CollationElementIterator.isIgnorable(savedSOrder) ||
strengthResult > Collator.SECONDARY)
result = checkSecTerDiff(0, tOrder, result, false);
else
continue;
}
} while ((tOrder = targetCursor.next()) != CollationElementIterator.NULLORDER);
}
// For IDENTICAL comparisons, we use a bitwise character comparison
// as a tiebreaker if all else is equal
if (result == 0 && getStrength() == IDENTICAL) {
result = DecompositionIterator.decompose(source,getDecomposition())
.compareTo(DecompositionIterator.decompose(target,getDecomposition()));
}
return result;
}
/**
* Transforms the string into a series of characters that can be compared
* with CollationKey.compareTo. This overrides java.text.Collator.getCollationKey.
* It can be overriden in a subclass.
*/
public CollationKey getCollationKey(String source)
{
//
// The basic algorithm here is to find all of the collation elements for each
// character in the source string, convert them to a char representation,
// and put them into the collation key. But it's trickier than that.
// Each collation element in a string has three components: primary (A vs B),
// secondary (A vs A-acute), and tertiary (A' vs a); and a primary difference
// at the end of a string takes precedence over a secondary or tertiary
// difference earlier in the string.
//
// To account for this, we put all of the primary orders at the beginning of the
// string, followed by the secondary and tertiary orders, separated by nulls.
//
// Here's a hypothetical example, with the collation element represented as
// a three-digit number, one digit for primary, one for secondary, etc.
//
// String: A a B Θ <--(e-acute)
// Collation Elements: 101 100 201 510
//
// Collation Key: 1125<null>0001<null>1010
//
// To make things even trickier, secondary differences (accent marks) are compared
// starting at the *end* of the string in languages with French secondary ordering.
// But when comparing the accent marks on a single base character, they are compared
// from the beginning. To handle this, we reverse all of the accents that belong
// to each base character, then we reverse the entire string of secondary orderings
// at the end. Taking the same example above, a French collator might return
// this instead:
//
// Collation Key: 1125<null>1000<null>1010
//
if (source == null)
return null;
primResult.setLength(0);
secResult.setLength(0);
terResult.setLength(0);
int order = 0;
boolean compareSec = (getStrength() >= Collator.SECONDARY);
boolean compareTer = (getStrength() >= Collator.TERTIARY);
int secOrder = CollationElementIterator.NULLORDER;
int terOrder = CollationElementIterator.NULLORDER;
int preSecIgnore = 0;
CollationElementIterator sourceCursor = new
CollationElementIterator(source, this);
// walk through each character
while ((order = sourceCursor.next()) !=
CollationElementIterator.NULLORDER)
{
secOrder = CollationElementIterator.secondaryOrder(order);
terOrder = CollationElementIterator.tertiaryOrder(order);
if (!CollationElementIterator.isIgnorable(order))
{
primResult.append((char) (CollationElementIterator.primaryOrder(order)
+ COLLATIONKEYOFFSET));
if (compareSec) {
//
// accumulate all of the ignorable/secondary characters attached
// to a given base character
//
if (isFrenchSec && preSecIgnore < secResult.length()) {
//
// We're doing reversed secondary ordering and we've hit a base
// (non-ignorable) character. Reverse any secondary orderings
// that applied to the last base character. (see block comment above.)
//
reverse(secResult, preSecIgnore, secResult.length());
}
// Remember where we are in the secondary orderings - this is how far
// back to go if we need to reverse them later.
secResult.append((char)(secOrder+ COLLATIONKEYOFFSET));
preSecIgnore = secResult.length();
}
if (compareTer) {
terResult.append((char)(terOrder+ COLLATIONKEYOFFSET));
}
}
else
{
if (compareSec && secOrder != 0)
secResult.append((char)
(secOrder+maxSecOrder+ COLLATIONKEYOFFSET));
if (compareTer && terOrder != 0)
terResult.append((char)
(terOrder+maxTerOrder+ COLLATIONKEYOFFSET));
}
}
if (isFrenchSec)
{
if (preSecIgnore < secResult.length()) {
// If we've accumlated any secondary characters after the last base character,
// reverse them.
reverse(secResult, preSecIgnore, secResult.length());
}
// And now reverse the entire secResult to get French secondary ordering.
reverse(secResult, 0, secResult.length());
}
primResult.append((char)0);
secResult.append((char)0);
secResult.append(terResult.toString());
primResult.append(secResult.toString());
if (getStrength() == IDENTICAL) {
primResult.append((char)0);
primResult.append(DecompositionIterator.decompose(source,getDecomposition()));
}
return new CollationKey(source, primResult.toString());
}
/**
* Standard override; no change in semantics.
*/
public Object clone() {
RuleBasedCollator other = (RuleBasedCollator) super.clone();
other.primResult = new StringBuffer(MAXTOKENLEN);
other.secResult = new StringBuffer(MAXTOKENLEN);
other.terResult = new StringBuffer(MAXTOKENLEN);
other.key = new StringBuffer(MAXKEYSIZE);
return other;
}
/**
* Compares the equality of two collation objects.
* @param obj the table-based collation object to be compared with this.
* @return true if the current table-based collation object is the same
* as the table-based collation object obj; false otherwise.
*/
public boolean equals(Object obj) {
if (obj == null) return false;
if (!super.equals(obj)) return false; // super does class check
RuleBasedCollator other = (RuleBasedCollator) obj;
// all other non-transient information is also contained in rules.
return (getRules().equals(other.getRules()));
}
/**
* Generates the hash code for the table-based collation object
*/
public int hashCode() {
return getRules().hashCode();
}
// ==============================================================
// private
// ==============================================================
/**
* Create a table-based collation object with the given rules.
* @see java.util.RuleBasedCollator#RuleBasedCollator
* @exception ParseException If the rules format is incorrect.
*/
private void build(String pattern) throws ParseException
{
int aStrength = Collator.IDENTICAL;
boolean isSource = true;
int i = 0;
String expChars;
String groupChars;
if (pattern.length() == 0)
throw new ParseException("Build rules empty.", 0);
// This array maps Unicode characters to their collation ordering
mapping = new CompactIntArray((int)UNMAPPED);
// Normalize the build rules. Find occurances of all decomposed characters
// and normalize the rules before feeding into the builder. By "normalize",
// we mean that all precomposed Unicode characters must be converted into
// a base character and one or more combining characters (such as accents).
// When there are multiple combining characters attached to a base character,
// the combining characters must be in their canonical order
//
pattern = DecompositionIterator.decompose(pattern, getDecomposition());
// Build the merged collation entries
// Since rules can be specified in any order in the string
// (e.g. "c , C < d , D < e , E .... C < CH")
// this splits all of the rules in the string out into separate
// objects and then sorts them. In the above example, it merges the
// "C < CH" rule in just before the "C < D" rule.
//
mPattern = new MergeCollation(pattern);
// Now walk though each entry and add it to my own tables
for (i = 0; i < mPattern.getCount(); ++i)
{
PatternEntry entry = mPattern.getItemAt(i);
if (entry != null) {
groupChars = entry.getChars();
if ((groupChars.length() > 1) &&
(groupChars.charAt(groupChars.length()-1) == '@')) {
isFrenchSec = true;
groupChars = groupChars.substring(0, groupChars.length()-1);
}
expChars = entry.getExtension();
if (expChars.length() != 0) {
addExpandOrder(groupChars, expChars, entry.getStrength());
} else if (groupChars.length() > 1) {
addContractOrder(groupChars, entry.getStrength());
lastChar = groupChars.charAt(0);
} else {
char ch = groupChars.charAt(0);
addOrder(ch, entry.getStrength());
lastChar = ch;
}
}
}
commit();
mapping.compact();
}
/**
* Look up for unmapped values in the expanded character table.
*/
private final void commit()
{
// When the expanding character tables are built by addExpandOrder,
// it doesn't know what the final ordering of each character
// in the expansion will be. Instead, it just puts the raw character
// code into the table, adding CHARINDEX as a flag. Now that we've
// finished building the mapping table, we can go back and look up
// that character to see what its real collation order is and
// stick that into the expansion table. That lets us avoid doing
// a two-stage lookup later.
if (expandTable != null)
{
for (int i = 0; i < expandTable.size(); i++)
{
int[] valueList = (int [])expandTable.elementAt(i);
for (int j = 0; j < valueList.length; j++)
{
if ((valueList[j] < EXPANDCHARINDEX) &&
(valueList[j] > CHARINDEX))
{
// found a expanding character
// the expanding char value is not filled in yet
char ch = (char)(valueList[j] - CHARINDEX);
// Get the real values for the non-filled entry
int realValue = mapping.elementAt(ch);
if (realValue == UNMAPPED)
{
// The real value is still unmapped, maybe it's an ignorable
// char
valueList[j] = IGNORABLEMASK & valueList[j-1];
}
else if (realValue >= CONTRACTCHARINDEX)
{
// if the entry is actually pointing to a contracting char
EntryPair pair = null;
Vector groupList = (Vector)
contractTable.elementAt(realValue
- CONTRACTCHARINDEX);
pair = (EntryPair)groupList.firstElement();
valueList[j] = pair.value;
}
else
{
// just fill in the value
valueList[j] = realValue;
}
}
}
}
}
}
/**
* Increment of the last order based on the comparison level.
*/
private final int increment(int aStrength, int lastValue)
{
switch(aStrength)
{
case Collator.PRIMARY:
// increment priamry order and mask off secondary and tertiary difference
lastValue += PRIMARYORDERINCREMENT;
lastValue &= PRIMARYORDERMASK;
isOverIgnore = true;
break;
case Collator.SECONDARY:
// increment secondary order and mask off tertiary difference
lastValue += SECONDARYORDERINCREMENT;
lastValue &= SECONDARYDIFFERENCEONLY;
// record max # of ignorable chars with secondary difference
if (!isOverIgnore)
maxSecOrder++;
break;
case Collator.TERTIARY:
// increment tertiary order
lastValue += TERTIARYORDERINCREMENT;
// record max # of ignorable chars with tertiary difference
if (!isOverIgnore)
maxTerOrder++;
break;
}
return lastValue;
}
/**
* Adds a character and its designated order into the collation table.
*/
private final void addOrder(char ch,
int aStrength)
{
// See if the char already has an order in the mapping table
int order = mapping.elementAt(ch);
if (order >= CONTRACTCHARINDEX) {
// There's already an entry for this character that points to a contracting
// character table. Instead of adding the character directly to the mapping
// table, we must add it to the contract table instead.
key.setLength(0);
key.append(ch);
addContractOrder(key.toString(), aStrength);
} else {
// add the entry to the mapping table,
// the same later entry replaces the previous one
currentOrder = increment(aStrength, currentOrder);
mapping.setElementAt(ch, currentOrder);
}
}
/**
* Adds the contracting string into the collation table.
*/
private final void addContractOrder(String groupChars,
int aStrength)
{
if (contractTable == null) {
contractTable = new Vector(INITIALTABLESIZE);
}
// Figure out what ordering to give this new entry
if (aStrength != IDENTICAL) {
currentOrder = increment(aStrength, currentOrder);
}
// See if the initial character of the string already has a contract table.
int entry = mapping.elementAt(groupChars.charAt(0));
Vector entryTable = getContractValues(entry - CONTRACTCHARINDEX);
if (entryTable != null) {
int index = getEntry(entryTable, groupChars);
if (index != UNMAPPED) {
// If there was already a contracting table for this character,
// we simply want to add (or replace) this string in it
EntryPair pair = (EntryPair) entryTable.elementAt(index);
pair.value = currentOrder;
} else {
entryTable.addElement(new EntryPair(groupChars, currentOrder));
}
}
else
{
// We need to create a new table of contract entries
entryTable = new Vector(INITIALTABLESIZE);
int tableIndex = CONTRACTCHARINDEX + contractTable.size();
// Always add the initial character's current ordering first.
entryTable.addElement(new EntryPair(groupChars.substring(0,1), entry));
// And add the new one
entryTable.addElement(new EntryPair(groupChars, currentOrder));
// Finally, add the new value table to the main contract table
// and update this character's mapping to point to it.
contractTable.addElement(entryTable);
mapping.setElementAt(groupChars.charAt(0), tableIndex);
}
}
private final int getEntry(Vector list, String name) {
for (int i = 0; i < list.size(); i++) {
EntryPair pair = (EntryPair)list.elementAt(i);
if (pair.entryName.equals(name)) {
return i;
}
}
return UNMAPPED;
}
/**
* Get the entry of hash table of the contracting string in the collation
* table.
* @param ch the starting character of the contracting string
*/
Vector getContractValues(char ch)
{
int index = mapping.elementAt(ch);
return getContractValues(index - CONTRACTCHARINDEX);
}
Vector getContractValues(int index)
{
if (index >= 0)
{
return (Vector)contractTable.elementAt(index);
}
else // not found
{
return null;
}
}
/**
* Adds the expanding string into the collation table.
*/
private final void addExpandOrder(String contractChars,
String expandChars,
int aStrength) throws ParseException
{
EntryPair pair = new EntryPair();
// Make a expanding char table if there's not one.
if (expandTable == null)
{
expandTable = new Vector(INITIALTABLESIZE);
}
// For expanding characters, what we stick into the main mapping table
// is the character's index in the expand table, plus a flag to indicate
// that it's an expanding character.
int tmpValue = EXPANDCHARINDEX + expandTable.size();
// need to check if the entry is key or not later
key.setLength(0);
int keyValue = UNMAPPED;
if (contractChars.length() > 1)
{
// This entry is actually a string of characters that contract
// and then expand back into a different string.
// First, we have to make sure that the entry is in the contract table
//
addContractOrder(contractChars, aStrength);
// Remember the character we just added, so that the code in build() can use it
// to decide where to put the next character.
lastChar = contractChars.charAt(0);
// Now that there's a contracting-table entry for this key, set its value
// to the expanding character sequence
Vector list = getContractValues(contractChars.charAt(0));
int entry = UNMAPPED;
entry = getEntry(list, contractChars);
if (entry != UNMAPPED) {
pair = (EntryPair)list.elementAt(entry);
// Remember what this entry's old value was, for use below.
keyValue = pair.value;
}
pair.entryName = contractChars;
pair.value = tmpValue;
}
else
{
// There's no contraction involved, just a single character expanding
// into several other characters.
char ch = contractChars.charAt(0);
if ((keyValue = mapping.elementAt(ch)) == UNMAPPED) {
// This character doesn't have an entry in the mapping table yet,
// so make one for it.
addOrder(ch, aStrength);
lastChar = ch;
// Remember the ordering that we just created for this character...
keyValue = mapping.elementAt(lastChar);
} else {
// This character already had an ordering, which we don't want to disturb,
// so create a new one to use.
keyValue = increment(aStrength, mapping.elementAt(lastChar));
}
mapping.setElementAt(ch, tmpValue);
}
// Create a list of the collation orders that this expands into...
int[] valueList = new int[expandChars.length()+1];
valueList[0] = keyValue;
for (int i = 0; i < expandChars.length(); i++)
{
int mapValue = mapping.elementAt(expandChars.charAt(i));
if (mapValue >= CONTRACTCHARINDEX)
{
// if the expanding char is also a contracting char, look up the value
key.append(expandChars.charAt(i));
int foundValue = CHARINDEX + expandChars.charAt(i);
Vector list = getContractValues(expandChars.charAt(i));
if (list != null) {
int entry = UNMAPPED;
entry = getEntry(list, key.toString());
if (entry != UNMAPPED) {
pair = (EntryPair)list.elementAt(entry);
foundValue = pair.value;
}
}
key.setLength(0);
valueList[i+1] = foundValue;
}
else if (mapValue != UNMAPPED)
{
// can't find it in the table, will be filled in by commit().
valueList[i+1] = mapValue;
}
else
{
valueList[i+1] = CHARINDEX + (int)(expandChars.charAt(i));
}
}
// Add the expanding char list into the table, finally.
expandTable.addElement(valueList);
}
/**
* Get the entry of hash table of the expanding string in the collation
* table.
* @param ch the starting character of the expanding string
*/
final int[] getExpandValueList(char ch)
{
int expIndex = mapping.elementAt(ch);
if ((expIndex >= EXPANDCHARINDEX) &&
(expIndex < CONTRACTCHARINDEX))
{
int tmpIndex = expIndex - EXPANDCHARINDEX;
return (int[])expandTable.elementAt(tmpIndex);
}
else
{
return null;
}
}
/**
* Get the entry of hash table of the expanding string in the collation
* table.
* @param idx the index of the expanding string value list
*/
final int[] getExpandValueList(int idx)
{
if (idx < expandTable.size())
{
return (int[])expandTable.elementAt(idx);
}
else
{
return null;
}
}
/**
* Get the comarison order of a character from the collation table.
* @return the comparison order of a character.
*/
final int getUnicodeOrder(char ch)
{
return mapping.elementAt(ch);
}
/**
* Check for the secondary and tertiary differences of source and
* target comparison orders.
* @return Collator.LESS if sOrder < tOrder; EQUAL if sOrder == tOrder;
* Collator.GREATER if sOrder > tOrder.
*/
private final int checkSecTerDiff(int sOrder,
int tOrder,
int result,
boolean skipSecCheck)
{
int endResult = result;
if (CollationElementIterator.secondaryOrder(sOrder) !=
CollationElementIterator.secondaryOrder(tOrder))
{
if ((!isFrenchSec &&
(result == Collator.EQUAL || strengthResult > Collator.SECONDARY)) ||
(isFrenchSec && !skipSecCheck))
{
strengthResult = Collator.SECONDARY;
if (CollationElementIterator.secondaryOrder(sOrder) <
CollationElementIterator.secondaryOrder(tOrder))
endResult = Collator.LESS;
else
endResult = Collator.GREATER;
}
}
else if ((CollationElementIterator.tertiaryOrder(sOrder) !=
CollationElementIterator.tertiaryOrder(tOrder)) &&
(endResult == Collator.EQUAL))
{
strengthResult = Collator.TERTIARY;
if (CollationElementIterator.tertiaryOrder(sOrder) <
CollationElementIterator.tertiaryOrder(tOrder))
endResult = Collator.LESS;
else
endResult = Collator.GREATER;
}
return endResult;
}
/**
* Reverse a string.
*/
private final void reverse (StringBuffer result, int from, int to)
{
int i = from;
char swap;
int j = to - 1;
while (i < j) {
swap = result.charAt(i);
result.setCharAt(i, result.charAt(j));
result.setCharAt(j, swap);
i++;
j--;
}
}
// Proclaim compatibility with 1.1
static final long serialVersionUID = 2822366911447564107L;
static int CHARINDEX = 0x70000000; // need look up in .commit()
static int EXPANDCHARINDEX = 0x7E000000; // Expand index follows
static int CONTRACTCHARINDEX = 0x7F000000; // contract indexes follow
static int UNMAPPED = 0xFFFFFFFF;
private final static int SHORT_MAX_VALUE = 32767;
private final static int PRIMARYORDERINCREMENT = 0x00010000;
private final static int MAXIGNORABLE = 0x00010000;
private final static int SECONDARYORDERINCREMENT = 0x00000100;
private final static int TERTIARYORDERINCREMENT = 0x00000001;
final static int PRIMARYORDERMASK = 0xffff0000;
final static int SECONDARYORDERMASK = 0x0000ff00;
final static int TERTIARYORDERMASK = 0x000000ff;
final static int PRIMARYDIFFERENCEONLY = 0xffff0000;
final static int SECONDARYDIFFERENCEONLY = 0xffffff00;
private final static int SECONDARYRESETMASK = 0x0000ffff;
private final static int IGNORABLEMASK = 0x0000ffff;
private final static int INITIALTABLESIZE = 20;
private final static int MAXKEYSIZE = 5;
static int PRIMARYORDERSHIFT = 16;
static int SECONDARYORDERSHIFT = 8;
private final static int MAXTOKENLEN = 256;
private final static int MAXRULELEN = 512;
private final static int COLLATIONKEYOFFSET = 1;
// these data members are reconstructed by readObject()
private boolean isFrenchSec = false;
private String ruleTable = null;
private CompactIntArray mapping = null;
private Vector contractTable = null;
private Vector expandTable = null;
// transients, only used in build or processing
private transient MergeCollation mPattern = null;
private transient boolean isOverIgnore = false;
private transient int currentOrder = 0;
private transient short maxSecOrder = 0;
private transient short maxTerOrder = 0;
private transient char lastChar;
private transient StringBuffer key = new StringBuffer(MAXKEYSIZE);
private transient int strengthResult = Collator.IDENTICAL;
private transient StringBuffer primResult = new StringBuffer(MAXTOKENLEN);
private transient StringBuffer secResult = new StringBuffer(MAXTOKENLEN);
private transient StringBuffer terResult = new StringBuffer(MAXTOKENLEN);
}