blob: 6f2299051a93d2b400b83b0a04b294659a0ecc53 [file] [log] [blame]
 /* ****************************************************************************** * Copyright (C) 1997-2001, International Business Machines * Corporation and others. All Rights Reserved. ****************************************************************************** * file name: nfrs.cpp * encoding: US-ASCII * tab size: 8 (not used) * indentation:4 * * Modification history * Date Name Comments * 10/11/2001 Doug Ported from ICU4J */ #include "nfrs.h" #include "nfrule.h" #include "nfrlist.h" #include "cmemory.h" U_NAMESPACE_BEGIN #if 0 // euclid's algorithm works with doubles // note, doubles only get us up to one quadrillion or so, which // isn't as much range as we get with longs. We probably still // want either 64-bit math, or BigInteger. static llong util_lcm(llong x, llong y) { x.abs(); y.abs(); if (x == 0 || y == 0) { return 0; } else { do { if (x < y) { llong t = x; x = y; y = t; } x -= y * (x/y); } while (x != 0); return y; } } #else /** * Calculates the least common multiple of x and y. */ static llong util_lcm(llong x, llong y) { // binary gcd algorithm from Knuth, "The Art of Computer Programming," // vol. 2, 1st ed., pp. 298-299 llong x1 = x; llong y1 = y; int p2 = 0; while ((x1 & 1) == 0 && (y1 & 1) == 0) { ++p2; x1 >>= 1; y1 >>= 1; } llong t; if ((x1 & 1) == 1) { t = -y1; } else { t = x1; } while (t != 0) { while ((t & 1) == 0) { t >>= 1; } if (t > 0) { x1 = t; } else { y1 = -t; } t = x1 - y1; } llong gcd = x1 << p2; // x * y == gcd(x, y) * lcm(x, y) return x / gcd * y; } #endif static const UChar gPercent = 0x0025; static const UChar gColon = 0x003a; static const UChar gSemicolon = 0x003b; static const UChar gLineFeed = 0x0010; static const UChar gFourSpaces[] = { 0x20, 0x20, 0x20, 0x20, 0 }; /* " " */ static const UChar gPercentPercent[] = { 0x25, 0x25, 0 }; /* "%%" */ NFRuleSet::NFRuleSet(UnicodeString* descriptions, int32_t index, UErrorCode& status) : name() , rules(0) , negativeNumberRule(NULL) , fIsFractionRuleSet(FALSE) , fIsPublic(FALSE) { for (int i = 0; i < 3; ++i) { fractionRules[i] = NULL; } if (U_FAILURE(status)) { return; } UnicodeString& description = descriptions[index]; // !!! make sure index is valid // if the description begins with a rule set name (the rule set // name can be omitted in formatter descriptions that consist // of only one rule set), copy it out into our "name" member // and delete it from the description if (description.charAt(0) == gPercent) { UTextOffset pos = description.indexOf(gColon); if (pos == -1) { // throw new IllegalArgumentException("Rule set name doesn't end in colon"); status = U_PARSE_ERROR; } else { name.setTo(description, 0, pos); while (pos < description.length() && u_isWhitespace(description.charAt(++pos))) { } description.remove(0, pos); } } else { name.setTo("%default"); } if (description.length() == 0) { // throw new IllegalArgumentException("Empty rule set description"); status = U_PARSE_ERROR; } fIsPublic = name.indexOf(gPercentPercent) != 0; // all of the other members of NFRuleSet are initialized // by parseRules() } void NFRuleSet::parseRules(UnicodeString& description, const RuleBasedNumberFormat* owner, UErrorCode& status) { // start by creating a Vector whose elements are Strings containing // the descriptions of the rules (one rule per element). The rules // are separated by semicolons (there's no escape facility: ALL // semicolons are rule delimiters) if (U_FAILURE(status)) { return; } // dlf - the original code kept a separate description array for no reason, // so I got rid of it. The loop was too complex so I simplified it. UnicodeString currentDescription; UTextOffset oldP = 0; while (oldP < description.length()) { UTextOffset p = description.indexOf(gSemicolon, oldP); if (p == -1) { p = description.length(); } currentDescription.setTo(description, oldP, p - oldP); NFRule::makeRules(currentDescription, this, rules.last(), owner, rules, status); oldP = p + 1; } // for rules that didn't specify a base value, their base values // were initialized to 0. Make another pass through the list and // set all those rules' base values. We also remove any special // rules from the list and put them into their own member variables llong defaultBaseValue = (int32_t)0; // (this isn't a for loop because we might be deleting items from // the vector-- we want to make sure we only increment i when // we _didn't_ delete aything from the vector) uint32_t i = 0; while (i < rules.size()) { NFRule* rule = rules[i]; switch (rule->getType()) { // if the rule's base value is 0, fill in a default // base value (this will be 1 plus the preceding // rule's base value for regular rule sets, and the // same as the preceding rule's base value in fraction // rule sets) case NFRule::kNoBase: rule->setBaseValue(defaultBaseValue); if (!isFractionRuleSet()) { ++defaultBaseValue; } ++i; break; // if it's the negative-number rule, copy it into its own // data member and delete it from the list case NFRule::kNegativeNumberRule: negativeNumberRule = rules.remove(i); break; // if it's the improper fraction rule, copy it into the // correct element of fractionRules case NFRule::kImproperFractionRule: fractionRules[0] = rules.remove(i); break; // if it's the proper fraction rule, copy it into the // correct element of fractionRules case NFRule::kProperFractionRule: fractionRules[1] = rules.remove(i); break; // if it's the master rule, copy it into the // correct element of fractionRules case NFRule::kMasterRule: fractionRules[2] = rules.remove(i); break; // if it's a regular rule that already knows its base value, // check to make sure the rules are in order, and update // the default base value for the next rule default: if (rule->getBaseValue() < defaultBaseValue) { // throw new IllegalArgumentException("Rules are not in order"); status = U_PARSE_ERROR; return; } defaultBaseValue = rule->getBaseValue(); if (!isFractionRuleSet()) { ++defaultBaseValue; } ++i; break; } } } NFRuleSet::~NFRuleSet() { delete negativeNumberRule; delete fractionRules[0]; delete fractionRules[1]; delete fractionRules[2]; } UBool util_equalRules(const NFRule* rule1, const NFRule* rule2) { if (rule1) { if (rule2) { return *rule1 == *rule2; } } else if (!rule2) { return TRUE; } return FALSE; } UBool NFRuleSet::operator==(const NFRuleSet& rhs) const { if (rules.size() == rhs.rules.size() && fIsFractionRuleSet == rhs.fIsFractionRuleSet && name == rhs.name && util_equalRules(negativeNumberRule, rhs.negativeNumberRule) && util_equalRules(fractionRules[0], rhs.fractionRules[0]) && util_equalRules(fractionRules[1], rhs.fractionRules[1]) && util_equalRules(fractionRules[2], rhs.fractionRules[2])) { for (uint32_t i = 0; i < rules.size(); ++i) { if (*rules[i] != *rhs.rules[i]) { return FALSE; } } return TRUE; } return FALSE; } void NFRuleSet::format(llong number, UnicodeString& toAppendTo, int32_t pos) const { NFRule *rule = findNormalRule(number); rule->doFormat(number, toAppendTo, pos); } void NFRuleSet::format(double number, UnicodeString& toAppendTo, int32_t pos) const { NFRule *rule = findDoubleRule(number); rule->doFormat(number, toAppendTo, pos); } NFRule* NFRuleSet::findDoubleRule(double number) const { // if this is a fraction rule set, use findFractionRuleSetRule() if (isFractionRuleSet()) { return findFractionRuleSetRule(number); } // if the number is negative, return the negative number rule // (if there isn't a negative-number rule, we pretend it's a // positive number) if (number < 0) { if (negativeNumberRule) { return negativeNumberRule; } else { number = -number; } } // if the number isn't an integer, we use one of the fraction rules... if (number != uprv_floor(number)) { // if the number is between 0 and 1, return the proper // fraction rule if (number < 1 && fractionRules[1]) { return fractionRules[1]; } // otherwise, return the improper fraction rule else if (fractionRules[0]) { return fractionRules[0]; } } // if there's a master rule, use it to format the number if (fractionRules[2]) { return fractionRules[2]; } // and if we haven't yet returned a rule, use findNormalRule() // to find the applicable rule llong r = number + 0.5; return findNormalRule(r); } NFRule * NFRuleSet::findNormalRule(llong number) const { // if this is a fraction rule set, use findFractionRuleSetRule() // to find the rule (we should only go into this clause if the // value is 0) if (fIsFractionRuleSet) { return findFractionRuleSetRule(number.asDouble()); } // if the number is negative, return the negative-number rule // (if there isn't one, pretend the number is positive) if (number < 0) { if (negativeNumberRule) { return negativeNumberRule; } else { number = -number; } } // we have to repeat the preceding two checks, even though we // do them in findRule(), because the version of format() that // takes a long bypasses findRule() and goes straight to this // function. This function does skip the fraction rules since // we know the value is an integer (it also skips the master // rule, since it's considered a fraction rule. Skipping the // master rule in this function is also how we avoid infinite // recursion) // binary-search the rule list for the applicable rule // (a rule is used for all values from its base value to // the next rule's base value) int32_t lo = 0; int32_t hi = rules.size(); while (lo < hi) { int32_t mid = (lo + hi) / 2; if (rules[mid]->getBaseValue() == number) { return rules[mid]; } else if (rules[mid]->getBaseValue() > number) { hi = mid; } else { lo = mid + 1; } } NFRule *result = rules[hi - 1]; // use shouldRollBack() to see whether we need to invoke the // rollback rule (see shouldRollBack()'s documentation for // an explanation of the rollback rule). If we do, roll back // one rule and return that one instead of the one we'd normally // return if (result->shouldRollBack(number.asDouble())) { result = rules[hi - 2]; } return result; } /** * If this rule is a fraction rule set, this function is used by * findRule() to select the most appropriate rule for formatting * the number. Basically, the base value of each rule in the rule * set is treated as the denominator of a fraction. Whichever * denominator can produce the fraction closest in value to the * number passed in is the result. If there's a tie, the earlier * one in the list wins. (If there are two rules in a row with the * same base value, the first one is used when the numerator of the * fraction would be 1, and the second rule is used the rest of the * time. * @param number The number being formatted (which will always be * a number between 0 and 1) * @return The rule to use to format this number */ NFRule* NFRuleSet::findFractionRuleSetRule(double number) const { // the obvious way to do this (multiply the value being formatted // by each rule's base value until you get an integral result) // doesn't work because of rounding error. This method is more // accurate // find the least common multiple of the rules' base values // and multiply this by the number being formatted. This is // all the precision we need, and we can do all of the rest // of the math using integer arithmetic llong leastCommonMultiple = rules[0]->getBaseValue(); llong numerator; { for (uint32_t i = 1; i < rules.size(); ++i) { leastCommonMultiple = util_lcm(leastCommonMultiple, rules[i]->getBaseValue()); } numerator = number * leastCommonMultiple.asDouble() + 0.5; } // for each rule, do the following... llong tempDifference; llong difference(uprv_maxMantissa()); int32_t winner = 0; for (uint32_t i = 0; i < rules.size(); ++i) { // "numerator" is the numerator of the fraction if the // denominator is the LCD. The numerator if the rule's // base value is the denominator is "numerator" times the // base value divided bythe LCD. Here we check to see if // that's an integer, and if not, how close it is to being // an integer. tempDifference = numerator * rules[i]->getBaseValue() % leastCommonMultiple; // normalize the result of the above calculation: we want // the numerator's distance from the CLOSEST multiple // of the LCD if (leastCommonMultiple - tempDifference < tempDifference) { tempDifference = leastCommonMultiple - tempDifference; } // if this is as close as we've come, keep track of how close // that is, and the line number of the rule that did it. If // we've scored a direct hit, we don't have to look at any more // rules if (tempDifference < difference) { difference = tempDifference; winner = i; if (difference == 0) { break; } } } // if we have two successive rules that both have the winning base // value, then the first one (the one we found above) is used if // the numerator of the fraction is 1 and the second one is used if // the numerator of the fraction is anything else (this lets us // do things like "one third"/"two thirds" without haveing to define // a whole bunch of extra rule sets) if ((unsigned)(winner + 1) < rules.size() && rules[winner + 1]->getBaseValue() == rules[winner]->getBaseValue()) { double n = rules[winner]->getBaseValue().asDouble() * number; if (n < 0.5 || n >= 2) { ++winner; } } // finally, return the winning rule return rules[winner]; } /** * Parses a string. Matches the string to be parsed against each * of its rules (with a base value less than upperBound) and returns * the value produced by the rule that matched the most charcters * in the source string. * @param text The string to parse * @param parsePosition The initial position is ignored and assumed * to be 0. On exit, this object has been updated to point to the * first character position this rule set didn't consume. * @param upperBound Limits the rules that can be allowed to match. * Only rules whose base values are strictly less than upperBound * are considered. * @return The numerical result of parsing this string. This will * be the matching rule's base value, composed appropriately with * the results of matching any of its substitutions. The object * will be an instance of Long if it's an integral value; otherwise, * it will be an instance of Double. This function always returns * a valid object: If nothing matched the input string at all, * this function returns new Long(0), and the parse position is * left unchanged. */ #ifdef RBNF_DEBUG #include static void dumpUS(FILE* f, const UnicodeString& us) { int len = us.length(); char* buf = new char[len+1]; us.extract(0, len, buf); buf[len] = 0; fprintf(f, "%s", buf); delete[] buf; } #endif UBool NFRuleSet::parse(const UnicodeString& text, ParsePosition& pos, double upperBound, Formattable& result) const { // try matching each rule in the rule set against the text being // parsed. Whichever one matches the most characters is the one // that determines the value we return. result.setLong(0); // dump out if there's no text to parse if (text.length() == 0) { return 0; } ParsePosition highWaterMark; ParsePosition workingPos = pos; #ifdef RBNF_DEBUG fprintf(stderr, " %x '", this); dumpUS(stderr, name); fprintf(stderr, "' text '"); dumpUS(stderr, text); fprintf(stderr, "'\n"); fprintf(stderr, " parse negative: %d\n", this, negativeNumberRule != 0); #endif // start by trying the negative number rule (if there is one) if (negativeNumberRule) { Formattable tempResult; #ifdef RBNF_DEBUG fprintf(stderr, " %x ub: %g\n", negativeNumberRule, upperBound); #endif UBool success = negativeNumberRule->doParse(text, workingPos, 0, upperBound, tempResult); #ifdef RBNF_DEBUG fprintf(stderr, " success: %d wpi: %d\n", success, workingPos.getIndex()); #endif if (success && workingPos.getIndex() > highWaterMark.getIndex()) { result = tempResult; highWaterMark = workingPos; } workingPos = pos; } #ifdef RBNF_DEBUG fprintf(stderr, " continue fractional with text '"); dumpUS(stderr, text); fprintf(stderr, "' hwm: %d\n", highWaterMark.getIndex()); #endif // then try each of the fraction rules { for (int i = 0; i < 3; i++) { if (fractionRules[i]) { Formattable tempResult; UBool success = fractionRules[i]->doParse(text, workingPos, 0, upperBound, tempResult); if (success && (workingPos.getIndex() > highWaterMark.getIndex())) { result = tempResult; highWaterMark = workingPos; } workingPos = pos; } } } #ifdef RBNF_DEBUG fprintf(stderr, " continue other with text '"); dumpUS(stderr, text); fprintf(stderr, "' hwm: %d\n", highWaterMark.getIndex()); #endif // finally, go through the regular rules one at a time. We start // at the end of the list because we want to try matching the most // sigificant rule first (this helps ensure that we parse // "five thousand three hundred six" as // "(five thousand) (three hundred) (six)" rather than // "((five thousand three) hundred) (six)"). Skip rules whose // base values are higher than the upper bound (again, this helps // limit ambiguity by making sure the rules that match a rule's // are less significant than the rule containing the substitutions)/ { llong ub(upperBound); #ifdef RBNF_DEBUG { char ubstr[64]; ub.lltoa(ubstr, 64); fprintf(stderr, "ub: %g, ll: %s(%x/%x)\n", upperBound, ubstr, ub.hi, ub.lo); } #endif for (int32_t i = rules.size(); --i >= 0 && highWaterMark.getIndex() < text.length();) { if ((!fIsFractionRuleSet) && (rules[i]->getBaseValue() >= ub)) { continue; } Formattable tempResult; UBool success = rules[i]->doParse(text, workingPos, fIsFractionRuleSet, upperBound, tempResult); if (success && workingPos.getIndex() > highWaterMark.getIndex()) { result = tempResult; highWaterMark = workingPos; } workingPos = pos; } } #ifdef RBNF_DEBUG fprintf(stderr, " exit\n"); #endif // finally, update the parse postion we were passed to point to the // first character we didn't use, and return the result that // corresponds to that string of characters pos = highWaterMark; return 1; } void NFRuleSet::appendRules(UnicodeString& result) const { // the rule set name goes first... result.append(name); result.append(gColon); result.append(gLineFeed); // followed by the regular rules... for (uint32_t i = 0; i < rules.size(); i++) { result.append(gFourSpaces); rules[i]->appendRuleText(result); result.append(gLineFeed); } // followed by the special rules (if they exist) if (negativeNumberRule) { result.append(gFourSpaces); negativeNumberRule->appendRuleText(result); result.append(gLineFeed); } { for (uint32_t i = 0; i < 3; ++i) { if (fractionRules[i]) { result.append(gFourSpaces); fractionRules[i]->appendRuleText(result); result.append(gLineFeed); } } } } U_NAMESPACE_END