Check in the pristine copy of ICU 4.6...

icu46/source/i18n/nfsubs.cpp

+/*
+******************************************************************************
+*   Copyright (C) 1997-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+******************************************************************************
+*   file name:  nfsubs.cpp
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+* Modification history
+* Date        Name      Comments
+* 10/11/2001  Doug      Ported from ICU4J
+*/
+
+#include <stdio.h>
+#include <typeinfo>  // for 'typeid' to work
+
+#include "nfsubs.h"
+#include "digitlst.h"
+
+#if U_HAVE_RBNF
+
+static const UChar gLessThan = 0x003c;
+static const UChar gEquals = 0x003d;
+static const UChar gGreaterThan = 0x003e;
+static const UChar gPercent = 0x0025;
+static const UChar gPound = 0x0023;
+static const UChar gZero = 0x0030;
+static const UChar gSpace = 0x0020;
+
+static const UChar gEqualsEquals[] =
+{
+    0x3D, 0x3D, 0
+}; /* "==" */
+static const UChar gGreaterGreaterGreaterThan[] =
+{
+    0x3E, 0x3E, 0x3E, 0
+}; /* ">>>" */
+static const UChar gGreaterGreaterThan[] =
+{
+    0x3E, 0x3E, 0
+}; /* ">>" */
+
+U_NAMESPACE_BEGIN
+
+class SameValueSubstitution : public NFSubstitution {
+public:
+    SameValueSubstitution(int32_t pos,
+        const NFRuleSet* ruleset,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status);
+
+    virtual int64_t transformNumber(int64_t number) const { return number; }
+    virtual double transformNumber(double number) const { return number; }
+    virtual double composeRuleValue(double newRuleValue, double /*oldRuleValue*/) const { return newRuleValue; }
+    virtual double calcUpperBound(double oldUpperBound) const { return oldUpperBound; }
+    virtual UChar tokenChar() const { return (UChar)0x003d; } // '='
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+class MultiplierSubstitution : public NFSubstitution {
+    double divisor;
+    int64_t ldivisor;
+
+public:
+    MultiplierSubstitution(int32_t _pos,
+        double _divisor,
+        const NFRuleSet* _ruleSet,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status)
+        : NFSubstitution(_pos, _ruleSet, formatter, description, status), divisor(_divisor)
+    {
+        ldivisor = util64_fromDouble(divisor);
+        if (divisor == 0) {
+            status = U_PARSE_ERROR;
+        }
+    }
+
+    virtual void setDivisor(int32_t radix, int32_t exponent, UErrorCode& status) { 
+        divisor = uprv_pow(radix, exponent);
+        ldivisor = util64_fromDouble(divisor);
+
+        if(divisor == 0) {
+            status = U_PARSE_ERROR;
+        }
+    }
+
+    virtual UBool operator==(const NFSubstitution& rhs) const;
+
+    virtual int64_t transformNumber(int64_t number) const {
+        return number / ldivisor;
+    }
+
+    virtual double transformNumber(double number) const {
+        if (getRuleSet()) {
+            return uprv_floor(number / divisor);
+        } else {
+            return number/divisor;
+        }
+    }
+
+    virtual double composeRuleValue(double newRuleValue, double /*oldRuleValue*/) const {
+        return newRuleValue * divisor;
+    }
+
+    virtual double calcUpperBound(double /*oldUpperBound*/) const { return divisor; }
+
+    virtual UChar tokenChar() const { return (UChar)0x003c; } // '<'
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+class ModulusSubstitution : public NFSubstitution {
+    double divisor;
+    int64_t  ldivisor;
+    const NFRule* ruleToUse;
+public:
+    ModulusSubstitution(int32_t pos,
+        double _divisor,
+        const NFRule* rulePredecessor,
+        const NFRuleSet* ruleSet,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status);
+
+    virtual void setDivisor(int32_t radix, int32_t exponent, UErrorCode& status) { 
+        divisor = uprv_pow(radix, exponent);
+        ldivisor = util64_fromDouble(divisor);
+
+        if (divisor == 0) {
+            status = U_PARSE_ERROR;
+        }
+    }
+
+    virtual UBool operator==(const NFSubstitution& rhs) const;
+
+    virtual void doSubstitution(int64_t number, UnicodeString& toInsertInto, int32_t pos) const;
+    virtual void doSubstitution(double number, UnicodeString& toInsertInto, int32_t pos) const;
+
+    virtual int64_t transformNumber(int64_t number) const { return number % ldivisor; }
+    virtual double transformNumber(double number) const { return uprv_fmod(number, divisor); }
+
+    virtual UBool doParse(const UnicodeString& text, 
+        ParsePosition& parsePosition,
+        double baseValue,
+        double upperBound,
+        UBool lenientParse,
+        Formattable& result) const;
+
+    virtual double composeRuleValue(double newRuleValue, double oldRuleValue) const {
+        return oldRuleValue - uprv_fmod(oldRuleValue, divisor) + newRuleValue;
+    }
+
+    virtual double calcUpperBound(double /*oldUpperBound*/) const { return divisor; }
+
+    virtual UBool isModulusSubstitution() const { return TRUE; }
+
+    virtual UChar tokenChar() const { return (UChar)0x003e; } // '>'
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+class IntegralPartSubstitution : public NFSubstitution {
+public:
+    IntegralPartSubstitution(int32_t _pos,
+        const NFRuleSet* _ruleSet,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status)
+        : NFSubstitution(_pos, _ruleSet, formatter, description, status) {}
+
+    virtual int64_t transformNumber(int64_t number) const { return number; }
+    virtual double transformNumber(double number) const { return uprv_floor(number); }
+    virtual double composeRuleValue(double newRuleValue, double oldRuleValue) const { return newRuleValue + oldRuleValue; }
+    virtual double calcUpperBound(double /*oldUpperBound*/) const { return DBL_MAX; }
+    virtual UChar tokenChar() const { return (UChar)0x003c; } // '<'
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+class FractionalPartSubstitution : public NFSubstitution {
+    UBool byDigits;
+    UBool useSpaces;
+    enum { kMaxDecimalDigits = 8 };
+public:
+    FractionalPartSubstitution(int32_t pos,
+        const NFRuleSet* ruleSet,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status);
+
+    virtual UBool operator==(const NFSubstitution& rhs) const;
+
+    virtual void doSubstitution(double number, UnicodeString& toInsertInto, int32_t pos) const;
+    virtual void doSubstitution(int64_t /*number*/, UnicodeString& /*toInsertInto*/, int32_t /*_pos*/) const {}
+    virtual int64_t transformNumber(int64_t /*number*/) const { return 0; }
+    virtual double transformNumber(double number) const { return number - uprv_floor(number); }
+
+    virtual UBool doParse(const UnicodeString& text,
+        ParsePosition& parsePosition,
+        double baseValue,
+        double upperBound,
+        UBool lenientParse,
+        Formattable& result) const;
+
+    virtual double composeRuleValue(double newRuleValue, double oldRuleValue) const { return newRuleValue + oldRuleValue; }
+    virtual double calcUpperBound(double /*oldUpperBound*/) const { return 0.0; }
+    virtual UChar tokenChar() const { return (UChar)0x003e; } // '>'
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+class AbsoluteValueSubstitution : public NFSubstitution {
+public:
+    AbsoluteValueSubstitution(int32_t _pos,
+        const NFRuleSet* _ruleSet,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status)
+        : NFSubstitution(_pos, _ruleSet, formatter, description, status) {}
+
+    virtual int64_t transformNumber(int64_t number) const { return number >= 0 ? number : -number; }
+    virtual double transformNumber(double number) const { return uprv_fabs(number); }
+    virtual double composeRuleValue(double newRuleValue, double /*oldRuleValue*/) const { return -newRuleValue; }
+    virtual double calcUpperBound(double /*oldUpperBound*/) const { return DBL_MAX; }
+    virtual UChar tokenChar() const { return (UChar)0x003e; } // '>'
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+class NumeratorSubstitution : public NFSubstitution {
+    double denominator;
+    int64_t ldenominator;
+    UBool withZeros;
+public:
+    static inline UnicodeString fixdesc(const UnicodeString& desc) {
+        if (desc.endsWith(LTLT, 2)) {
+            UnicodeString result(desc, 0, desc.length()-1);
+            return result;
+        }
+        return desc;
+    }
+    NumeratorSubstitution(int32_t _pos,
+        double _denominator,
+        const NFRuleSet* _ruleSet,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status)
+        : NFSubstitution(_pos, _ruleSet, formatter, fixdesc(description), status), denominator(_denominator) 
+    {
+        ldenominator = util64_fromDouble(denominator);
+        withZeros = description.endsWith(LTLT, 2);
+    }
+
+    virtual UBool operator==(const NFSubstitution& rhs) const;
+
+    virtual int64_t transformNumber(int64_t number) const { return number * ldenominator; }
+    virtual double transformNumber(double number) const { return uprv_round(number * denominator); }
+
+    virtual void doSubstitution(int64_t /*number*/, UnicodeString& /*toInsertInto*/, int32_t /*_pos*/) const {}
+    virtual void doSubstitution(double number, UnicodeString& toInsertInto, int32_t pos) const;
+    virtual UBool doParse(const UnicodeString& text, 
+        ParsePosition& parsePosition,
+        double baseValue,
+        double upperBound,
+        UBool /*lenientParse*/,
+        Formattable& result) const;
+
+    virtual double composeRuleValue(double newRuleValue, double oldRuleValue) const { return newRuleValue / oldRuleValue; }
+    virtual double calcUpperBound(double /*oldUpperBound*/) const { return denominator; }
+    virtual UChar tokenChar() const { return (UChar)0x003c; } // '<'
+private:
+    static const UChar LTLT[2];
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+class NullSubstitution : public NFSubstitution {
+public:
+    NullSubstitution(int32_t _pos,
+        const NFRuleSet* _ruleSet,
+        const RuleBasedNumberFormat* formatter,
+        const UnicodeString& description,
+        UErrorCode& status)
+        : NFSubstitution(_pos, _ruleSet, formatter, description, status) {}
+
+    virtual void toString(UnicodeString& /*result*/) const {}
+    virtual void doSubstitution(double /*number*/, UnicodeString& /*toInsertInto*/, int32_t /*_pos*/) const {}
+    virtual void doSubstitution(int64_t /*number*/, UnicodeString& /*toInsertInto*/, int32_t /*_pos*/) const {}
+    virtual int64_t transformNumber(int64_t /*number*/) const { return 0; }
+    virtual double transformNumber(double /*number*/) const { return 0; }
+    virtual UBool doParse(const UnicodeString& /*text*/,
+        ParsePosition& /*parsePosition*/, 
+        double baseValue,
+        double /*upperBound*/,
+        UBool /*lenientParse*/,
+        Formattable& result) const
+    { result.setDouble(baseValue); return TRUE; }
+    virtual double composeRuleValue(double /*newRuleValue*/, double /*oldRuleValue*/) const { return 0.0; } // never called
+    virtual double calcUpperBound(double /*oldUpperBound*/) const { return 0; } // never called
+    virtual UBool isNullSubstitution() const { return TRUE; }
+    virtual UChar tokenChar() const { return (UChar)0x0020; } // ' ' never called
+
+public:
+    static UClassID getStaticClassID(void);
+    virtual UClassID getDynamicClassID(void) const;
+};
+
+NFSubstitution*
+NFSubstitution::makeSubstitution(int32_t pos,
+                                 const NFRule* rule,
+                                 const NFRule* predecessor,
+                                 const NFRuleSet* ruleSet,
+                                 const RuleBasedNumberFormat* formatter,
+                                 const UnicodeString& description,
+                                 UErrorCode& status)
+{
+    // if the description is empty, return a NullSubstitution
+    if (description.length() == 0) {
+        return new NullSubstitution(pos, ruleSet, formatter, description, status);
+    }
+
+    switch (description.charAt(0)) {
+        // if the description begins with '<'...
+    case gLessThan:
+        // throw an exception if the rule is a negative number
+        // rule
+        if (rule->getBaseValue() == NFRule::kNegativeNumberRule) {
+            // throw new IllegalArgumentException("<< not allowed in negative-number rule");
+            status = U_PARSE_ERROR;
+            return NULL;
+        }
+
+        // if the rule is a fraction rule, return an
+        // IntegralPartSubstitution
+        else if (rule->getBaseValue() == NFRule::kImproperFractionRule
+            || rule->getBaseValue() == NFRule::kProperFractionRule
+            || rule->getBaseValue() == NFRule::kMasterRule) {
+            return new IntegralPartSubstitution(pos, ruleSet, formatter, description, status);
+        }
+
+        // if the rule set containing the rule is a fraction
+        // rule set, return a NumeratorSubstitution
+        else if (ruleSet->isFractionRuleSet()) {
+            return new NumeratorSubstitution(pos, (double)rule->getBaseValue(),
+                formatter->getDefaultRuleSet(), formatter, description, status);
+        }
+
+        // otherwise, return a MultiplierSubstitution
+        else {
+            return new MultiplierSubstitution(pos, rule->getDivisor(), ruleSet,
+                formatter, description, status);
+        }
+
+        // if the description begins with '>'...
+    case gGreaterThan:
+        // if the rule is a negative-number rule, return
+        // an AbsoluteValueSubstitution
+        if (rule->getBaseValue() == NFRule::kNegativeNumberRule) {
+            return new AbsoluteValueSubstitution(pos, ruleSet, formatter, description, status);
+        }
+
+        // if the rule is a fraction rule, return a
+        // FractionalPartSubstitution
+        else if (rule->getBaseValue() == NFRule::kImproperFractionRule
+            || rule->getBaseValue() == NFRule::kProperFractionRule
+            || rule->getBaseValue() == NFRule::kMasterRule) {
+            return new FractionalPartSubstitution(pos, ruleSet, formatter, description, status);
+        }
+
+        // if the rule set owning the rule is a fraction rule set,
+        // throw an exception
+        else if (ruleSet->isFractionRuleSet()) {
+            // throw new IllegalArgumentException(">> not allowed in fraction rule set");
+            status = U_PARSE_ERROR;
+            return NULL;
+        }
+
+        // otherwise, return a ModulusSubstitution
+        else {
+            return new ModulusSubstitution(pos, rule->getDivisor(), predecessor,
+                ruleSet, formatter, description, status);
+        }
+
+        // if the description begins with '=', always return a
+        // SameValueSubstitution
+    case gEquals:
+        return new SameValueSubstitution(pos, ruleSet, formatter, description, status);
+
+        // and if it's anything else, throw an exception
+    default:
+        // throw new IllegalArgumentException("Illegal substitution character");
+        status = U_PARSE_ERROR;
+    }
+    return NULL;
+}
+
+NFSubstitution::NFSubstitution(int32_t _pos,
+                               const NFRuleSet* _ruleSet,
+                               const RuleBasedNumberFormat* formatter,
+                               const UnicodeString& description,
+                               UErrorCode& status)
+                               : pos(_pos), ruleSet(NULL), numberFormat(NULL)
+{
+    // the description should begin and end with the same character.
+    // If it doesn't that's a syntax error.  Otherwise,
+    // makeSubstitution() was the only thing that needed to know
+    // about these characters, so strip them off
+    UnicodeString workingDescription(description);
+    if (description.length() >= 2
+        && description.charAt(0) == description.charAt(description.length() - 1))
+    {
+        workingDescription.remove(description.length() - 1, 1);
+        workingDescription.remove(0, 1);
+    }
+    else if (description.length() != 0) {
+        // throw new IllegalArgumentException("Illegal substitution syntax");
+        status = U_PARSE_ERROR;
+        return;
+    }
+
+    // if the description was just two paired token characters
+    // (i.e., "<<" or ">>"), it uses the rule set it belongs to to
+    // format its result
+    if (workingDescription.length() == 0) {
+        this->ruleSet = _ruleSet;
+    }
+    // if the description contains a rule set name, that's the rule
+    // set we use to format the result: get a reference to the
+    // names rule set
+    else if (workingDescription.charAt(0) == gPercent) {
+        this->ruleSet = formatter->findRuleSet(workingDescription, status);
+    }
+    // if the description begins with 0 or #, treat it as a
+    // DecimalFormat pattern, and initialize a DecimalFormat with
+    // that pattern (then set it to use the DecimalFormatSymbols
+    // belonging to our formatter)
+    else if (workingDescription.charAt(0) == gPound || workingDescription.charAt(0) ==gZero) {
+        DecimalFormatSymbols* sym = formatter->getDecimalFormatSymbols();
+        if (!sym) {
+            status = U_MISSING_RESOURCE_ERROR;
+            return;
+        }
+        this->numberFormat = new DecimalFormat(workingDescription, *sym, status);
+        /* test for NULL */
+        if (this->numberFormat == 0) {
+            status = U_MEMORY_ALLOCATION_ERROR;
+            return;
+        }
+        if (U_FAILURE(status)) {
+            delete (DecimalFormat*)this->numberFormat;
+            this->numberFormat = NULL;
+            return;
+        }
+        // this->numberFormat->setDecimalFormatSymbols(formatter->getDecimalFormatSymbols());
+    }
+    // if the description is ">>>", this substitution bypasses the
+    // usual rule-search process and always uses the rule that precedes
+    // it in its own rule set's rule list (this is used for place-value
+    // notations: formats where you want to see a particular part of
+    // a number even when it's 0)
+    else if (workingDescription.charAt(0) == gGreaterThan) {
+        // this causes problems when >>> is used in a frationalPartSubstitution
+        // this->ruleSet = NULL;
+        this->ruleSet = _ruleSet;
+        this->numberFormat = NULL;
+    }
+    // and of the description is none of these things, it's a syntax error
+    else {
+        // throw new IllegalArgumentException("Illegal substitution syntax");
+        status = U_PARSE_ERROR;
+    }
+}
+
+NFSubstitution::~NFSubstitution()
+{
+  // cast away const
+  delete (NumberFormat*)numberFormat; numberFormat = NULL;
+}
+
+/**
+ * Set's the substitution's divisor.  Used by NFRule.setBaseValue().
+ * A no-op for all substitutions except multiplier and modulus
+ * substitutions.
+ * @param radix The radix of the divisor
+ * @param exponent The exponent of the divisor
+ */
+void
+NFSubstitution::setDivisor(int32_t /*radix*/, int32_t /*exponent*/, UErrorCode& /*status*/) {
+  // a no-op for all substitutions except multiplier and modulus substitutions
+}
+
+
+//-----------------------------------------------------------------------
+// boilerplate
+//-----------------------------------------------------------------------
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(NFSubstitution)
+
+/**
+ * Compares two substitutions for equality
+ * @param The substitution to compare this one to
+ * @return true if the two substitutions are functionally equivalent
+ */
+UBool
+NFSubstitution::operator==(const NFSubstitution& rhs) const
+{
+  // compare class and all of the fields all substitutions have
+  // in common
+  // this should be called by subclasses before their own equality tests
+  return typeid(*this) == typeid(rhs)
+  && pos == rhs.pos
+  && (ruleSet == NULL) == (rhs.ruleSet == NULL)
+  // && ruleSet == rhs.ruleSet causes circularity, other checks to make instead?
+  && (numberFormat == NULL
+      ? (rhs.numberFormat == NULL)
+      : (*numberFormat == *rhs.numberFormat));
+}
+
+/**
+ * Returns a textual description of the substitution
+ * @return A textual description of the substitution.  This might
+ * not be identical to the description it was created from, but
+ * it'll produce the same result.
+ */
+void
+NFSubstitution::toString(UnicodeString& text) const
+{
+  // use tokenChar() to get the character at the beginning and
+  // end of the substitutin token.  In between them will go
+  // either the name of the rule set it uses, or the pattern of
+  // the DecimalFormat it uses
+  text.remove();
+  text.append(tokenChar());
+
+  UnicodeString temp;
+  if (ruleSet != NULL) {
+    ruleSet->getName(temp);
+  } else if (numberFormat != NULL) {
+    numberFormat->toPattern(temp);
+  }
+  text.append(temp);
+  text.append(tokenChar());
+}
+
+//-----------------------------------------------------------------------
+// formatting
+//-----------------------------------------------------------------------
+
+/**
+ * Performs a mathematical operation on the number, formats it using
+ * either ruleSet or decimalFormat, and inserts the result into
+ * toInsertInto.
+ * @param number The number being formatted.
+ * @param toInsertInto The string we insert the result into
+ * @param pos The position in toInsertInto where the owning rule's
+ * rule text begins (this value is added to this substitution's
+ * position to determine exactly where to insert the new text)
+ */
+void
+NFSubstitution::doSubstitution(int64_t number, UnicodeString& toInsertInto, int32_t _pos) const
+{
+    if (ruleSet != NULL) {
+        // perform a transformation on the number that is dependent
+        // on the type of substitution this is, then just call its
+        // rule set's format() method to format the result
+        ruleSet->format(transformNumber(number), toInsertInto, _pos + this->pos);
+    } else if (numberFormat != NULL) {
+        // or perform the transformation on the number (preserving
+        // the result's fractional part if the formatter it set
+        // to show it), then use that formatter's format() method
+        // to format the result
+        double numberToFormat = transformNumber((double)number);
+        if (numberFormat->getMaximumFractionDigits() == 0) {
+            numberToFormat = uprv_floor(numberToFormat);
+        }
+
+        UnicodeString temp;
+        numberFormat->format(numberToFormat, temp);
+        toInsertInto.insert(_pos + this->pos, temp);
+    }
+}
+
+/**
+ * Performs a mathematical operation on the number, formats it using
+ * either ruleSet or decimalFormat, and inserts the result into
+ * toInsertInto.
+ * @param number The number being formatted.
+ * @param toInsertInto The string we insert the result into
+ * @param pos The position in toInsertInto where the owning rule's
+ * rule text begins (this value is added to this substitution's
+ * position to determine exactly where to insert the new text)
+ */
+void
+NFSubstitution::doSubstitution(double number, UnicodeString& toInsertInto, int32_t _pos) const {
+    // perform a transformation on the number being formatted that
+    // is dependent on the type of substitution this is
+    double numberToFormat = transformNumber(number);
+
+    // if the result is an integer, from here on out we work in integer
+    // space (saving time and memory and preserving accuracy)
+    if (numberToFormat == uprv_floor(numberToFormat) && ruleSet != NULL) {
+        ruleSet->format(util64_fromDouble(numberToFormat), toInsertInto, _pos + this->pos);
+
+        // if the result isn't an integer, then call either our rule set's
+        // format() method or our DecimalFormat's format() method to
+        // format the result
+    } else {
+        if (ruleSet != NULL) {
+            ruleSet->format(numberToFormat, toInsertInto, _pos + this->pos);
+        } else if (numberFormat != NULL) {
+            UnicodeString temp;
+            numberFormat->format(numberToFormat, temp);
+            toInsertInto.insert(_pos + this->pos, temp);
+        }
+    }
+}
+
+
+    //-----------------------------------------------------------------------
+    // parsing
+    //-----------------------------------------------------------------------
+
+#ifdef RBNF_DEBUG
+#include <stdio.h>
+#endif
+
+/**
+ * Parses a string using the rule set or DecimalFormat belonging
+ * to this substitution.  If there's a match, a mathematical
+ * operation (the inverse of the one used in formatting) is
+ * performed on the result of the parse and the value passed in
+ * and returned as the result.  The parse position is updated to
+ * point to the first unmatched character in the string.
+ * @param text The string to parse
+ * @param parsePosition On entry, ignored, but assumed to be 0.
+ * On exit, this is updated to point to the first unmatched
+ * character (or 0 if the substitution didn't match)
+ * @param baseValue A partial parse result that should be
+ * combined with the result of this parse
+ * @param upperBound When searching the rule set for a rule
+ * matching the string passed in, only rules with base values
+ * lower than this are considered
+ * @param lenientParse If true and matching against rules fails,
+ * the substitution will also try matching the text against
+ * numerals using a default-costructed NumberFormat.  If false,
+ * no extra work is done.  (This value is false whenever the
+ * formatter isn't in lenient-parse mode, but is also false
+ * under some conditions even when the formatter _is_ in
+ * lenient-parse mode.)
+ * @return If there's a match, this is the result of composing
+ * baseValue with whatever was returned from matching the
+ * characters.  This will be either a Long or a Double.  If there's
+ * no match this is new Long(0) (not null), and parsePosition
+ * is left unchanged.
+ */
+UBool
+NFSubstitution::doParse(const UnicodeString& text,
+                        ParsePosition& parsePosition,
+                        double baseValue,
+                        double upperBound,
+                        UBool lenientParse,
+                        Formattable& result) const
+{
+#ifdef RBNF_DEBUG
+    fprintf(stderr, "<nfsubs> %x bv: %g ub: %g\n", this, baseValue, upperBound);
+#endif
+    // figure out the highest base value a rule can have and match
+    // the text being parsed (this varies according to the type of
+    // substitutions: multiplier, modulus, and numerator substitutions
+    // restrict the search to rules with base values lower than their
+    // own; same-value substitutions leave the upper bound wherever
+    // it was, and the others allow any rule to match
+    upperBound = calcUpperBound(upperBound);
+
+    // use our rule set to parse the text.  If that fails and
+    // lenient parsing is enabled (this is always false if the
+    // formatter's lenient-parsing mode is off, but it may also
+    // be false even when the formatter's lenient-parse mode is
+    // on), then also try parsing the text using a default-
+    // constructed NumberFormat
+    if (ruleSet != NULL) {
+        ruleSet->parse(text, parsePosition, upperBound, result);
+        if (lenientParse && !ruleSet->isFractionRuleSet() && parsePosition.getIndex() == 0) {
+            UErrorCode status = U_ZERO_ERROR;
+            NumberFormat* fmt = NumberFormat::createInstance(status);
+            if (U_SUCCESS(status)) {
+                fmt->parse(text, result, parsePosition);
+            }
+            delete fmt;
+        }
+
+        // ...or use our DecimalFormat to parse the text
+    } else if (numberFormat != NULL) {
+        numberFormat->parse(text, result, parsePosition);
+    }
+
+    // if the parse was successful, we've already advanced the caller's
+    // parse position (this is the one function that doesn't have one
+    // of its own).  Derive a parse result and return it as a Long,
+    // if possible, or a Double
+    if (parsePosition.getIndex() != 0) {
+        UErrorCode status = U_ZERO_ERROR;
+        double tempResult = result.getDouble(status);
+
+        // composeRuleValue() produces a full parse result from
+        // the partial parse result passed to this function from
+        // the caller (this is either the owning rule's base value
+        // or the partial result obtained from composing the
+        // owning rule's base value with its other substitution's
+        // parse result) and the partial parse result obtained by
+        // matching the substitution (which will be the same value
+        // the caller would get by parsing just this part of the
+        // text with RuleBasedNumberFormat.parse() ).  How the two
+        // values are used to derive the full parse result depends
+        // on the types of substitutions: For a regular rule, the
+        // ultimate result is its multiplier substitution's result
+        // times the rule's divisor (or the rule's base value) plus
+        // the modulus substitution's result (which will actually
+        // supersede part of the rule's base value).  For a negative-
+        // number rule, the result is the negative of its substitution's
+        // result.  For a fraction rule, it's the sum of its two
+        // substitution results.  For a rule in a fraction rule set,
+        // it's the numerator substitution's result divided by
+        // the rule's base value.  Results from same-value substitutions
+        // propagate back upard, and null substitutions don't affect
+        // the result.
+        tempResult = composeRuleValue(tempResult, baseValue);
+        result.setDouble(tempResult);
+        return TRUE;
+        // if the parse was UNsuccessful, return 0
+    } else {
+        result.setLong(0);
+        return FALSE;
+    }
+}
+
+UBool
+NFSubstitution::isNullSubstitution() const {
+    return FALSE;
+}
+
+    /**
+     * Returns true if this is a modulus substitution.  (We didn't do this
+     * with instanceof partially because it causes source files to
+     * proliferate and partially because we have to port this to C++.)
+     * @return true if this object is an instance of ModulusSubstitution
+     */
+UBool
+NFSubstitution::isModulusSubstitution() const {
+    return FALSE;
+}
+
+//===================================================================
+// SameValueSubstitution
+//===================================================================
+
+/**
+ * A substitution that passes the value passed to it through unchanged.
+ * Represented by == in rule descriptions.
+ */
+SameValueSubstitution::SameValueSubstitution(int32_t _pos,
+                        const NFRuleSet* _ruleSet,
+                        const RuleBasedNumberFormat* formatter,
+                        const UnicodeString& description,
+                        UErrorCode& status)
+: NFSubstitution(_pos, _ruleSet, formatter, description, status)
+{
+    if (description == gEqualsEquals) {
+        // throw new IllegalArgumentException("== is not a legal token");
+        status = U_PARSE_ERROR;
+    }
+}
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(SameValueSubstitution)
+
+//===================================================================
+// MultiplierSubstitution
+//===================================================================
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(MultiplierSubstitution)
+
+UBool MultiplierSubstitution::operator==(const NFSubstitution& rhs) const
+{
+    return NFSubstitution::operator==(rhs) &&
+        divisor == ((const MultiplierSubstitution*)&rhs)->divisor;
+}
+
+
+//===================================================================
+// ModulusSubstitution
+//===================================================================
+
+/**
+ * A substitution that divides the number being formatted by the its rule's
+ * divisor and formats the remainder.  Represented by "&gt;&gt;" in a
+ * regular rule.
+ */
+ModulusSubstitution::ModulusSubstitution(int32_t _pos,
+                                         double _divisor,
+                                         const NFRule* predecessor,
+                                         const NFRuleSet* _ruleSet,
+                                         const RuleBasedNumberFormat* formatter,
+                                         const UnicodeString& description,
+                                         UErrorCode& status)
+ : NFSubstitution(_pos, _ruleSet, formatter, description, status)
+ , divisor(_divisor)
+ , ruleToUse(NULL)
+{
+  ldivisor = util64_fromDouble(_divisor);
+
+  // the owning rule's divisor controls the behavior of this
+  // substitution: rather than keeping a backpointer to the rule,
+  // we keep a copy of the divisor
+
+  if (ldivisor == 0) {
+      status = U_PARSE_ERROR;
+  }
+
+  if (description == gGreaterGreaterGreaterThan) {
+    // the >>> token doesn't alter how this substituion calculates the
+    // values it uses for formatting and parsing, but it changes
+    // what's done with that value after it's obtained: >>> short-
+    // circuits the rule-search process and goes straight to the
+    // specified rule to format the substitution value
+    ruleToUse = predecessor;
+  }
+}
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ModulusSubstitution)
+
+UBool ModulusSubstitution::operator==(const NFSubstitution& rhs) const
+{
+  return NFSubstitution::operator==(rhs) &&
+  divisor == ((const ModulusSubstitution*)&rhs)->divisor &&
+  ruleToUse == ((const ModulusSubstitution*)&rhs)->ruleToUse;
+}
+
+//-----------------------------------------------------------------------
+// formatting
+//-----------------------------------------------------------------------
+
+
+/**
+ * If this is a &gt;&gt;&gt; substitution, use ruleToUse to fill in
+ * the substitution.  Otherwise, just use the superclass function.
+ * @param number The number being formatted
+ * @toInsertInto The string to insert the result of this substitution
+ * into
+ * @param pos The position of the rule text in toInsertInto
+ */
+void
+ModulusSubstitution::doSubstitution(int64_t number, UnicodeString& toInsertInto, int32_t _pos) const
+{
+    // if this isn't a >>> substitution, just use the inherited version
+    // of this function (which uses either a rule set or a DecimalFormat
+    // to format its substitution value)
+    if (ruleToUse == NULL) {
+        NFSubstitution::doSubstitution(number, toInsertInto, _pos);
+
+        // a >>> substitution goes straight to a particular rule to
+        // format the substitution value
+    } else {
+        int64_t numberToFormat = transformNumber(number);
+        ruleToUse->doFormat(numberToFormat, toInsertInto, _pos + getPos());
+    }
+}
+
+/**
+* If this is a &gt;&gt;&gt; substitution, use ruleToUse to fill in
+* the substitution.  Otherwise, just use the superclass function.
+* @param number The number being formatted
+* @toInsertInto The string to insert the result of this substitution
+* into
+* @param pos The position of the rule text in toInsertInto
+*/
+void
+ModulusSubstitution::doSubstitution(double number, UnicodeString& toInsertInto, int32_t _pos) const
+{
+    // if this isn't a >>> substitution, just use the inherited version
+    // of this function (which uses either a rule set or a DecimalFormat
+    // to format its substitution value)
+    if (ruleToUse == NULL) {
+        NFSubstitution::doSubstitution(number, toInsertInto, _pos);
+
+        // a >>> substitution goes straight to a particular rule to
+        // format the substitution value
+    } else {
+        double numberToFormat = transformNumber(number);
+
+        ruleToUse->doFormat(numberToFormat, toInsertInto, _pos + getPos());
+    }
+}
+
+//-----------------------------------------------------------------------
+// parsing
+//-----------------------------------------------------------------------
+
+/**
+ * If this is a &gt;&gt;&gt; substitution, match only against ruleToUse.
+ * Otherwise, use the superclass function.
+ * @param text The string to parse
+ * @param parsePosition Ignored on entry, updated on exit to point to
+ * the first unmatched character.
+ * @param baseValue The partial parse result prior to calling this
+ * routine.
+ */
+UBool
+ModulusSubstitution::doParse(const UnicodeString& text,
+                             ParsePosition& parsePosition,
+                             double baseValue,
+                             double upperBound,
+                             UBool lenientParse,
+                             Formattable& result) const
+{
+    // if this isn't a >>> substitution, we can just use the
+    // inherited parse() routine to do the parsing
+    if (ruleToUse == NULL) {
+        return NFSubstitution::doParse(text, parsePosition, baseValue, upperBound, lenientParse, result);
+
+        // but if it IS a >>> substitution, we have to do it here: we
+        // use the specific rule's doParse() method, and then we have to
+        // do some of the other work of NFRuleSet.parse()
+    } else {
+        ruleToUse->doParse(text, parsePosition, FALSE, upperBound, result);
+
+        if (parsePosition.getIndex() != 0) {
+            UErrorCode status = U_ZERO_ERROR;
+            double tempResult = result.getDouble(status);
+            tempResult = composeRuleValue(tempResult, baseValue);
+            result.setDouble(tempResult);
+        }
+
+        return TRUE;
+    }
+}
+
+
+//===================================================================
+// IntegralPartSubstitution
+//===================================================================
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IntegralPartSubstitution)
+
+
+//===================================================================
+// FractionalPartSubstitution
+//===================================================================
+
+
+    /**
+     * Constructs a FractionalPartSubstitution.  This object keeps a flag
+     * telling whether it should format by digits or not.  In addition,
+     * it marks the rule set it calls (if any) as a fraction rule set.
+     */
+FractionalPartSubstitution::FractionalPartSubstitution(int32_t _pos,
+                             const NFRuleSet* _ruleSet,
+                             const RuleBasedNumberFormat* formatter,
+                             const UnicodeString& description,
+                             UErrorCode& status)
+ : NFSubstitution(_pos, _ruleSet, formatter, description, status)
+ , byDigits(FALSE)
+ , useSpaces(TRUE)
+
+{
+    // akk, ruleSet can change in superclass constructor
+    if (description == gGreaterGreaterThan ||
+        description == gGreaterGreaterGreaterThan ||
+        _ruleSet == getRuleSet()) {
+        byDigits = TRUE;
+        if (description == gGreaterGreaterGreaterThan) {
+            useSpaces = FALSE;
+        }
+    } else {
+        // cast away const
+        ((NFRuleSet*)getRuleSet())->makeIntoFractionRuleSet();
+    }
+}
+
+//-----------------------------------------------------------------------
+// formatting
+//-----------------------------------------------------------------------
+
+/**
+ * If in "by digits" mode, fills in the substitution one decimal digit
+ * at a time using the rule set containing this substitution.
+ * Otherwise, uses the superclass function.
+ * @param number The number being formatted
+ * @param toInsertInto The string to insert the result of formatting
+ * the substitution into
+ * @param pos The position of the owning rule's rule text in
+ * toInsertInto
+ */
+void
+FractionalPartSubstitution::doSubstitution(double number, UnicodeString& toInsertInto, int32_t _pos) const
+{
+  // if we're not in "byDigits" mode, just use the inherited
+  // doSubstitution() routine
+  if (!byDigits) {
+    NFSubstitution::doSubstitution(number, toInsertInto, _pos);
+
+    // if we're in "byDigits" mode, transform the value into an integer
+    // by moving the decimal point eight places to the right and
+    // pulling digits off the right one at a time, formatting each digit
+    // as an integer using this substitution's owning rule set
+    // (this is slower, but more accurate, than doing it from the
+    // other end)
+  } else {
+    //          int32_t numberToFormat = (int32_t)uprv_round(transformNumber(number) * uprv_pow(10, kMaxDecimalDigits));
+    //          // this flag keeps us from formatting trailing zeros.  It starts
+    //          // out false because we're pulling from the right, and switches
+    //          // to true the first time we encounter a non-zero digit
+    //          UBool doZeros = FALSE;
+    //          for (int32_t i = 0; i < kMaxDecimalDigits; i++) {
+    //              int64_t digit = numberToFormat % 10;
+    //              if (digit != 0 || doZeros) {
+    //                  if (doZeros && useSpaces) {
+    //                      toInsertInto.insert(_pos + getPos(), gSpace);
+    //                  }
+    //                  doZeros = TRUE;
+    //                  getRuleSet()->format(digit, toInsertInto, _pos + getPos());
+    //              }
+    //              numberToFormat /= 10;
+    //          }
+
+    DigitList dl;
+    dl.set(number);
+    dl.roundFixedPoint(20);     // round to 20 fraction digits.
+    dl.reduce();                // Removes any trailing zeros.
+    
+    UBool pad = FALSE;
+    for (int32_t didx = dl.getCount()-1; didx>=dl.getDecimalAt(); didx--) {
+      // Loop iterates over fraction digits, starting with the LSD.
+      //   include both real digits from the number, and zeros
+      //   to the left of the MSD but to the right of the decimal point.
+      if (pad && useSpaces) {
+        toInsertInto.insert(_pos + getPos(), gSpace);
+      } else {
+        pad = TRUE;
+      }
+      int64_t digit = didx>=0 ? dl.getDigit(didx) - '0' : 0;
+      getRuleSet()->format(digit, toInsertInto, _pos + getPos());
+    }
+
+    if (!pad) {
+      // hack around lack of precision in digitlist. if we would end up with
+      // "foo point" make sure we add a " zero" to the end.
+      getRuleSet()->format((int64_t)0, toInsertInto, _pos + getPos());
+    }
+  }
+}
+
+//-----------------------------------------------------------------------
+// parsing
+//-----------------------------------------------------------------------
+
+/**
+ * If in "by digits" mode, parses the string as if it were a string
+ * of individual digits; otherwise, uses the superclass function.
+ * @param text The string to parse
+ * @param parsePosition Ignored on entry, but updated on exit to point
+ * to the first unmatched character
+ * @param baseValue The partial parse result prior to entering this
+ * function
+ * @param upperBound Only consider rules with base values lower than
+ * this when filling in the substitution
+ * @param lenientParse If true, try matching the text as numerals if
+ * matching as words doesn't work
+ * @return If the match was successful, the current partial parse
+ * result; otherwise new Long(0).  The result is either a Long or
+ * a Double.
+ */
+
+UBool
+FractionalPartSubstitution::doParse(const UnicodeString& text,
+                ParsePosition& parsePosition,
+                double baseValue,
+                double /*upperBound*/,
+                UBool lenientParse,
+                Formattable& resVal) const
+{
+    // if we're not in byDigits mode, we can just use the inherited
+    // doParse()
+    if (!byDigits) {
+        return NFSubstitution::doParse(text, parsePosition, baseValue, 0, lenientParse, resVal);
+
+        // if we ARE in byDigits mode, parse the text one digit at a time
+        // using this substitution's owning rule set (we do this by setting
+        // upperBound to 10 when calling doParse() ) until we reach
+        // nonmatching text
+    } else {
+        UnicodeString workText(text);
+        ParsePosition workPos(1);
+        double result = 0;
+        int32_t digit;
+//          double p10 = 0.1;
+
+        DigitList dl;
+        NumberFormat* fmt = NULL;
+        while (workText.length() > 0 && workPos.getIndex() != 0) {
+            workPos.setIndex(0);
+            Formattable temp;
+            getRuleSet()->parse(workText, workPos, 10, temp);
+            UErrorCode status = U_ZERO_ERROR;
+            digit = temp.getLong(status);
+//            digit = temp.getType() == Formattable::kLong ?
+//               temp.getLong() :
+//            (int32_t)temp.getDouble();
+
+            if (lenientParse && workPos.getIndex() == 0) {
+                if (!fmt) {
+                    status = U_ZERO_ERROR;
+                    fmt = NumberFormat::createInstance(status);
+                    if (U_FAILURE(status)) {
+                        delete fmt;
+                        fmt = NULL;
+                    }
+                }
+                if (fmt) {
+                    fmt->parse(workText, temp, workPos);
+                    digit = temp.getLong(status);
+                }
+            }
+
+            if (workPos.getIndex() != 0) {
+                dl.append((char)('0' + digit));
+//                  result += digit * p10;
+//                  p10 /= 10;
+                parsePosition.setIndex(parsePosition.getIndex() + workPos.getIndex());
+                workText.removeBetween(0, workPos.getIndex());
+                while (workText.length() > 0 && workText.charAt(0) == gSpace) {
+                    workText.removeBetween(0, 1);
+                    parsePosition.setIndex(parsePosition.getIndex() + 1);
+                }
+            }
+        }
+        delete fmt;
+
+        result = dl.getCount() == 0 ? 0 : dl.getDouble();
+        result = composeRuleValue(result, baseValue);
+        resVal.setDouble(result);
+        return TRUE;
+    }
+}
+
+UBool
+FractionalPartSubstitution::operator==(const NFSubstitution& rhs) const
+{
+  return NFSubstitution::operator==(rhs) &&
+  ((const FractionalPartSubstitution*)&rhs)->byDigits == byDigits;
+}
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(FractionalPartSubstitution)
+
+
+//===================================================================
+// AbsoluteValueSubstitution
+//===================================================================
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(AbsoluteValueSubstitution)
+
+//===================================================================
+// NumeratorSubstitution
+//===================================================================
+
+void
+NumeratorSubstitution::doSubstitution(double number, UnicodeString& toInsertInto, int32_t apos) const {
+    // perform a transformation on the number being formatted that
+    // is dependent on the type of substitution this is
+
+    double numberToFormat = transformNumber(number);
+    int64_t longNF = util64_fromDouble(numberToFormat);
+
+    const NFRuleSet* aruleSet = getRuleSet();
+    if (withZeros && aruleSet != NULL) {
+        // if there are leading zeros in the decimal expansion then emit them
+        int64_t nf =longNF;
+        int32_t len = toInsertInto.length();
+        while ((nf *= 10) < denominator) {
+            toInsertInto.insert(apos + getPos(), gSpace);
+            aruleSet->format((int64_t)0, toInsertInto, apos + getPos());
+        }
+        apos += toInsertInto.length() - len;
+    }
+
+    // if the result is an integer, from here on out we work in integer
+    // space (saving time and memory and preserving accuracy)
+    if (numberToFormat == longNF && aruleSet != NULL) {
+        aruleSet->format(longNF, toInsertInto, apos + getPos());
+
+        // if the result isn't an integer, then call either our rule set's
+        // format() method or our DecimalFormat's format() method to
+        // format the result
+    } else {
+        if (aruleSet != NULL) {
+            aruleSet->format(numberToFormat, toInsertInto, apos + getPos());
+        } else {
+            UErrorCode status = U_ZERO_ERROR;
+            UnicodeString temp;
+            getNumberFormat()->format(numberToFormat, temp, status);
+            toInsertInto.insert(apos + getPos(), temp);
+        }
+    }
+}
+
+UBool 
+NumeratorSubstitution::doParse(const UnicodeString& text, 
+                               ParsePosition& parsePosition,
+                               double baseValue,
+                               double upperBound,
+                               UBool /*lenientParse*/,
+                               Formattable& result) const
+{
+    // we don't have to do anything special to do the parsing here,
+    // but we have to turn lenient parsing off-- if we leave it on,
+    // it SERIOUSLY messes up the algorithm
+
+    // if withZeros is true, we need to count the zeros
+    // and use that to adjust the parse result
+    UErrorCode status = U_ZERO_ERROR;
+    int32_t zeroCount = 0;
+    UnicodeString workText(text);
+
+    if (withZeros) {
+        ParsePosition workPos(1);
+        Formattable temp;
+
+        while (workText.length() > 0 && workPos.getIndex() != 0) {
+            workPos.setIndex(0);
+            getRuleSet()->parse(workText, workPos, 1, temp); // parse zero or nothing at all
+            if (workPos.getIndex() == 0) {
+                // we failed, either there were no more zeros, or the number was formatted with digits
+                // either way, we're done
+                break;
+            }
+
+            ++zeroCount;
+            parsePosition.setIndex(parsePosition.getIndex() + workPos.getIndex());
+            workText.remove(0, workPos.getIndex());
+            while (workText.length() > 0 && workText.charAt(0) == gSpace) {
+                workText.remove(0, 1);
+                parsePosition.setIndex(parsePosition.getIndex() + 1);
+            }
+        }
+
+        workText = text;
+        workText.remove(0, (int32_t)parsePosition.getIndex());
+        parsePosition.setIndex(0);
+    }
+
+    // we've parsed off the zeros, now let's parse the rest from our current position
+    NFSubstitution::doParse(workText, parsePosition, withZeros ? 1 : baseValue, upperBound, FALSE, result);
+
+    if (withZeros) {
+        // any base value will do in this case.  is there a way to
+        // force this to not bother trying all the base values?
+
+        // compute the 'effective' base and prescale the value down
+        int64_t n = result.getLong(status); // force conversion!
+        int64_t d = 1;
+        int32_t pow = 0;
+        while (d <= n) {
+            d *= 10;
+            ++pow;
+        }
+        // now add the zeros
+        while (zeroCount > 0) {
+            d *= 10;
+            --zeroCount;
+        }
+        // d is now our true denominator
+        result.setDouble((double)n/(double)d);
+    }
+
+    return TRUE;
+}
+
+UBool
+NumeratorSubstitution::operator==(const NFSubstitution& rhs) const
+{
+    return NFSubstitution::operator==(rhs) &&
+        denominator == ((const NumeratorSubstitution*)&rhs)->denominator;
+}
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(NumeratorSubstitution)
+
+const UChar NumeratorSubstitution::LTLT[] = { 0x003c, 0x003c };
+        
+//===================================================================
+// NullSubstitution
+//===================================================================
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(NullSubstitution)
+
+U_NAMESPACE_END
+
+/* U_HAVE_RBNF */
+#endif
+