tor-browser

choicfmt.h (24563B)

---

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
********************************************************************************
*   Copyright (C) 1997-2013, International Business Machines
*   Corporation and others.  All Rights Reserved.
********************************************************************************
*
* File CHOICFMT.H
*
* Modification History:
*
*   Date        Name        Description
*   02/19/97    aliu        Converted from java.
*   03/20/97    helena      Finished first cut of implementation and got rid
*                           of nextDouble/previousDouble and replaced with
*                           boolean array.
*   4/10/97     aliu        Clean up.  Modified to work on AIX.
*   8/6/97      nos         Removed overloaded constructor, member var 'buffer'.
*   07/22/98    stephen     Removed operator!= (implemented in Format)
********************************************************************************
*/

#ifndef CHOICFMT_H
#define CHOICFMT_H

#include "unicode/utypes.h"

#if U_SHOW_CPLUSPLUS_API

/**
* \file
* \brief C++ API: Choice Format.
*/

#if !UCONFIG_NO_FORMATTING

#include "unicode/fieldpos.h"
#include "unicode/format.h"
#include "unicode/messagepattern.h"
#include "unicode/numfmt.h"
#include "unicode/unistr.h"

#ifndef U_HIDE_DEPRECATED_API

U_NAMESPACE_BEGIN

class MessageFormat;

/**
* ChoiceFormat converts between ranges of numeric values and strings for those ranges.
* The strings must conform to the MessageFormat pattern syntax.
*
* <p><em><code>ChoiceFormat</code> is probably not what you need.
* Please use <code>MessageFormat</code>
* with <code>plural</code> arguments for proper plural selection,
* and <code>select</code> arguments for simple selection among a fixed set of choices!</em></p>
*
* <p>A <code>ChoiceFormat</code> splits
* the real number line \htmlonly<code>-&#x221E;</code> to
* <code>+&#x221E;</code>\endhtmlonly into two
* or more contiguous ranges. Each range is mapped to a
* string.</p>
*
* <p><code>ChoiceFormat</code> was originally intended
* for displaying grammatically correct
* plurals such as &quot;There is one file.&quot; vs. &quot;There are 2 files.&quot;
* <em>However,</em> plural rules for many languages
* are too complex for the capabilities of ChoiceFormat,
* and its requirement of specifying the precise rules for each message
* is unmanageable for translators.</p>
*
* <p>There are two methods of defining a <code>ChoiceFormat</code>; both
* are equivalent.  The first is by using a string pattern. This is the
* preferred method in most cases.  The second method is through direct
* specification of the arrays that logically make up the
* <code>ChoiceFormat</code>.</p>
*
* <p>Note: Typically, choice formatting is done (if done at all) via <code>MessageFormat</code>
* with a <code>choice</code> argument type,
* rather than using a stand-alone <code>ChoiceFormat</code>.</p>
*
* <h5>Patterns and Their Interpretation</h5>
*
* <p>The pattern string defines the range boundaries and the strings for each number range.
* Syntax:
* <pre>
* choiceStyle = number separator message ('|' number separator message)*
* number = normal_number | ['-'] \htmlonly&#x221E;\endhtmlonly (U+221E, infinity)
* normal_number = double value (unlocalized ASCII string)
* separator = less_than | less_than_or_equal
* less_than = '<'
* less_than_or_equal = '#' | \htmlonly&#x2264;\endhtmlonly (U+2264)
* message: see {@link MessageFormat}
* </pre>
* Pattern_White_Space between syntax elements is ignored, except
* around each range's sub-message.</p>
*
* <p>Each numeric sub-range extends from the current range's number
* to the next range's number.
* The number itself is included in its range if a <code>less_than_or_equal</code> sign is used,
* and excluded from its range (and instead included in the previous range)
* if a <code>less_than</code> sign is used.</p>
*
* <p>When a <code>ChoiceFormat</code> is constructed from
* arrays of numbers, closure flags and strings,
* they are interpreted just like
* the sequence of <code>(number separator string)</code> in an equivalent pattern string.
* <code>closure[i]==true</code> corresponds to a <code>less_than</code> separator sign.
* The equivalent pattern string will be constructed automatically.</p>
*
* <p>During formatting, a number is mapped to the first range
* where the number is not greater than the range's upper limit.
* That range's message string is returned. A NaN maps to the very first range.</p>
*
* <p>During parsing, a range is selected for the longest match of
* any range's message. That range's number is returned, ignoring the separator/closure.
* Only a simple string match is performed, without parsing of arguments that
* might be specified in the message strings.</p>
*
* <p>Note that the first range's number is ignored in formatting
* but may be returned from parsing.</p>
*
* <h5>Examples</h5>
*
* <p>Here is an example of two arrays that map the number
* <code>1..7</code> to the English day of the week abbreviations
* <code>Sun..Sat</code>. No closures array is given; this is the same as
* specifying all closures to be <code>false</code>.</p>
*
* <pre>    {1,2,3,4,5,6,7},
*     {&quot;Sun&quot;,&quot;Mon&quot;,&quot;Tue&quot;,&quot;Wed&quot;,&quot;Thur&quot;,&quot;Fri&quot;,&quot;Sat&quot;}</pre>
*
* <p>Here is an example that maps the ranges [-Inf, 1), [1, 1], and (1,
* +Inf] to three strings. That is, the number line is split into three
* ranges: x &lt; 1.0, x = 1.0, and x &gt; 1.0.
* (The round parentheses in the notation above indicate an exclusive boundary,
* like the turned bracket in European notation: [-Inf, 1) == [-Inf, 1[  )</p>
*
* <pre>    {0, 1, 1},
*     {false, false, true},
*     {&quot;no files&quot;, &quot;one file&quot;, &quot;many files&quot;}</pre>
*
* <p>Here is an example that shows formatting and parsing: </p>
*
* \code
*   #include <unicode/choicfmt.h>
*   #include <unicode/unistr.h>
*   #include <iostream.h>
*
*   int main(int argc, char *argv[]) {
*       double limits[] = {1,2,3,4,5,6,7};
*       UnicodeString monthNames[] = {
*           "Sun","Mon","Tue","Wed","Thu","Fri","Sat"};
*       ChoiceFormat fmt(limits, monthNames, 7);
*       UnicodeString str;
*       char buf[256];
*       for (double x = 1.0; x <= 8.0; x += 1.0) {
*           fmt.format(x, str);
*           str.extract(0, str.length(), buf, 256, "");
*           str.truncate(0);
*           cout << x << " -> "
*                << buf << endl;
*       }
*       cout << endl;
*       return 0;
*   }
* \endcode
*
* <p><em>User subclasses are not supported.</em> While clients may write
* subclasses, such code will not necessarily work and will not be
* guaranteed to work stably from release to release.
*
* @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
*/
class U_I18N_API ChoiceFormat: public NumberFormat {
public:
   /**
    * Constructs a new ChoiceFormat from the pattern string.
    *
    * @param pattern   Pattern used to construct object.
    * @param status    Output param to receive success code.  If the
    *                  pattern cannot be parsed, set to failure code.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   ChoiceFormat(const UnicodeString& pattern,
                UErrorCode& status);


   /**
    * Constructs a new ChoiceFormat with the given limits and message strings.
    * All closure flags default to <code>false</code>,
    * equivalent to <code>less_than_or_equal</code> separators.
    *
    * Copies the limits and formats instead of adopting them.
    *
    * @param limits    Array of limit values.
    * @param formats   Array of formats.
    * @param count     Size of 'limits' and 'formats' arrays.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   ChoiceFormat(const double* limits,
                const UnicodeString* formats,
                int32_t count );

   /**
    * Constructs a new ChoiceFormat with the given limits, closure flags and message strings.
    *
    * Copies the limits and formats instead of adopting them.
    *
    * @param limits Array of limit values
    * @param closures Array of booleans specifying whether each
    * element of 'limits' is open or closed.  If false, then the
    * corresponding limit number is a member of its range.
    * If true, then the limit number belongs to the previous range it.
    * @param formats Array of formats
    * @param count Size of 'limits', 'closures', and 'formats' arrays
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   ChoiceFormat(const double* limits,
                const UBool* closures,
                const UnicodeString* formats,
                int32_t count);

   /**
    * Copy constructor.
    *
    * @param that   ChoiceFormat object to be copied from
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   ChoiceFormat(const ChoiceFormat& that);

   /**
    * Assignment operator.
    *
    * @param that   ChoiceFormat object to be copied
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   const ChoiceFormat& operator=(const ChoiceFormat& that);

   /**
    * Destructor.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual ~ChoiceFormat();

   /**
    * Clones this Format object. The caller owns the
    * result and must delete it when done.
    *
    * @return a copy of this object
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual ChoiceFormat* clone() const override;

   /**
    * Returns true if the given Format objects are semantically equal.
    * Objects of different subclasses are considered unequal.
    *
    * @param other    ChoiceFormat object to be compared
    * @return         true if other is the same as this.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual bool operator==(const Format& other) const override;

   /**
    * Sets the pattern.
    * @param pattern   The pattern to be applied.
    * @param status    Output param set to success/failure code on
    *                  exit. If the pattern is invalid, this will be
    *                  set to a failure result.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual void applyPattern(const UnicodeString& pattern,
                             UErrorCode& status);

   /**
    * Sets the pattern.
    * @param pattern    The pattern to be applied.
    * @param parseError Struct to receive information on position
    *                   of error if an error is encountered
    * @param status     Output param set to success/failure code on
    *                   exit. If the pattern is invalid, this will be
    *                   set to a failure result.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual void applyPattern(const UnicodeString& pattern,
                            UParseError& parseError,
                            UErrorCode& status);
   /**
    * Gets the pattern.
    *
    * @param pattern    Output param which will receive the pattern
    *                   Previous contents are deleted.
    * @return    A reference to 'pattern'
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual UnicodeString& toPattern(UnicodeString &pattern) const;

   /**
    * Sets the choices to be used in formatting.
    * For details see the constructor with the same parameter list.
    *
    * @param limitsToCopy      Contains the top value that you want
    *                          parsed with that format,and should be in
    *                          ascending sorted order. When formatting X,
    *                          the choice will be the i, where limit[i]
    *                          &lt;= X &lt; limit[i+1].
    * @param formatsToCopy     The format strings you want to use for each limit.
    * @param count             The size of the above arrays.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual void setChoices(const double* limitsToCopy,
                           const UnicodeString* formatsToCopy,
                           int32_t count );

   /**
    * Sets the choices to be used in formatting.
    * For details see the constructor with the same parameter list.
    *
    * @param limits Array of limits
    * @param closures Array of limit booleans
    * @param formats Array of format string
    * @param count The size of the above arrays
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual void setChoices(const double* limits,
                           const UBool* closures,
                           const UnicodeString* formats,
                           int32_t count);

   /**
    * Returns nullptr and 0.
    * Before ICU 4.8, this used to return the choice limits array.
    *
    * @param count Will be set to 0.
    * @return nullptr
    * @deprecated ICU 4.8 Use the MessagePattern class to analyze a ChoiceFormat pattern.
    */
   virtual const double* getLimits(int32_t& count) const;

   /**
    * Returns nullptr and 0.
    * Before ICU 4.8, this used to return the limit booleans array.
    *
    * @param count Will be set to 0.
    * @return nullptr
    * @deprecated ICU 4.8 Use the MessagePattern class to analyze a ChoiceFormat pattern.
    */
   virtual const UBool* getClosures(int32_t& count) const;

   /**
    * Returns nullptr and 0.
    * Before ICU 4.8, this used to return the array of choice strings.
    *
    * @param count Will be set to 0.
    * @return nullptr
    * @deprecated ICU 4.8 Use the MessagePattern class to analyze a ChoiceFormat pattern.
    */
   virtual const UnicodeString* getFormats(int32_t& count) const;


   using NumberFormat::format;

   /**
    * Formats a double number using this object's choices.
    *
    * @param number    The value to be formatted.
    * @param appendTo  Output parameter to receive result.
    *                  Result is appended to existing contents.
    * @param pos       On input: an alignment field, if desired.
    *                  On output: the offsets of the alignment field.
    * @return          Reference to 'appendTo' parameter.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual UnicodeString& format(double number,
                                 UnicodeString& appendTo,
                                 FieldPosition& pos) const override;
   /**
    * Formats an int32_t number using this object's choices.
    *
    * @param number    The value to be formatted.
    * @param appendTo  Output parameter to receive result.
    *                  Result is appended to existing contents.
    * @param pos       On input: an alignment field, if desired.
    *                  On output: the offsets of the alignment field.
    * @return          Reference to 'appendTo' parameter.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual UnicodeString& format(int32_t number,
                                 UnicodeString& appendTo,
                                 FieldPosition& pos) const override;

   /**
    * Formats an int64_t number using this object's choices.
    *
    * @param number    The value to be formatted.
    * @param appendTo  Output parameter to receive result.
    *                  Result is appended to existing contents.
    * @param pos       On input: an alignment field, if desired.
    *                  On output: the offsets of the alignment field.
    * @return          Reference to 'appendTo' parameter.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual UnicodeString& format(int64_t number,
                                 UnicodeString& appendTo,
                                 FieldPosition& pos) const override;

   /**
    * Formats an array of objects using this object's choices.
    *
    * @param objs      The array of objects to be formatted.
    * @param cnt       The size of objs.
    * @param appendTo  Output parameter to receive result.
    *                  Result is appended to existing contents.
    * @param pos       On input: an alignment field, if desired.
    *                  On output: the offsets of the alignment field.
    * @param success   Output param set to success/failure code on
    *                  exit.
    * @return          Reference to 'appendTo' parameter.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual UnicodeString& format(const Formattable* objs,
                                 int32_t cnt,
                                 UnicodeString& appendTo,
                                 FieldPosition& pos,
                                 UErrorCode& success) const;

  using NumberFormat::parse;

  /**
   * Looks for the longest match of any message string on the input text and,
   * if there is a match, sets the result object to the corresponding range's number.
   *
   * If no string matches, then the parsePosition is unchanged.
   *
   * @param text           The text to be parsed.
   * @param result         Formattable to be set to the parse result.
   *                       If parse fails, return contents are undefined.
   * @param parsePosition  The position to start parsing at on input.
   *                       On output, moved to after the last successfully
   *                       parse character. On parse failure, does not change.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
   */
   virtual void parse(const UnicodeString& text,
                      Formattable& result,
                      ParsePosition& parsePosition) const override;

   /**
    * Returns a unique class ID POLYMORPHICALLY. Part of ICU's "poor man's RTTI".
    *
    * @return          The class ID for this object. All objects of a
    *                  given class have the same class ID.  Objects of
    *                  other classes have different class IDs.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   virtual UClassID getDynamicClassID() const override;

   /**
    * Returns the class ID for this class.  This is useful only for
    * comparing to a return value from getDynamicClassID().  For example:
    * <pre>
    * .       Base* polymorphic_pointer = createPolymorphicObject();
    * .       if (polymorphic_pointer->getDynamicClassID() ==
    * .           Derived::getStaticClassID()) ...
    * </pre>
    * @return          The class ID for all objects of this class.
    * @deprecated ICU 49 Use MessageFormat instead, with plural and select arguments.
    */
   static UClassID U_EXPORT2 getStaticClassID();

private:
   /**
    * Converts a double value to a string.
    * @param value the double number to be converted.
    * @param string the result string.
    * @return the converted string.
    */
   static UnicodeString& dtos(double value, UnicodeString& string);

   ChoiceFormat() = delete; // default constructor not implemented

   /**
    * Construct a new ChoiceFormat with the limits and the corresponding formats
    * based on the pattern.
    *
    * @param newPattern   Pattern used to construct object.
    * @param parseError   Struct to receive information on position
    *                     of error if an error is encountered.
    * @param status       Output param to receive success code.  If the
    *                     pattern cannot be parsed, set to failure code.
    */
   ChoiceFormat(const UnicodeString& newPattern,
                UParseError& parseError,
                UErrorCode& status);

   friend class MessageFormat;

   virtual void setChoices(const double* limits,
                           const UBool* closures,
                           const UnicodeString* formats,
                           int32_t count,
                           UErrorCode &errorCode);

   /**
    * Finds the ChoiceFormat sub-message for the given number.
    * @param pattern A MessagePattern.
    * @param partIndex the index of the first ChoiceFormat argument style part.
    * @param number a number to be mapped to one of the ChoiceFormat argument's intervals
    * @return the sub-message start part index.
    */
   static int32_t findSubMessage(const MessagePattern &pattern, int32_t partIndex, double number);

   static double parseArgument(
           const MessagePattern &pattern, int32_t partIndex,
           const UnicodeString &source, ParsePosition &pos);

   /**
    * Matches the pattern string from the end of the partIndex to
    * the beginning of the limitPartIndex,
    * including all syntax except SKIP_SYNTAX,
    * against the source string starting at sourceOffset.
    * If they match, returns the length of the source string match.
    * Otherwise returns -1.
    */
   static int32_t matchStringUntilLimitPart(
           const MessagePattern &pattern, int32_t partIndex, int32_t limitPartIndex,
           const UnicodeString &source, int32_t sourceOffset);

   /**
    * Some of the ChoiceFormat constructors do not have a UErrorCode parameter.
    * We need _some_ way to provide one for the MessagePattern constructor.
    * Alternatively, the MessagePattern could be a pointer field, but that is
    * not nice either.
    */
   UErrorCode constructorErrorCode;

   /**
    * The MessagePattern which contains the parsed structure of the pattern string.
    *
    * Starting with ICU 4.8, the MessagePattern contains a sequence of
    * numeric/selector/message parts corresponding to the parsed pattern.
    * For details see the MessagePattern class API docs.
    */
   MessagePattern msgPattern;

   /**
    * Docs & fields from before ICU 4.8, before MessagePattern was used.
    * Commented out, and left only for explanation of semantics.
    * --------
    * Each ChoiceFormat divides the range -Inf..+Inf into fCount
    * intervals.  The intervals are:
    *
    *         0: fChoiceLimits[0]..fChoiceLimits[1]
    *         1: fChoiceLimits[1]..fChoiceLimits[2]
    *        ...
    *  fCount-2: fChoiceLimits[fCount-2]..fChoiceLimits[fCount-1]
    *  fCount-1: fChoiceLimits[fCount-1]..+Inf
    *
    * Interval 0 is special; during formatting (mapping numbers to
    * strings), it also contains all numbers less than
    * fChoiceLimits[0], as well as NaN values.
    *
    * Interval i maps to and from string fChoiceFormats[i].  When
    * parsing (mapping strings to numbers), then intervals map to
    * their lower limit, that is, interval i maps to fChoiceLimit[i].
    *
    * The intervals may be closed, half open, or open.  This affects
    * formatting but does not affect parsing.  Interval i is affected
    * by fClosures[i] and fClosures[i+1].  If fClosures[i]
    * is false, then the value fChoiceLimits[i] is in interval i.
    * That is, intervals i and i are:
    *
    *  i-1:                 ... x < fChoiceLimits[i]
    *    i: fChoiceLimits[i] <= x ...
    *
    * If fClosures[i] is true, then the value fChoiceLimits[i] is
    * in interval i-1.  That is, intervals i-1 and i are:
    *
    *  i-1:                ... x <= fChoiceLimits[i]
    *    i: fChoiceLimits[i] < x ...
    *
    * Because of the nature of interval 0, fClosures[0] has no
    * effect.
    */
   // double*         fChoiceLimits;
   // UBool*          fClosures;
   // UnicodeString*  fChoiceFormats;
   // int32_t         fCount;
};


U_NAMESPACE_END

#endif  // U_HIDE_DEPRECATED_API
#endif /* #if !UCONFIG_NO_FORMATTING */

#endif /* U_SHOW_CPLUSPLUS_API */

#endif // CHOICFMT_H
//eof