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International Component for Unicode for Java (ICU4J) is a mature, widely used Java library
providing Unicode and Globalization support
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 1996-2015, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.text;
import java.text.FieldPosition;
import java.text.ParsePosition;
import java.util.List;
import java.util.Objects;
import com.ibm.icu.impl.PatternProps;
/**
* A class representing a single rule in a RuleBasedNumberFormat. A rule
* inserts its text into the result string and then passes control to its
* substitutions, which do the same thing.
*/
final class NFRule {
//-----------------------------------------------------------------------
// constants
//-----------------------------------------------------------------------
/**
* Special base value used to identify a negative-number rule
*/
static final int NEGATIVE_NUMBER_RULE = -1;
/**
* Special base value used to identify an improper fraction (x.x) rule
*/
static final int IMPROPER_FRACTION_RULE = -2;
/**
* Special base value used to identify a proper fraction (0.x) rule
*/
static final int PROPER_FRACTION_RULE = -3;
/**
* Special base value used to identify a default rule
*/
static final int DEFAULT_RULE = -4;
/**
* Special base value used to identify an infinity rule
*/
static final int INFINITY_RULE = -5;
/**
* Special base value used to identify a not a number rule
*/
static final int NAN_RULE = -6;
static final Long ZERO = (long) 0;
//-----------------------------------------------------------------------
// data members
//-----------------------------------------------------------------------
/**
* The rule's base value
*/
private long baseValue;
/**
* The rule's radix (the radix to the power of the exponent equals
* the rule's divisor)
*/
private int radix = 10;
/**
* The rule's exponent (the radix raised to the power of the exponent
* equals the rule's divisor)
*/
private short exponent = 0;
/**
* If this is a fraction rule, this is the decimal point from DecimalFormatSymbols to match.
*/
private char decimalPoint = 0;
/**
* The rule's rule text. When formatting a number, the rule's text
* is inserted into the result string, and then the text from any
* substitutions is inserted into the result string
*/
private String ruleText = null;
/**
* The rule's plural format when defined. This is not a substitution
* because it only works on the current baseValue. It's normally not used
* due to the overhead.
*/
private PluralFormat rulePatternFormat = null;
/**
* The rule's first substitution (the one with the lower offset
* into the rule text)
*/
private NFSubstitution sub1 = null;
/**
* The rule's second substitution (the one with the higher offset
* into the rule text)
*/
private NFSubstitution sub2 = null;
/**
* The RuleBasedNumberFormat that owns this rule
*/
private final RuleBasedNumberFormat formatter;
//-----------------------------------------------------------------------
// construction
//-----------------------------------------------------------------------
/**
* Creates one or more rules based on the description passed in.
* @param description The description of the rule(s).
* @param owner The rule set containing the new rule(s).
* @param predecessor The rule that precedes the new one(s) in "owner"'s
* rule list
* @param ownersOwner The RuleBasedNumberFormat that owns the
* rule set that owns the new rule(s)
* @param returnList One or more instances of NFRule are added and returned here
*/
public static void makeRules(String description,
NFRuleSet owner,
NFRule predecessor,
RuleBasedNumberFormat ownersOwner,
List returnList) {
// we know we're making at least one rule, so go ahead and
// new it up and initialize its basevalue and divisor
// (this also strips the rule descriptor, if any, off the
// description string)
NFRule rule1 = new NFRule(ownersOwner, description);
description = rule1.ruleText;
// check the description to see whether there's text enclosed
// in brackets
int brack1 = description.indexOf('[');
int brack2 = brack1 < 0 ? -1 : description.indexOf(']');
// if the description doesn't contain a matched pair of brackets,
// or if it's of a type that doesn't recognize bracketed text,
// then leave the description alone, initialize the rule's
// rule text and substitutions, and return that rule
if (brack2 < 0 || brack1 > brack2
|| rule1.baseValue == PROPER_FRACTION_RULE
|| rule1.baseValue == NEGATIVE_NUMBER_RULE
|| rule1.baseValue == INFINITY_RULE
|| rule1.baseValue == NAN_RULE)
{
rule1.extractSubstitutions(owner, description, predecessor);
}
else {
// if the description does contain a matched pair of brackets,
// then it's really shorthand for two rules (with one exception)
NFRule rule2 = null;
StringBuilder sbuf = new StringBuilder();
// we'll actually only split the rule into two rules if its
// base value is an even multiple of its divisor (or it's one
// of the special rules)
if ((rule1.baseValue > 0
&& rule1.baseValue % (power(rule1.radix, rule1.exponent)) == 0)
|| rule1.baseValue == IMPROPER_FRACTION_RULE
|| rule1.baseValue == DEFAULT_RULE)
{
// if it passes that test, new up the second rule. If the
// rule set both rules will belong to is a fraction rule
// set, they both have the same base value; otherwise,
// increment the original rule's base value ("rule1" actually
// goes SECOND in the rule set's rule list)
rule2 = new NFRule(ownersOwner, null);
if (rule1.baseValue >= 0) {
rule2.baseValue = rule1.baseValue;
if (!owner.isFractionSet()) {
++rule1.baseValue;
}
}
else if (rule1.baseValue == IMPROPER_FRACTION_RULE) {
// if the description began with "x.x" and contains bracketed
// text, it describes both the improper fraction rule and
// the proper fraction rule
rule2.baseValue = PROPER_FRACTION_RULE;
}
else if (rule1.baseValue == DEFAULT_RULE) {
// if the description began with "x.0" and contains bracketed
// text, it describes both the default rule and the
// improper fraction rule
rule2.baseValue = rule1.baseValue;
rule1.baseValue = IMPROPER_FRACTION_RULE;
}
// both rules have the same radix and exponent (i.e., the
// same divisor)
rule2.radix = rule1.radix;
rule2.exponent = rule1.exponent;
// rule2's rule text omits the stuff in brackets: initialize
// its rule text and substitutions accordingly
sbuf.append(description.substring(0, brack1));
if (brack2 + 1 < description.length()) {
sbuf.append(description.substring(brack2 + 1));
}
rule2.extractSubstitutions(owner, sbuf.toString(), predecessor);
}
// rule1's text includes the text in the brackets but omits
// the brackets themselves: initialize _its_ rule text and
// substitutions accordingly
sbuf.setLength(0);
sbuf.append(description.substring(0, brack1));
sbuf.append(description.substring(brack1 + 1, brack2));
if (brack2 + 1 < description.length()) {
sbuf.append(description.substring(brack2 + 1));
}
rule1.extractSubstitutions(owner, sbuf.toString(), predecessor);
// if we only have one rule, return it; if we have two, return
// a two-element array containing them (notice that rule2 goes
// BEFORE rule1 in the list: in all cases, rule2 OMITS the
// material in the brackets and rule1 INCLUDES the material
// in the brackets)
if (rule2 != null) {
if (rule2.baseValue >= 0) {
returnList.add(rule2);
}
else {
owner.setNonNumericalRule(rule2);
}
}
}
if (rule1.baseValue >= 0) {
returnList.add(rule1);
}
else {
owner.setNonNumericalRule(rule1);
}
}
/**
* Nominal constructor for NFRule. Most of the work of constructing
* an NFRule is actually performed by makeRules().
*/
public NFRule(RuleBasedNumberFormat formatter, String ruleText) {
this.formatter = formatter;
this.ruleText = ruleText == null ? null : parseRuleDescriptor(ruleText);
}
/**
* This function parses the rule's rule descriptor (i.e., the base
* value and/or other tokens that precede the rule's rule text
* in the description) and sets the rule's base value, radix, and
* exponent according to the descriptor. (If the description doesn't
* include a rule descriptor, then this function sets everything to
* default values and the rule set sets the rule's real base value).
* @param description The rule's description
* @return If "description" included a rule descriptor, this is
* "description" with the descriptor and any trailing whitespace
* stripped off. Otherwise; it's "descriptor" unchanged.
*/
private String parseRuleDescriptor(String description) {
String descriptor;
// the description consists of a rule descriptor and a rule body,
// separated by a colon. The rule descriptor is optional. If
// it's omitted, just set the base value to 0.
int p = description.indexOf(":");
if (p != -1) {
// copy the descriptor out into its own string and strip it,
// along with any trailing whitespace, out of the original
// description
descriptor = description.substring(0, p);
++p;
while (p < description.length() && PatternProps.isWhiteSpace(description.charAt(p))) {
++p;
}
description = description.substring(p);
// check first to see if the rule descriptor matches the token
// for one of the special rules. If it does, set the base
// value to the correct identifier value
int descriptorLength = descriptor.length();
char firstChar = descriptor.charAt(0);
char lastChar = descriptor.charAt(descriptorLength - 1);
if (firstChar >= '0' && firstChar <= '9' && lastChar != 'x') {
// if the rule descriptor begins with a digit, it's a descriptor
// for a normal rule
long tempValue = 0;
char c = 0;
p = 0;
// begin parsing the descriptor: copy digits
// into "tempValue", skip periods, commas, and spaces,
// stop on a slash or > sign (or at the end of the string),
// and throw an exception on any other character
while (p < descriptorLength) {
c = descriptor.charAt(p);
if (c >= '0' && c <= '9') {
tempValue = tempValue * 10 + (c - '0');
}
else if (c == '/' || c == '>') {
break;
}
else if (!PatternProps.isWhiteSpace(c) && c != ',' && c != '.') {
throw new IllegalArgumentException("Illegal character " + c + " in rule descriptor");
}
++p;
}
// Set the rule's base value according to what we parsed
setBaseValue(tempValue);
// if we stopped the previous loop on a slash, we're
// now parsing the rule's radix. Again, accumulate digits
// in tempValue, skip punctuation, stop on a > mark, and
// throw an exception on anything else
if (c == '/') {
tempValue = 0;
++p;
while (p < descriptorLength) {
c = descriptor.charAt(p);
if (c >= '0' && c <= '9') {
tempValue = tempValue * 10 + (c - '0');
}
else if (c == '>') {
break;
}
else if (!PatternProps.isWhiteSpace(c) && c != ',' && c != '.') {
throw new IllegalArgumentException("Illegal character " + c + " in rule descriptor");
}
++p;
}
// tempValue now contains the rule's radix. Set it
// accordingly, and recalculate the rule's exponent
radix = (int)tempValue;
if (radix == 0) {
throw new IllegalArgumentException("Rule can't have radix of 0");
}
exponent = expectedExponent();
}
// if we stopped the previous loop on a > sign, then continue
// for as long as we still see > signs. For each one,
// decrement the exponent (unless the exponent is already 0).
// If we see another character before reaching the end of
// the descriptor, that's also a syntax error.
if (c == '>') {
while (p < descriptorLength) {
c = descriptor.charAt(p);
if (c == '>' && exponent > 0) {
--exponent;
} else {
throw new IllegalArgumentException("Illegal character in rule descriptor");
}
++p;
}
}
}
else if (descriptor.equals("-x")) {
setBaseValue(NEGATIVE_NUMBER_RULE);
}
else if (descriptorLength == 3) {
if (firstChar == '0' && lastChar == 'x') {
setBaseValue(PROPER_FRACTION_RULE);
decimalPoint = descriptor.charAt(1);
}
else if (firstChar == 'x' && lastChar == 'x') {
setBaseValue(IMPROPER_FRACTION_RULE);
decimalPoint = descriptor.charAt(1);
}
else if (firstChar == 'x' && lastChar == '0') {
setBaseValue(DEFAULT_RULE);
decimalPoint = descriptor.charAt(1);
}
else if (descriptor.equals("NaN")) {
setBaseValue(NAN_RULE);
}
else if (descriptor.equals("Inf")) {
setBaseValue(INFINITY_RULE);
}
}
}
// else use the default base value for now.
// finally, if the rule body begins with an apostrophe, strip it off
// (this is generally used to put whitespace at the beginning of
// a rule's rule text)
if (description.length() > 0 && description.charAt(0) == '\'') {
description = description.substring(1);
}
// return the description with all the stuff we've just waded through
// stripped off the front. It now contains just the rule body.
return description;
}
/**
* Searches the rule's rule text for the substitution tokens,
* creates the substitutions, and removes the substitution tokens
* from the rule's rule text.
* @param owner The rule set containing this rule
* @param predecessor The rule preceding this one in "owners" rule list
* @param ruleText The rule text
*/
private void extractSubstitutions(NFRuleSet owner,
String ruleText,
NFRule predecessor) {
this.ruleText = ruleText;
sub1 = extractSubstitution(owner, predecessor);
if (sub1 == null) {
// Small optimization. There is no need to create a redundant NullSubstitution.
sub2 = null;
}
else {
sub2 = extractSubstitution(owner, predecessor);
}
ruleText = this.ruleText;
int pluralRuleStart = ruleText.indexOf("$(");
int pluralRuleEnd = (pluralRuleStart >= 0 ? ruleText.indexOf(")$", pluralRuleStart) : -1);
if (pluralRuleEnd >= 0) {
int endType = ruleText.indexOf(',', pluralRuleStart);
if (endType < 0) {
throw new IllegalArgumentException("Rule \"" + ruleText + "\" does not have a defined type");
}
String type = this.ruleText.substring(pluralRuleStart + 2, endType);
PluralRules.PluralType pluralType;
if ("cardinal".equals(type)) {
pluralType = PluralRules.PluralType.CARDINAL;
}
else if ("ordinal".equals(type)) {
pluralType = PluralRules.PluralType.ORDINAL;
}
else {
throw new IllegalArgumentException(type + " is an unknown type");
}
rulePatternFormat = formatter.createPluralFormat(pluralType,
ruleText.substring(endType + 1, pluralRuleEnd));
}
}
/**
* Searches the rule's rule text for the first substitution token,
* creates a substitution based on it, and removes the token from
* the rule's rule text.
* @param owner The rule set containing this rule
* @param predecessor The rule preceding this one in the rule set's
* rule list
* @return The newly-created substitution. This is never null; if
* the rule text doesn't contain any substitution tokens, this will
* be a NullSubstitution.
*/
private NFSubstitution extractSubstitution(NFRuleSet owner,
NFRule predecessor) {
NFSubstitution result;
int subStart;
int subEnd;
// search the rule's rule text for the first two characters of
// a substitution token
subStart = indexOfAnyRulePrefix(ruleText);
// if we didn't find one, create a null substitution positioned
// at the end of the rule text
if (subStart == -1) {
return null;
}
// special-case the ">>>" token, since searching for the > at the
// end will actually find the > in the middle
if (ruleText.startsWith(">>>", subStart)) {
subEnd = subStart + 2;
}
else {
// otherwise the substitution token ends with the same character
// it began with
char c = ruleText.charAt(subStart);
subEnd = ruleText.indexOf(c, subStart + 1);
// special case for '<%foo<<'
if (c == '<' && subEnd != -1 && subEnd < ruleText.length() - 1 && ruleText.charAt(subEnd+1) == c) {
// ordinals use "=#,##0==%abbrev=" as their rule. Notice that the '==' in the middle
// occurs because of the juxtaposition of two different rules. The check for '<' is a hack
// to get around this. Having the duplicate at the front would cause problems with
// rules like "<<%" to format, say, percents...
++subEnd;
}
}
// if we don't find the end of the token (i.e., if we're on a single,
// unmatched token character), create a null substitution positioned
// at the end of the rule
if (subEnd == -1) {
return null;
}
// if we get here, we have a real substitution token (or at least
// some text bounded by substitution token characters). Use
// makeSubstitution() to create the right kind of substitution
result = NFSubstitution.makeSubstitution(subStart, this, predecessor, owner,
this.formatter, ruleText.substring(subStart, subEnd + 1));
// remove the substitution from the rule text
ruleText = ruleText.substring(0, subStart) + ruleText.substring(subEnd + 1);
return result;
}
/**
* Sets the rule's base value, and causes the radix and exponent
* to be recalculated. This is used during construction when we
* don't know the rule's base value until after it's been
* constructed. It should not be used at any other time.
* @param newBaseValue The new base value for the rule.
*/
final void setBaseValue(long newBaseValue) {
// set the base value
baseValue = newBaseValue;
radix = 10;
// if this isn't a special rule, recalculate the radix and exponent
// (the radix always defaults to 10; if it's supposed to be something
// else, it's cleaned up by the caller and the exponent is
// recalculated again-- the only function that does this is
// NFRule.parseRuleDescriptor() )
if (baseValue >= 1) {
exponent = expectedExponent();
// this function gets called on a fully-constructed rule whose
// description didn't specify a base value. This means it
// has substitutions, and some substitutions hold on to copies
// of the rule's divisor. Fix their copies of the divisor.
if (sub1 != null) {
sub1.setDivisor(radix, exponent);
}
if (sub2 != null) {
sub2.setDivisor(radix, exponent);
}
}
else {
// if this is a special rule, its radix and exponent are basically
// ignored. Set them to "safe" default values
exponent = 0;
}
}
/**
* This calculates the rule's exponent based on its radix and base
* value. This will be the highest power the radix can be raised to
* and still produce a result less than or equal to the base value.
*/
private short expectedExponent() {
// since the log of 0, or the log base 0 of something, causes an
// error, declare the exponent in these cases to be 0 (we also
// deal with the special-rule identifiers here)
if (radix == 0 || baseValue < 1) {
return 0;
}
// we get rounding error in some cases-- for example, log 1000 / log 10
// gives us 1.9999999996 instead of 2. The extra logic here is to take
// that into account
short tempResult = (short)(Math.log(baseValue) / Math.log(radix));
if (power(radix, (short)(tempResult + 1)) <= baseValue) {
return (short)(tempResult + 1);
} else {
return tempResult;
}
}
private static final String[] RULE_PREFIXES = new String[] {
"<<", "<%", "<#", "<0",
">>", ">%", ">#", ">0",
"=%", "=#", "=0"
};
/**
* Searches the rule's rule text for any of the specified strings.
* @return The index of the first match in the rule's rule text
* (i.e., the first substring in the rule's rule text that matches
* _any_ of the strings in "strings"). If none of the strings in
* "strings" is found in the rule's rule text, returns -1.
*/
private static int indexOfAnyRulePrefix(String ruleText) {
int result = -1;
if (ruleText.length() > 0) {
int pos;
for (String string : RULE_PREFIXES) {
pos = ruleText.indexOf(string);
if (pos != -1 && (result == -1 || pos < result)) {
result = pos;
}
}
}
return result;
}
//-----------------------------------------------------------------------
// boilerplate
//-----------------------------------------------------------------------
/**
* Tests two rules for equality.
* @param that The rule to compare this one against
* @return True if the two rules are functionally equivalent
*/
@Override
public boolean equals(Object that) {
if (that instanceof NFRule) {
NFRule that2 = (NFRule)that;
return baseValue == that2.baseValue
&& radix == that2.radix
&& exponent == that2.exponent
&& ruleText.equals(that2.ruleText)
&& Objects.equals(sub1, that2.sub1)
&& Objects.equals(sub2, that2.sub2);
}
return false;
}
@Override
public int hashCode() {
assert false : "hashCode not designed";
return 42;
}
/**
* Returns a textual representation of the rule. This won't
* necessarily be the same as the description that this rule
* was created with, but it will produce the same result.
* @return A textual description of the rule
*/
@Override
public String toString() {
StringBuilder result = new StringBuilder();
// start with the rule descriptor. Special-case the special rules
if (baseValue == NEGATIVE_NUMBER_RULE) {
result.append("-x: ");
}
else if (baseValue == IMPROPER_FRACTION_RULE) {
result.append('x').append(decimalPoint == 0 ? '.' : decimalPoint).append("x: ");
}
else if (baseValue == PROPER_FRACTION_RULE) {
result.append('0').append(decimalPoint == 0 ? '.' : decimalPoint).append("x: ");
}
else if (baseValue == DEFAULT_RULE) {
result.append('x').append(decimalPoint == 0 ? '.' : decimalPoint).append("0: ");
}
else if (baseValue == INFINITY_RULE) {
result.append("Inf: ");
}
else if (baseValue == NAN_RULE) {
result.append("NaN: ");
}
else {
// for a normal rule, write out its base value, and if the radix is
// something other than 10, write out the radix (with the preceding
// slash, of course). Then calculate the expected exponent and if
// if isn't the same as the actual exponent, write an appropriate
// number of > signs. Finally, terminate the whole thing with
// a colon.
result.append(String.valueOf(baseValue));
if (radix != 10) {
result.append('/').append(radix);
}
int numCarets = expectedExponent() - exponent;
for (int i = 0; i < numCarets; i++)
result.append('>');
result.append(": ");
}
// if the rule text begins with a space, write an apostrophe
// (whitespace after the rule descriptor is ignored; the
// apostrophe is used to make the whitespace significant)
if (ruleText.startsWith(" ") && (sub1 == null || sub1.getPos() != 0)) {
result.append('\'');
}
// now, write the rule's rule text, inserting appropriate
// substitution tokens in the appropriate places
StringBuilder ruleTextCopy = new StringBuilder(ruleText);
if (sub2 != null) {
ruleTextCopy.insert(sub2.getPos(), sub2.toString());
}
if (sub1 != null) {
ruleTextCopy.insert(sub1.getPos(), sub1.toString());
}
result.append(ruleTextCopy.toString());
// and finally, top the whole thing off with a semicolon and
// return the result
result.append(';');
return result.toString();
}
//-----------------------------------------------------------------------
// simple accessors
//-----------------------------------------------------------------------
/**
* Returns the rule's base value
* @return The rule's base value
*/
public final char getDecimalPoint() {
return decimalPoint;
}
/**
* Returns the rule's base value
* @return The rule's base value
*/
public final long getBaseValue() {
return baseValue;
}
/**
* Returns the rule's divisor (the value that controls the behavior
* of its substitutions)
* @return The rule's divisor
*/
public long getDivisor() {
return power(radix, exponent);
}
//-----------------------------------------------------------------------
// formatting
//-----------------------------------------------------------------------
/**
* Formats the number, and inserts the resulting text into
* toInsertInto.
* @param number The number being formatted
* @param toInsertInto The string where the resultant text should
* be inserted
* @param pos The position in toInsertInto where the resultant text
* should be inserted
*/
public void doFormat(long number, StringBuilder toInsertInto, int pos, int recursionCount) {
// first, insert the rule's rule text into toInsertInto at the
// specified position, then insert the results of the substitutions
// into the right places in toInsertInto (notice we do the
// substitutions in reverse order so that the offsets don't get
// messed up)
int pluralRuleStart = ruleText.length();
int lengthOffset = 0;
if (rulePatternFormat == null) {
toInsertInto.insert(pos, ruleText);
}
else {
pluralRuleStart = ruleText.indexOf("$(");
int pluralRuleEnd = ruleText.indexOf(")$", pluralRuleStart);
int initialLength = toInsertInto.length();
if (pluralRuleEnd < ruleText.length() - 1) {
toInsertInto.insert(pos, ruleText.substring(pluralRuleEnd + 2));
}
toInsertInto.insert(pos, rulePatternFormat.format(number / power(radix, exponent)));
if (pluralRuleStart > 0) {
toInsertInto.insert(pos, ruleText.substring(0, pluralRuleStart));
}
lengthOffset = ruleText.length() - (toInsertInto.length() - initialLength);
}
if (sub2 != null) {
sub2.doSubstitution(number, toInsertInto, pos - (sub2.getPos() > pluralRuleStart ? lengthOffset : 0), recursionCount);
}
if (sub1 != null) {
sub1.doSubstitution(number, toInsertInto, pos - (sub1.getPos() > pluralRuleStart ? lengthOffset : 0), recursionCount);
}
}
/**
* Formats the number, and inserts the resulting text into
* toInsertInto.
* @param number The number being formatted
* @param toInsertInto The string where the resultant text should
* be inserted
* @param pos The position in toInsertInto where the resultant text
* should be inserted
*/
public void doFormat(double number, StringBuilder toInsertInto, int pos, int recursionCount) {
// first, insert the rule's rule text into toInsertInto at the
// specified position, then insert the results of the substitutions
// into the right places in toInsertInto
// [again, we have two copies of this routine that do the same thing
// so that we don't sacrifice precision in a long by casting it
// to a double]
int pluralRuleStart = ruleText.length();
int lengthOffset = 0;
if (rulePatternFormat == null) {
toInsertInto.insert(pos, ruleText);
}
else {
pluralRuleStart = ruleText.indexOf("$(");
int pluralRuleEnd = ruleText.indexOf(")$", pluralRuleStart);
int initialLength = toInsertInto.length();
if (pluralRuleEnd < ruleText.length() - 1) {
toInsertInto.insert(pos, ruleText.substring(pluralRuleEnd + 2));
}
double pluralVal = number;
if (0 <= pluralVal && pluralVal < 1) {
// We're in a fractional rule, and we have to match the NumeratorSubstitution behavior.
// 2.3 can become 0.2999999999999998 for the fraction due to rounding errors.
pluralVal = Math.round(pluralVal * power(radix, exponent));
}
else {
pluralVal = pluralVal / power(radix, exponent);
}
toInsertInto.insert(pos, rulePatternFormat.format((long)(pluralVal)));
if (pluralRuleStart > 0) {
toInsertInto.insert(pos, ruleText.substring(0, pluralRuleStart));
}
lengthOffset = ruleText.length() - (toInsertInto.length() - initialLength);
}
if (sub2 != null) {
sub2.doSubstitution(number, toInsertInto, pos - (sub2.getPos() > pluralRuleStart ? lengthOffset : 0), recursionCount);
}
if (sub1 != null) {
sub1.doSubstitution(number, toInsertInto, pos - (sub1.getPos() > pluralRuleStart ? lengthOffset : 0), recursionCount);
}
}
/**
* This is an equivalent to Math.pow that accurately works on 64-bit numbers
* @param base The base
* @param exponent The exponent
* @return radix ** exponent
* @see Math#pow(double, double)
*/
static long power(long base, short exponent) {
if (exponent < 0) {
throw new IllegalArgumentException("Exponent can not be negative");
}
if (base < 0) {
throw new IllegalArgumentException("Base can not be negative");
}
long result = 1;
while (exponent > 0) {
if ((exponent & 1) == 1) {
result *= base;
}
base *= base;
exponent >>= 1;
}
return result;
}
/**
* Used by the owning rule set to determine whether to invoke the
* rollback rule (i.e., whether this rule or the one that precedes
* it in the rule set's list should be used to format the number)
* @param number The number being formatted
* @return True if the rule set should use the rule that precedes
* this one in its list; false if it should use this rule
*/
public boolean shouldRollBack(long number) {
// we roll back if the rule contains a modulus substitution,
// the number being formatted is an even multiple of the rule's
// divisor, and the rule's base value is NOT an even multiple
// of its divisor
// In other words, if the original description had
// 100: << hundred[ >>];
// that expands into
// 100: << hundred;
// 101: << hundred >>;
// internally. But when we're formatting 200, if we use the rule
// at 101, which would normally apply, we get "two hundred zero".
// To prevent this, we roll back and use the rule at 100 instead.
// This is the logic that makes this happen: the rule at 101 has
// a modulus substitution, its base value isn't an even multiple
// of 100, and the value we're trying to format _is_ an even
// multiple of 100. This is called the "rollback rule."
if (!((sub1 != null && sub1.isModulusSubstitution()) || (sub2 != null && sub2.isModulusSubstitution()))) {
return false;
}
long divisor = power(radix, exponent);
return (number % divisor) == 0 && (baseValue % divisor) != 0;
}
//-----------------------------------------------------------------------
// parsing
//-----------------------------------------------------------------------
/**
* Attempts to parse the string with this rule.
* @param text The string being parsed
* @param parsePosition On entry, the value is ignored and assumed to
* be 0. On exit, this has been updated with the position of the first
* character not consumed by matching the text against this rule
* (if this rule doesn't match the text at all, the parse position
* if left unchanged (presumably at 0) and the function returns
* new Long(0)).
* @param isFractionRule True if this rule is contained within a
* fraction rule set. This is only used if the rule has no
* substitutions.
* @return If this rule matched the text, this is the rule's base value
* combined appropriately with the results of parsing the substitutions.
* If nothing matched, this is new Long(0) and the parse position is
* left unchanged. The result will be an instance of Long if the
* result is an integer and Double otherwise. The result is never null.
*/
public Number doParse(String text, ParsePosition parsePosition, boolean isFractionRule,
double upperBound, int nonNumericalExecutedRuleMask) {
// internally we operate on a copy of the string being parsed
// (because we're going to change it) and use our own ParsePosition
ParsePosition pp = new ParsePosition(0);
// check to see whether the text before the first substitution
// matches the text at the beginning of the string being
// parsed. If it does, strip that off the front of workText;
// otherwise, dump out with a mismatch
int sub1Pos = sub1 != null ? sub1.getPos() : ruleText.length();
int sub2Pos = sub2 != null ? sub2.getPos() : ruleText.length();
String workText = stripPrefix(text, ruleText.substring(0, sub1Pos), pp);
int prefixLength = text.length() - workText.length();
if (pp.getIndex() == 0 && sub1Pos != 0) {
// commented out because ParsePosition doesn't have error index in 1.1.x
// parsePosition.setErrorIndex(pp.getErrorIndex());
return ZERO;
}
if (baseValue == INFINITY_RULE) {
// If you match this, don't try to perform any calculations on it.
parsePosition.setIndex(pp.getIndex());
return Double.POSITIVE_INFINITY;
}
if (baseValue == NAN_RULE) {
// If you match this, don't try to perform any calculations on it.
parsePosition.setIndex(pp.getIndex());
return Double.NaN;
}
// this is the fun part. The basic guts of the rule-matching
// logic is matchToDelimiter(), which is called twice. The first
// time it searches the input string for the rule text BETWEEN
// the substitutions and tries to match the intervening text
// in the input string with the first substitution. If that
// succeeds, it then calls it again, this time to look for the
// rule text after the second substitution and to match the
// intervening input text against the second substitution.
//
// For example, say we have a rule that looks like this:
// first << middle >> last;
// and input text that looks like this:
// first one middle two last
// First we use stripPrefix() to match "first " in both places and
// strip it off the front, leaving
// one middle two last
// Then we use matchToDelimiter() to match " middle " and try to
// match "one" against a substitution. If it's successful, we now
// have
// two last
// We use matchToDelimiter() a second time to match " last" and
// try to match "two" against a substitution. If "two" matches
// the substitution, we have a successful parse.
//
// Since it's possible in many cases to find multiple instances
// of each of these pieces of rule text in the input string,
// we need to try all the possible combinations of these
// locations. This prevents us from prematurely declaring a mismatch,
// and makes sure we match as much input text as we can.
int highWaterMark = 0;
double result = 0;
int start = 0;
double tempBaseValue = Math.max(0, baseValue);
do {
// our partial parse result starts out as this rule's base
// value. If it finds a successful match, matchToDelimiter()
// will compose this in some way with what it gets back from
// the substitution, giving us a new partial parse result
pp.setIndex(0);
double partialResult = matchToDelimiter(workText, start, tempBaseValue,
ruleText.substring(sub1Pos, sub2Pos), rulePatternFormat,
pp, sub1, upperBound, nonNumericalExecutedRuleMask).doubleValue();
// if we got a successful match (or were trying to match a
// null substitution), pp is now pointing at the first unmatched
// character. Take note of that, and try matchToDelimiter()
// on the input text again
if (pp.getIndex() != 0 || sub1 == null) {
start = pp.getIndex();
String workText2 = workText.substring(pp.getIndex());
ParsePosition pp2 = new ParsePosition(0);
// the second matchToDelimiter() will compose our previous
// partial result with whatever it gets back from its
// substitution if there's a successful match, giving us
// a real result
partialResult = matchToDelimiter(workText2, 0, partialResult,
ruleText.substring(sub2Pos), rulePatternFormat, pp2, sub2,
upperBound, nonNumericalExecutedRuleMask).doubleValue();
// if we got a successful match on this second
// matchToDelimiter() call, update the high-water mark
// and result (if necessary)
if (pp2.getIndex() != 0 || sub2 == null) {
if (prefixLength + pp.getIndex() + pp2.getIndex() > highWaterMark) {
highWaterMark = prefixLength + pp.getIndex() + pp2.getIndex();
result = partialResult;
}
}
// commented out because ParsePosition doesn't have error index in 1.1.x
// else {
// int temp = pp2.getErrorIndex() + sub1.getPos() + pp.getIndex();
// if (temp> parsePosition.getErrorIndex()) {
// parsePosition.setErrorIndex(temp);
// }
// }
}
// commented out because ParsePosition doesn't have error index in 1.1.x
// else {
// int temp = sub1.getPos() + pp.getErrorIndex();
// if (temp > parsePosition.getErrorIndex()) {
// parsePosition.setErrorIndex(temp);
// }
// }
// keep trying to match things until the outer matchToDelimiter()
// call fails to make a match (each time, it picks up where it
// left off the previous time)
}
while (sub1Pos != sub2Pos && pp.getIndex() > 0 && pp.getIndex()
< workText.length() && pp.getIndex() != start);
// update the caller's ParsePosition with our high-water mark
// (i.e., it now points at the first character this function
// didn't match-- the ParsePosition is therefore unchanged if
// we didn't match anything)
parsePosition.setIndex(highWaterMark);
// commented out because ParsePosition doesn't have error index in 1.1.x
// if (highWaterMark > 0) {
// parsePosition.setErrorIndex(0);
// }
// this is a hack for one unusual condition: Normally, whether this
// rule belong to a fraction rule set or not is handled by its
// substitutions. But if that rule HAS NO substitutions, then
// we have to account for it here. By definition, if the matching
// rule in a fraction rule set has no substitutions, its numerator
// is 1, and so the result is the reciprocal of its base value.
if (isFractionRule && highWaterMark > 0 && sub1 == null) {
result = 1 / result;
}
// return the result as a Long if possible, or as a Double
if (result == (long)result) {
return Long.valueOf((long)result);
} else {
return new Double(result);
}
}
/**
* This function is used by parse() to match the text being parsed
* against a possible prefix string. This function
* matches characters from the beginning of the string being parsed
* to characters from the prospective prefix. If they match, pp is
* updated to the first character not matched, and the result is
* the unparsed part of the string. If they don't match, the whole
* string is returned, and pp is left unchanged.
* @param text The string being parsed
* @param prefix The text to match against
* @param pp On entry, ignored and assumed to be 0. On exit, points
* to the first unmatched character (assuming the whole prefix matched),
* or is unchanged (if the whole prefix didn't match).
* @return If things match, this is the unparsed part of "text";
* if they didn't match, this is "text".
*/
private String stripPrefix(String text, String prefix, ParsePosition pp) {
// if the prefix text is empty, dump out without doing anything
if (prefix.length() == 0) {
return text;
} else {
// otherwise, use prefixLength() to match the beginning of
// "text" against "prefix". This function returns the
// number of characters from "text" that matched (or 0 if
// we didn't match the whole prefix)
int pfl = prefixLength(text, prefix);
if (pfl != 0) {
// if we got a successful match, update the parse position
// and strip the prefix off of "text"
pp.setIndex(pp.getIndex() + pfl);
return text.substring(pfl);
// if we didn't get a successful match, leave everything alone
} else {
return text;
}
}
}
/**
* Used by parse() to match a substitution and any following text.
* "text" is searched for instances of "delimiter". For each instance
* of delimiter, the intervening text is tested to see whether it
* matches the substitution. The longest match wins.
* @param text The string being parsed
* @param startPos The position in "text" where we should start looking
* for "delimiter".
* @param baseVal A partial parse result (often the rule's base value),
* which is combined with the result from matching the substitution
* @param delimiter The string to search "text" for.
* @param pp Ignored and presumed to be 0 on entry. If there's a match,
* on exit this will point to the first unmatched character.
* @param sub If we find "delimiter" in "text", this substitution is used
* to match the text between the beginning of the string and the
* position of "delimiter." (If "delimiter" is the empty string, then
* this function just matches against this substitution and updates
* everything accordingly.)
* @param upperBound When matching the substitution, it will only
* consider rules with base values lower than this value.
* @return If there's a match, this is the result of composing
* baseValue with the result of matching the substitution. Otherwise,
* this is new Long(0). It's never null. If the result is an integer,
* this will be an instance of Long; otherwise, it's an instance of
* Double.
*/
private Number matchToDelimiter(String text, int startPos, double baseVal,
String delimiter, PluralFormat pluralFormatDelimiter, ParsePosition pp, NFSubstitution sub,
double upperBound, int nonNumericalExecutedRuleMask) {
// if "delimiter" contains real (i.e., non-ignorable) text, search
// it for "delimiter" beginning at "start". If that succeeds, then
// use "sub"'s doParse() method to match the text before the
// instance of "delimiter" we just found.
if (!allIgnorable(delimiter)) {
ParsePosition tempPP = new ParsePosition(0);
Number tempResult;
// use findText() to search for "delimiter". It returns a two-
// element array: element 0 is the position of the match, and
// element 1 is the number of characters that matched
// "delimiter".
int[] temp = findText(text, delimiter, pluralFormatDelimiter, startPos);
int dPos = temp[0];
int dLen = temp[1];
// if findText() succeeded, isolate the text preceding the
// match, and use "sub" to match that text
while (dPos >= 0) {
String subText = text.substring(0, dPos);
if (subText.length() > 0) {
tempResult = sub.doParse(subText, tempPP, baseVal, upperBound,
formatter.lenientParseEnabled(), nonNumericalExecutedRuleMask);
// if the substitution could match all the text up to
// where we found "delimiter", then this function has
// a successful match. Bump the caller's parse position
// to point to the first character after the text
// that matches "delimiter", and return the result
// we got from parsing the substitution.
if (tempPP.getIndex() == dPos) {
pp.setIndex(dPos + dLen);
return tempResult;
}
// commented out because ParsePosition doesn't have error index in 1.1.x
// else {
// if (tempPP.getErrorIndex() > 0) {
// pp.setErrorIndex(tempPP.getErrorIndex());
// } else {
// pp.setErrorIndex(tempPP.getIndex());
// }
// }
}
// if we didn't match the substitution, search for another
// copy of "delimiter" in "text" and repeat the loop if
// we find it
tempPP.setIndex(0);
temp = findText(text, delimiter, pluralFormatDelimiter, dPos + dLen);
dPos = temp[0];
dLen = temp[1];
}
// if we make it here, this was an unsuccessful match, and we
// leave pp unchanged and return 0
pp.setIndex(0);
return ZERO;
// if "delimiter" is empty, or consists only of ignorable characters
// (i.e., is semantically empty), thwe we obviously can't search
// for "delimiter". Instead, just use "sub" to parse as much of
// "text" as possible.
}
else if (sub == null) {
return baseVal;
}
else {
ParsePosition tempPP = new ParsePosition(0);
Number result = ZERO;
// try to match the whole string against the substitution
Number tempResult = sub.doParse(text, tempPP, baseVal, upperBound,
formatter.lenientParseEnabled(), nonNumericalExecutedRuleMask);
if (tempPP.getIndex() != 0) {
// if there's a successful match (or it's a null
// substitution), update pp to point to the first
// character we didn't match, and pass the result from
// sub.doParse() on through to the caller
pp.setIndex(tempPP.getIndex());
if (tempResult != null) {
result = tempResult;
}
}
// commented out because ParsePosition doesn't have error index in 1.1.x
// else {
// pp.setErrorIndex(tempPP.getErrorIndex());
// }
// and if we get to here, then nothing matched, so we return
// 0 and leave pp alone
return result;
}
}
/**
* Used by stripPrefix() to match characters. If lenient parse mode
* is off, this just calls startsWith(). If lenient parse mode is on,
* this function uses CollationElementIterators to match characters in
* the strings (only primary-order differences are significant in
* determining whether there's a match).
* @param str The string being tested
* @param prefix The text we're hoping to see at the beginning
* of "str"
* @return If "prefix" is found at the beginning of "str", this
* is the number of characters in "str" that were matched (this
* isn't necessarily the same as the length of "prefix" when matching
* text with a collator). If there's no match, this is 0.
*/
private int prefixLength(String str, String prefix) {
// if we're looking for an empty prefix, it obviously matches
// zero characters. Just go ahead and return 0.
if (prefix.length() == 0) {
return 0;
}
RbnfLenientScanner scanner = formatter.getLenientScanner();
if (scanner != null) {
// Check if non-lenient rule finds the text before call lenient parsing
if (str.startsWith(prefix)) {
return prefix.length();
}
return scanner.prefixLength(str, prefix);
}
// If lenient parsing is turned off, forget all that crap above.
// Just use String.startsWith() and be done with it.
if (str.startsWith(prefix)) {
return prefix.length();
}
return 0;
}
/**
* Searches a string for another string. If lenient parsing is off,
* this just calls indexOf(). If lenient parsing is on, this function
* uses CollationElementIterator to match characters, and only
* primary-order differences are significant in determining whether
* there's a match.
* @param str The string to search
* @param key The string to search "str" for
* @param startingAt The index into "str" where the search is to
* begin
* @return A two-element array of ints. Element 0 is the position
* of the match, or -1 if there was no match. Element 1 is the
* number of characters in "str" that matched (which isn't necessarily
* the same as the length of "key")
*/
private int[] findText(String str, String key, PluralFormat pluralFormatKey, int startingAt) {
RbnfLenientScanner scanner = formatter.getLenientScanner();
if (pluralFormatKey != null) {
FieldPosition position = new FieldPosition(NumberFormat.INTEGER_FIELD);
position.setBeginIndex(startingAt);
pluralFormatKey.parseType(str, scanner, position);
int start = position.getBeginIndex();
if (start >= 0) {
int pluralRuleStart = ruleText.indexOf("$(");
int pluralRuleSuffix = ruleText.indexOf(")$", pluralRuleStart) + 2;
int matchLen = position.getEndIndex() - start;
String prefix = ruleText.substring(0, pluralRuleStart);
String suffix = ruleText.substring(pluralRuleSuffix);
if (str.regionMatches(start - prefix.length(), prefix, 0, prefix.length())
&& str.regionMatches(start + matchLen, suffix, 0, suffix.length()))
{
return new int[]{start - prefix.length(), matchLen + prefix.length() + suffix.length()};
}
}
return new int[]{-1, 0};
}
if (scanner != null) {
// Check if non-lenient rule finds the text before call lenient parsing
int pos[] = new int[] { str.indexOf(key, startingAt), key.length() };
if (pos[0] >= 0) {
return pos;
} else {
// if lenient parsing is turned ON, we've got some work ahead of us
return scanner.findText(str, key, startingAt);
}
}
// if lenient parsing is turned off, this is easy. Just call
// String.indexOf() and we're done
return new int[]{str.indexOf(key, startingAt), key.length()};
}
/**
* Checks to see whether a string consists entirely of ignorable
* characters.
* @param str The string to test.
* @return true if the string is empty of consists entirely of
* characters that the number formatter's collator says are
* ignorable at the primary-order level. false otherwise.
*/
private boolean allIgnorable(String str) {
// if the string is empty, we can just return true
if (str == null || str.length() == 0) {
return true;
}
RbnfLenientScanner scanner = formatter.getLenientScanner();
return scanner != null && scanner.allIgnorable(str);
}
public void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols) {
if (sub1 != null) {
sub1.setDecimalFormatSymbols(newSymbols);
}
if (sub2 != null) {
sub2.setDecimalFormatSymbols(newSymbols);
}
}
}