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/*
*******************************************************************************
* Copyright (C) 2007-2012, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.text;
import java.io.Serializable;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import com.ibm.icu.impl.PatternProps;
import com.ibm.icu.impl.PluralRulesLoader;
import com.ibm.icu.impl.Utility;
import com.ibm.icu.util.Output;
import com.ibm.icu.util.ULocale;
/**
* Defines rules for mapping non-negative numeric values onto a small set of
* keywords.
*
*
Rules are constructed from a text description, consisting
* of a series of keywords and conditions. The {@link #select} method
* examines each condition in order and returns the keyword for the
* first condition that matches the number. If none match,
* {@link #KEYWORD_OTHER} is returned.
*
* A PluralRules object is immutable.
* It contains caches for sample values, but those are synchronized.
*
*
PluralRules is Serializable so that it can be used in formatters, which are
* serializable.
*
*
For more information, details, and tips for writing rules, see the
* LDML spec,
* C.11 Language Plural Rules
*
*
* Examples:
* "one: n is 1; few: n in 2..4"
*
* This defines two rules, for 'one' and 'few'. The condition for
* 'one' is "n is 1" which means that the number must be equal to
* 1 for this condition to pass. The condition for 'few' is
* "n in 2..4" which means that the number must be between 2 and
* 4 inclusive - and be an integer - for this condition to pass. All other
* numbers are assigned the keyword "other" by the default rule.
*
* "zero: n is 0; one: n is 1; zero: n mod 100 in 1..19"
* This illustrates that the same keyword can be defined multiple times.
* Each rule is examined in order, and the first keyword whose condition
* passes is the one returned. Also notes that a modulus is applied
* to n in the last rule. Thus its condition holds for 119, 219, 319...
*
* "one: n is 1; few: n mod 10 in 2..4 and n mod 100 not in 12..14"
*
* This illustrates conjunction and negation. The condition for 'few'
* has two parts, both of which must be met: "n mod 10 in 2..4" and
* "n mod 100 not in 12..14". The first part applies a modulus to n
* before the test as in the previous example. The second part applies
* a different modulus and also uses negation, thus it matches all
* numbers _not_ in 12, 13, 14, 112, 113, 114, 212, 213, 214...
*
* Syntax:
* rules = rule (';' rule)*
* rule = keyword ':' condition
* keyword = <identifier>
* condition = and_condition ('or' and_condition)*
* and_condition = relation ('and' relation)*
* relation = is_relation | in_relation | within_relation | 'n'
* is_relation = expr 'is' ('not')? value
* in_relation = expr ('not')? 'in' range_list
* within_relation = expr ('not')? 'within' range_list
* expr = 'n' ('mod' value)?
* range_list = (range | value) (',' range_list)*
* value = digit+
* digit = 0|1|2|3|4|5|6|7|8|9
* range = value'..'value
*
*
* An "identifier" is a sequence of characters that do not have the
* Unicode Pattern_Syntax or Pattern_White_Space properties.
*
* The difference between 'in' and 'within' is that 'in' only includes
* integers in the specified range, while 'within' includes all values.
* Using 'within' with a range_list consisting entirely of values
* is the same as using 'in' (it's not an error).
* @stable ICU 3.8
*/
public class PluralRules implements Serializable {
private static final long serialVersionUID = 1;
private final RuleList rules;
private final Set keywords;
private int repeatLimit; // for equality test
private transient int hashCode;
private transient Map> _keySamplesMap;
private transient Map _keyLimitedMap;
// Standard keywords.
/**
* Common name for the 'zero' plural form.
* @stable ICU 3.8
*/
public static final String KEYWORD_ZERO = "zero";
/**
* Common name for the 'singular' plural form.
* @stable ICU 3.8
*/
public static final String KEYWORD_ONE = "one";
/**
* Common name for the 'dual' plural form.
* @stable ICU 3.8
*/
public static final String KEYWORD_TWO = "two";
/**
* Common name for the 'paucal' or other special plural form.
* @stable ICU 3.8
*/
public static final String KEYWORD_FEW = "few";
/**
* Common name for the arabic (11 to 99) plural form.
* @stable ICU 3.8
*/
public static final String KEYWORD_MANY = "many";
/**
* Common name for the default plural form. This name is returned
* for values to which no other form in the rule applies. It
* can additionally be assigned rules of its own.
* @stable ICU 3.8
*/
public static final String KEYWORD_OTHER = "other";
/**
* Value returned by {@link #getUniqueKeywordValue} when there is no
* unique value to return.
* @stable ICU 4.8
*/
public static final double NO_UNIQUE_VALUE = -0.00123456777;
/**
* Type of plurals and PluralRules.
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
public enum PluralType {
/**
* Plural rules for cardinal numbers: 1 file vs. 2 files.
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
CARDINAL,
/**
* Plural rules for ordinal numbers: 1st file, 2nd file, 3rd file, 4th file, etc.
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
ORDINAL
};
/*
* The default constraint that is always satisfied.
*/
private static final Constraint NO_CONSTRAINT = new Constraint() {
private static final long serialVersionUID = 9163464945387899416L;
public boolean isFulfilled(double n) {
return true;
}
public boolean isLimited() {
return false;
}
public String toString() {
return "n is any";
}
public int updateRepeatLimit(int limit) {
return limit;
}
};
/*
* The default rule that always returns "other".
*/
private static final Rule DEFAULT_RULE = new Rule() {
private static final long serialVersionUID = -5677499073940822149L;
public String getKeyword() {
return KEYWORD_OTHER;
}
public boolean appliesTo(double n) {
return true;
}
public boolean isLimited() {
return false;
}
public String toString() {
return "(" + KEYWORD_OTHER + ")";
}
public int updateRepeatLimit(int limit) {
return limit;
}
};
/**
* The default rules that accept any number and return
* {@link #KEYWORD_OTHER}.
* @stable ICU 3.8
*/
public static final PluralRules DEFAULT =
new PluralRules(new RuleChain(DEFAULT_RULE));
/**
* Parses a plural rules description and returns a PluralRules.
* @param description the rule description.
* @throws ParseException if the description cannot be parsed.
* The exception index is typically not set, it will be -1.
* @stable ICU 3.8
*/
public static PluralRules parseDescription(String description)
throws ParseException {
description = description.trim();
if (description.length() == 0) {
return DEFAULT;
}
return new PluralRules(parseRuleChain(description));
}
/**
* Creates a PluralRules from a description if it is parsable,
* otherwise returns null.
* @param description the rule description.
* @return the PluralRules
* @stable ICU 3.8
*/
public static PluralRules createRules(String description) {
try {
return parseDescription(description);
} catch(ParseException e) {
return null;
}
}
/*
* A constraint on a number.
*/
private interface Constraint extends Serializable {
/*
* Returns true if the number fulfills the constraint.
* @param n the number to test, >= 0.
*/
boolean isFulfilled(double n);
/*
* Returns false if an unlimited number of values fulfills the
* constraint.
*/
boolean isLimited();
/*
* Returns the larger of limit or the limit of this constraint.
* If the constraint is a simple range test, this is the higher
* end of the range; if it is a modulo test, this is the modulus.
*
* @param limit the target limit
* @return the new limit
*/
int updateRepeatLimit(int limit);
}
/*
* A pluralization rule.
*/
private interface Rule extends Serializable {
/* Returns the keyword that names this rule. */
String getKeyword();
/* Returns true if the rule applies to the number. */
boolean appliesTo(double n);
/* Returns false if an unlimited number of values generate this rule. */
boolean isLimited();
/* Returns the larger of limit and this rule's limit. */
int updateRepeatLimit(int limit);
}
/*
* A list of rules to apply in order.
*/
private interface RuleList extends Serializable {
/* Returns the keyword of the first rule that applies to the number. */
String select(double n);
/* Returns the set of defined keywords. */
Set getKeywords();
/* Return the value at which this rulelist starts repeating. */
int getRepeatLimit();
/* Return true if the values for this keyword are limited. */
boolean isLimited(String keyword);
}
/*
* syntax:
* condition : or_condition
* and_condition
* or_condition : and_condition 'or' condition
* and_condition : relation
* relation 'and' relation
* relation : is_relation
* in_relation
* within_relation
* 'n' EOL
* is_relation : expr 'is' value
* expr 'is' 'not' value
* in_relation : expr 'in' range
* expr 'not' 'in' range
* within_relation : expr 'within' range
* expr 'not' 'within' range
* expr : 'n'
* 'n' 'mod' value
* value : digit+
* digit : 0|1|2|3|4|5|6|7|8|9
* range : value'..'value
*/
private static Constraint parseConstraint(String description)
throws ParseException {
description = description.trim().toLowerCase(Locale.ENGLISH);
Constraint result = null;
String[] or_together = Utility.splitString(description, "or");
for (int i = 0; i < or_together.length; ++i) {
Constraint andConstraint = null;
String[] and_together = Utility.splitString(or_together[i], "and");
for (int j = 0; j < and_together.length; ++j) {
Constraint newConstraint = NO_CONSTRAINT;
String condition = and_together[j].trim();
String[] tokens = Utility.splitWhitespace(condition);
int mod = 0;
boolean inRange = true;
boolean integersOnly = true;
long lowBound = Long.MAX_VALUE;
long highBound = Long.MIN_VALUE;
long[] vals = null;
boolean isRange = false;
int x = 0;
String t = tokens[x++];
if (!"n".equals(t)) {
throw unexpected(t, condition);
}
if (x < tokens.length) {
t = tokens[x++];
if ("mod".equals(t)) {
mod = Integer.parseInt(tokens[x++]);
t = nextToken(tokens, x++, condition);
}
if ("is".equals(t)) {
t = nextToken(tokens, x++, condition);
if ("not".equals(t)) {
inRange = false;
t = nextToken(tokens, x++, condition);
}
} else {
isRange = true;
if ("not".equals(t)) {
inRange = false;
t = nextToken(tokens, x++, condition);
}
if ("in".equals(t)) {
t = nextToken(tokens, x++, condition);
} else if ("within".equals(t)) {
integersOnly = false;
t = nextToken(tokens, x++, condition);
} else {
throw unexpected(t, condition);
}
}
if (isRange) {
String[] range_list = Utility.splitString(t, ",");
vals = new long[range_list.length * 2];
for (int k1 = 0, k2 = 0; k1 < range_list.length; ++k1, k2 += 2) {
String range = range_list[k1];
String[] pair = Utility.splitString(range, "..");
long low, high;
if (pair.length == 2) {
low = Long.parseLong(pair[0]);
high = Long.parseLong(pair[1]);
if (low > high) {
throw unexpected(range, condition);
}
} else if (pair.length == 1) {
low = high = Long.parseLong(pair[0]);
} else {
throw unexpected(range, condition);
}
vals[k2] = low;
vals[k2+1] = high;
lowBound = Math.min(lowBound, low);
highBound = Math.max(highBound, high);
}
if (vals.length == 2) {
vals = null;
}
} else {
lowBound = highBound = Long.parseLong(t);
}
if (x != tokens.length) {
throw unexpected(tokens[x], condition);
}
newConstraint =
new RangeConstraint(mod, inRange, integersOnly, lowBound, highBound, vals);
}
if (andConstraint == null) {
andConstraint = newConstraint;
} else {
andConstraint = new AndConstraint(andConstraint,
newConstraint);
}
}
if (result == null) {
result = andConstraint;
} else {
result = new OrConstraint(result, andConstraint);
}
}
return result;
}
/* Returns a parse exception wrapping the token and context strings. */
private static ParseException unexpected(String token, String context) {
return new ParseException("unexpected token '" + token +
"' in '" + context + "'", -1);
}
/*
* Returns the token at x if available, else throws a parse exception.
*/
private static String nextToken(String[] tokens, int x, String context)
throws ParseException {
if (x < tokens.length) {
return tokens[x];
}
throw new ParseException("missing token at end of '" + context + "'", -1);
}
/*
* Syntax:
* rule : keyword ':' condition
* keyword:
*/
private static Rule parseRule(String description) throws ParseException {
int x = description.indexOf(':');
if (x == -1) {
throw new ParseException("missing ':' in rule description '" +
description + "'", 0);
}
String keyword = description.substring(0, x).trim();
if (!isValidKeyword(keyword)) {
throw new ParseException("keyword '" + keyword +
" is not valid", 0);
}
description = description.substring(x+1).trim();
if (description.length() == 0) {
throw new ParseException("missing constraint in '" +
description + "'", x+1);
}
Constraint constraint = parseConstraint(description);
Rule rule = new ConstrainedRule(keyword, constraint);
return rule;
}
/*
* Syntax:
* rules : rule
* rule ';' rules
*/
private static RuleChain parseRuleChain(String description)
throws ParseException {
RuleChain rc = null;
String[] rules = Utility.split(description, ';');
for (int i = 0; i < rules.length; ++i) {
Rule r = parseRule(rules[i].trim());
if (rc == null) {
rc = new RuleChain(r);
} else {
rc = rc.addRule(r);
}
}
return rc;
}
/*
* An implementation of Constraint representing a modulus,
* a range of values, and include/exclude. Provides lots of
* convenience factory methods.
*/
private static class RangeConstraint implements Constraint, Serializable {
private static final long serialVersionUID = 1;
private int mod;
private boolean inRange;
private boolean integersOnly;
private long lowerBound;
private long upperBound;
private long[] range_list;
RangeConstraint(int mod, boolean inRange, boolean integersOnly,
long lowerBound, long upperBound, long[] range_list) {
this.mod = mod;
this.inRange = inRange;
this.integersOnly = integersOnly;
this.lowerBound = lowerBound;
this.upperBound = upperBound;
this.range_list = range_list;
}
public boolean isFulfilled(double n) {
if (integersOnly && (n - (long)n) != 0.0) {
return !inRange;
}
if (mod != 0) {
n = n % mod; // java % handles double numerator the way we want
}
boolean test = n >= lowerBound && n <= upperBound;
if (test && range_list != null) {
test = false;
for (int i = 0; !test && i < range_list.length; i += 2) {
test = n >= range_list[i] && n <= range_list[i+1];
}
}
return inRange == test;
}
public boolean isLimited() {
return integersOnly && inRange && mod == 0;
}
public int updateRepeatLimit(int limit) {
int mylimit = mod == 0 ? (int)upperBound : mod;
return Math.max(mylimit, limit);
}
public String toString() {
class ListBuilder {
StringBuilder sb = new StringBuilder("[");
ListBuilder add(String s) {
return add(s, null);
}
ListBuilder add(String s, Object o) {
if (sb.length() > 1) {
sb.append(", ");
}
sb.append(s);
if (o != null) {
sb.append(": ").append(o.toString());
}
return this;
}
public String toString() {
String s = sb.append(']').toString();
sb = null;
return s;
}
}
ListBuilder lb = new ListBuilder();
if (mod > 1) {
lb.add("mod", mod);
}
if (inRange) {
lb.add("in");
} else {
lb.add("except");
}
if (integersOnly) {
lb.add("ints");
}
if (lowerBound == upperBound) {
lb.add(String.valueOf(lowerBound));
} else {
lb.add(String.valueOf(lowerBound) + "-" + String.valueOf(upperBound));
}
if (range_list != null) {
lb.add(Arrays.toString(range_list));
}
return lb.toString();
}
}
/* Convenience base class for and/or constraints. */
private static abstract class BinaryConstraint implements Constraint,
Serializable {
private static final long serialVersionUID = 1;
protected final Constraint a;
protected final Constraint b;
private final String conjunction;
protected BinaryConstraint(Constraint a, Constraint b, String c) {
this.a = a;
this.b = b;
this.conjunction = c;
}
public int updateRepeatLimit(int limit) {
return a.updateRepeatLimit(b.updateRepeatLimit(limit));
}
public String toString() {
return a.toString() + conjunction + b.toString();
}
}
/* A constraint representing the logical and of two constraints. */
private static class AndConstraint extends BinaryConstraint {
private static final long serialVersionUID = 7766999779862263523L;
AndConstraint(Constraint a, Constraint b) {
super(a, b, " && ");
}
public boolean isFulfilled(double n) {
return a.isFulfilled(n) && b.isFulfilled(n);
}
public boolean isLimited() {
// we ignore the case where both a and b are unlimited but no values
// satisfy both-- we still consider this 'unlimited'
return a.isLimited() || b.isLimited();
}
}
/* A constraint representing the logical or of two constraints. */
private static class OrConstraint extends BinaryConstraint {
private static final long serialVersionUID = 1405488568664762222L;
OrConstraint(Constraint a, Constraint b) {
super(a, b, " || ");
}
public boolean isFulfilled(double n) {
return a.isFulfilled(n) || b.isFulfilled(n);
}
public boolean isLimited() {
return a.isLimited() && b.isLimited();
}
}
/*
* Implementation of Rule that uses a constraint.
* Provides 'and' and 'or' to combine constraints. Immutable.
*/
private static class ConstrainedRule implements Rule, Serializable {
private static final long serialVersionUID = 1;
private final String keyword;
private final Constraint constraint;
public ConstrainedRule(String keyword, Constraint constraint) {
this.keyword = keyword;
this.constraint = constraint;
}
@SuppressWarnings("unused")
public Rule and(Constraint c) {
return new ConstrainedRule(keyword, new AndConstraint(constraint, c));
}
@SuppressWarnings("unused")
public Rule or(Constraint c) {
return new ConstrainedRule(keyword, new OrConstraint(constraint, c));
}
public String getKeyword() {
return keyword;
}
public boolean appliesTo(double n) {
return constraint.isFulfilled(n);
}
public int updateRepeatLimit(int limit) {
return constraint.updateRepeatLimit(limit);
}
public boolean isLimited() {
return constraint.isLimited();
}
public String toString() {
return keyword + ": " + constraint;
}
}
/*
* Implementation of RuleList that is itself a node in a linked list.
* Immutable, but supports chaining with 'addRule'.
*/
private static class RuleChain implements RuleList, Serializable {
private static final long serialVersionUID = 1;
private final Rule rule;
private final RuleChain next;
/** Creates a rule chain with the single rule. */
public RuleChain(Rule rule) {
this(rule, null);
}
private RuleChain(Rule rule, RuleChain next) {
this.rule = rule;
this.next = next;
}
public RuleChain addRule(Rule nextRule) {
return new RuleChain(nextRule, this);
}
private Rule selectRule(double n) {
Rule r = null;
if (next != null) {
r = next.selectRule(n);
}
if (r == null && rule.appliesTo(n)) {
r = rule;
}
return r;
}
public String select(double n) {
Rule r = selectRule(n);
if (r == null) {
return KEYWORD_OTHER;
}
return r.getKeyword();
}
public Set getKeywords() {
Set result = new HashSet();
result.add(KEYWORD_OTHER);
RuleChain rc = this;
while (rc != null) {
result.add(rc.rule.getKeyword());
rc = rc.next;
}
return result;
}
public boolean isLimited(String keyword) {
// if all rules with this keyword are limited, it's limited,
// and if there's no rule with this keyword, it's unlimited
RuleChain rc = this;
boolean result = false;
while (rc != null) {
if (keyword.equals(rc.rule.getKeyword())) {
if (!rc.rule.isLimited()) {
return false;
}
result = true;
}
rc = rc.next;
}
return result;
}
public int getRepeatLimit() {
int result = 0;
RuleChain rc = this;
while (rc != null) {
result = rc.rule.updateRepeatLimit(result);
rc = rc.next;
}
return result;
}
public String toString() {
String s = rule.toString();
if (next != null) {
s = next.toString() + "; " + s;
}
return s;
}
}
// -------------------------------------------------------------------------
// Static class methods.
// -------------------------------------------------------------------------
/**
* Provides access to the predefined cardinal-number PluralRules for a given
* locale.
* Same as forLocale(locale, PluralType.CARDINAL).
*
* ICU defines plural rules for many locales based on CLDR Language Plural Rules.
* For these predefined rules, see CLDR page at
* http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
*
* @param locale The locale for which a PluralRules object is
* returned.
* @return The predefined PluralRules object for this locale.
* If there's no predefined rules for this locale, the rules
* for the closest parent in the locale hierarchy that has one will
* be returned. The final fallback always returns the default
* rules.
* @stable ICU 3.8
*/
public static PluralRules forLocale(ULocale locale) {
return PluralRulesLoader.loader.forLocale(locale, PluralType.CARDINAL);
}
/**
* Provides access to the predefined PluralRules for a given
* locale and the plural type.
*
*
ICU defines plural rules for many locales based on CLDR Language Plural Rules.
* For these predefined rules, see CLDR page at
* http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
*
* @param locale The locale for which a PluralRules object is
* returned.
* @param type The plural type (e.g., cardinal or ordinal).
* @return The predefined PluralRules object for this locale.
* If there's no predefined rules for this locale, the rules
* for the closest parent in the locale hierarchy that has one will
* be returned. The final fallback always returns the default
* rules.
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
public static PluralRules forLocale(ULocale locale, PluralType type) {
return PluralRulesLoader.loader.forLocale(locale, type);
}
/*
* Checks whether a token is a valid keyword.
*
* @param token the token to be checked
* @return true if the token is a valid keyword.
*/
private static boolean isValidKeyword(String token) {
return PatternProps.isIdentifier(token);
}
/*
* Creates a new PluralRules object. Immutable.
*/
private PluralRules(RuleList rules) {
this.rules = rules;
this.keywords = Collections.unmodifiableSet(rules.getKeywords());
}
/**
* Given a number, returns the keyword of the first rule that applies to
* the number.
*
* @param number The number for which the rule has to be determined.
* @return The keyword of the selected rule.
* @stable ICU 4.0
*/
public String select(double number) {
return rules.select(number);
}
/**
* Returns a set of all rule keywords used in this PluralRules
* object. The rule "other" is always present by default.
*
* @return The set of keywords.
* @stable ICU 3.8
*/
public Set getKeywords() {
return keywords;
}
/**
* Returns the unique value that this keyword matches, or {@link #NO_UNIQUE_VALUE}
* if the keyword matches multiple values or is not defined for this PluralRules.
*
* @param keyword the keyword to check for a unique value
* @return The unique value for the keyword, or NO_UNIQUE_VALUE.
* @stable ICU 4.8
*/
public double getUniqueKeywordValue(String keyword) {
Collection values = getAllKeywordValues(keyword);
if (values != null && values.size() == 1) {
return values.iterator().next();
}
return NO_UNIQUE_VALUE;
}
/**
* Returns all the values that trigger this keyword, or null if the number of such
* values is unlimited.
*
* @param keyword the keyword
* @return the values that trigger this keyword, or null. The returned collection
* is immutable. It will be empty if the keyword is not defined.
* @stable ICU 4.8
*/
public Collection getAllKeywordValues(String keyword) {
// HACK for now
if (!keywords.contains(keyword)) {
return Collections.emptyList();
}
Collection result = getKeySamplesMap().get(keyword);
// We depend on MAX_SAMPLES here. It's possible for a conjunction
// of unlimited rules that 'looks' unlimited to return a limited
// number of values. There's no bounds to this limited number, in
// general, because you can construct arbitrarily complex rules. Since
// we always generate 3 samples if a rule is really unlimited, that's
// where we put the cutoff.
if (result.size() > 2 && !getKeyLimitedMap().get(keyword)) {
return null;
}
return result;
}
/**
* Returns a list of values for which select() would return that keyword,
* or null if the keyword is not defined. The returned collection is unmodifiable.
* The returned list is not complete, and there might be additional values that
* would return the keyword.
*
* @param keyword the keyword to test
* @return a list of values matching the keyword.
* @stable ICU 4.8
*/
public Collection getSamples(String keyword) {
if (!keywords.contains(keyword)) {
return null;
}
return getKeySamplesMap().get(keyword);
}
private Map getKeyLimitedMap() {
initKeyMaps();
return _keyLimitedMap;
}
private Map> getKeySamplesMap() {
initKeyMaps();
return _keySamplesMap;
}
private synchronized void initKeyMaps() {
// ensure both _keySamplesMap and _keyLimitedMap are initialized.
if (_keySamplesMap == null) {
// If this were allowed to vary on a per-call basis, we'd have to recheck and
// possibly rebuild the samples cache. Doesn't seem worth it.
// This 'max samples' value only applies to keywords that are unlimited, for
// other keywords all the matching values are returned. This might be a lot.
final int MAX_SAMPLES = 3;
Map temp = new HashMap();
for (String k : keywords) {
temp.put(k, rules.isLimited(k));
}
_keyLimitedMap = temp;
Map> sampleMap = new HashMap>();
int keywordsRemaining = keywords.size();
int limit = Math.max(5, getRepeatLimit() * MAX_SAMPLES) * 2;
for (int i = 0; keywordsRemaining > 0 && i < limit; ++i) {
double val = i / 2.0;
String keyword = select(val);
boolean keyIsLimited = _keyLimitedMap.get(keyword);
List list = sampleMap.get(keyword);
if (list == null) {
list = new ArrayList(MAX_SAMPLES);
sampleMap.put(keyword, list);
} else if (!keyIsLimited && list.size() == MAX_SAMPLES) {
continue;
}
list.add(Double.valueOf(val));
if (!keyIsLimited && list.size() == MAX_SAMPLES) {
--keywordsRemaining;
}
}
if (keywordsRemaining > 0) {
for (String k : keywords) {
if (!sampleMap.containsKey(k)) {
sampleMap.put(k, Collections.emptyList());
if (--keywordsRemaining == 0) {
break;
}
}
}
}
// Make lists immutable so we can return them directly
for (Entry> entry : sampleMap.entrySet()) {
sampleMap.put(entry.getKey(), Collections.unmodifiableList(entry.getValue()));
}
_keySamplesMap = sampleMap;
}
}
/**
* Returns the set of locales for which PluralRules are known.
* @return the set of locales for which PluralRules are known, as a list
* @draft ICU 4.2
* @provisional This API might change or be removed in a future release.
*/
public static ULocale[] getAvailableULocales() {
return PluralRulesLoader.loader.getAvailableULocales();
}
/**
* Returns the 'functionally equivalent' locale with respect to
* plural rules. Calling PluralRules.forLocale with the functionally equivalent
* locale, and with the provided locale, returns rules that behave the same.
*
* All locales with the same functionally equivalent locale have
* plural rules that behave the same. This is not exaustive;
* there may be other locales whose plural rules behave the same
* that do not have the same equivalent locale.
*
* @param locale the locale to check
* @param isAvailable if not null and of length > 0, this will hold 'true' at
* index 0 if locale is directly defined (without fallback) as having plural rules
* @return the functionally-equivalent locale
* @draft ICU 4.2
* @provisional This API might change or be removed in a future release.
*/
public static ULocale getFunctionalEquivalent(ULocale locale, boolean[] isAvailable) {
return PluralRulesLoader.loader.getFunctionalEquivalent(locale, isAvailable);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
public String toString() {
return "keywords: " + keywords +
" limit: " + getRepeatLimit() +
" rules: " + rules.toString();
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
public int hashCode() {
if (hashCode == 0) {
// cache it
int newHashCode = keywords.hashCode();
for (int i = 0; i < 12; ++i) {
newHashCode = newHashCode * 31 + select(i).hashCode();
}
if (newHashCode == 0) {
newHashCode = 1;
}
hashCode = newHashCode;
}
return hashCode;
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
public boolean equals(Object rhs) {
return rhs instanceof PluralRules && equals((PluralRules)rhs);
}
/**
* Returns true if rhs is equal to this.
* @param rhs the PluralRules to compare to.
* @return true if this and rhs are equal.
* @stable ICU 3.8
*/
public boolean equals(PluralRules rhs) {
if (rhs == null) {
return false;
}
if (rhs == this) {
return true;
}
if (hashCode() != rhs.hashCode()) {
return false;
}
if (!rhs.getKeywords().equals(keywords)) {
return false;
}
int limit = Math.max(getRepeatLimit(), rhs.getRepeatLimit());
for (int i = 0; i < limit * 2; ++i) {
if (!select(i).equals(rhs.select(i))) {
return false;
}
}
return true;
}
private int getRepeatLimit() {
if (repeatLimit == 0) {
repeatLimit = rules.getRepeatLimit() + 1;
}
return repeatLimit;
}
/**
* Status of the keyword for the rules, given a set of explicit values.
*
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
public enum KeywordStatus {
/**
* The keyword is not valid for the rules.
*
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
INVALID,
/**
* The keyword is valid, but unused (it is covered by the explicit values).
*
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
SUPPRESSED,
/**
* The keyword is valid, used, and has a single possible value (before considering explicit values).
*
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
UNIQUE,
/**
* The keyword is valid, used, not unique, and has a finite set of values.
*
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
BOUNDED,
/**
* The keyword is valid but not bounded; there indefinitely many matching values.
*
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
UNBOUNDED
}
/**
* Find the status for the keyword, given a certain set of explicit values.
*
* @param keyword
* the particular keyword (call rules.getKeywords() to get the valid ones)
* @param offset
* the offset used, or 0.0d if not. Internally, the offset is subtracted from each explicit value before
* checking against the keyword values.
* @param explicits
* a set of Doubles that are used explicitly (eg [=0], "[=1]"). May be empty or null.
* @param uniqueValue
* If non null, set to the unique value.
* @return the KeywordStatus
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
public KeywordStatus getKeywordStatus(String keyword, int offset, Set explicits,
Output uniqueValue) {
if (uniqueValue != null) {
uniqueValue.value = null;
}
if (!rules.getKeywords().contains(keyword)) {
return KeywordStatus.INVALID;
}
Collection values = getAllKeywordValues(keyword);
if (values == null) {
return KeywordStatus.UNBOUNDED;
}
int originalSize = values.size();
if (explicits == null) {
explicits = Collections.emptySet();
}
// Quick check on whether there are multiple elements
if (originalSize > explicits.size()) {
if (originalSize == 1) {
if (uniqueValue != null) {
uniqueValue.value = values.iterator().next();
}
return KeywordStatus.UNIQUE;
}
return KeywordStatus.BOUNDED;
}
// Compute if the quick test is insufficient.
HashSet subtractedSet = new HashSet(values);
for (Double explicit : explicits) {
subtractedSet.remove(explicit - offset);
}
if (subtractedSet.size() == 0) {
return KeywordStatus.SUPPRESSED;
}
if (uniqueValue != null && subtractedSet.size() == 1) {
uniqueValue.value = subtractedSet.iterator().next();
}
return originalSize == 1 ? KeywordStatus.UNIQUE : KeywordStatus.BOUNDED;
}
}