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1 /*
2 ********************************************************************************
3 *   Copyright (C) 1997-2005, International Business Machines
4 *   Corporation and others.  All Rights Reserved.
5 ********************************************************************************
6 *
7 * File CHOICFMT.H
8 *
9 * Modification History:
10 *
11 *   Date        Name        Description
12 *   02/19/97    aliu        Converted from java.
13 *   03/20/97    helena      Finished first cut of implementation and got rid
14 *                           of nextDouble/previousDouble and replaced with
15 *                           boolean array.
16 *   4/10/97     aliu        Clean up.  Modified to work on AIX.
17 *   8/6/97      nos         Removed overloaded constructor, member var 'buffer'.
18 *   07/22/98    stephen     Removed operator!= (implemented in Format)
19 ********************************************************************************
20 */
21 
22 #ifndef CHOICFMT_H
23 #define CHOICFMT_H
24 
25 #include "unicode/utypes.h"
26 
27 /**
28  * \file
29  * \brief C++ API: Choice Format.
30  */
31 
32 #if !UCONFIG_NO_FORMATTING
33 
34 #include "unicode/unistr.h"
35 #include "unicode/numfmt.h"
36 #include "unicode/fieldpos.h"
37 #include "unicode/format.h"
38 
39 U_NAMESPACE_BEGIN
40 
41 class MessageFormat;
42 
43 /**
44  * ChoiceFormat converts between ranges of numeric values
45  * and string names for those ranges. A <code>ChoiceFormat</code> splits
46  * the real number line <code>-Inf</code> to <code>+Inf</code> into two
47  * or more contiguous ranges. Each range is mapped to a
48  * string. <code>ChoiceFormat</code> is generally used in a
49  * <code>MessageFormat</code> for displaying grammatically correct
50  * plurals such as &quot;There are 2 files.&quot;</p>
51  *
52  * <p>There are two methods of defining a <code>ChoiceFormat</code>; both
53  * are equivalent.  The first is by using a string pattern. This is the
54  * preferred method in most cases.  The second method is through direct
55  * specification of the arrays that make up the
56  * <code>ChoiceFormat</code>.</p>
57  *
58  * <p><strong>Patterns</strong></p>
59  *
60  * <p>In most cases, the preferred way to define a
61  * <code>ChoiceFormat</code> is with a pattern. Here is an example of a
62  * <code>ChoiceFormat</code> pattern:</p>
63  *
64  * \htmlonly<pre>    0&#x2264;are no files|1&#x2264;is one file|1&lt;are many files</pre>\endhtmlonly
65  *
66  * <p>or equivalently,</p>
67  *
68  * \htmlonly<pre>    0#are no files|1#is one file|1&lt;are many files</pre>\endhtmlonly
69  *
70  * <p>The pattern consists of a number or <em>range specifiers</em>
71  * separated by vertical bars '|' (U+007C). There is no
72  * vertical bar after the last range.  Each range specifier is of the
73  * form:</p>
74  *
75  * \htmlonly<blockquote><em>Number Separator String</em></blockquote>\endhtmlonly
76  *
77  * <p><em>Number</em> is a floating point number that can be parsed by a
78  * default <code>NumberFormat</code> for the US locale. It gives the
79  * lower limit of this range. The lower limit is either inclusive or
80  * exclusive, depending on the <em>separator</em>. The upper limit is
81  * given by the lower limit of the next range.  The Unicode infinity
82  * sign \htmlonly&#x221E \endhtmlonly (U+221E) is recognized for positive infinity. It may be preceded by
83  * '-' (U+002D) to indicate negative infinity.</p>
84  *
85  * <p><em>String</em> is the format string for this range, with special
86  * characters enclosed in single quotes (<code>'The #
87  * sign'</code>). Single quotes themselves are indicated by two single
88  * quotes in a row (<code>'o''clock'</code>).</p>
89  *
90  * <p><em>Separator</em> is one of the following single characters:
91  *
92  * <ul>
93  *   <li>\htmlonly'&#x2264;' \endhtmlonly (U+2264) or '#' (U+0023)
94  *   indicates that the lower limit given by <em>Number</em> is
95  *   inclusive.  (The two characters are equivalent to ChoiceFormat.)
96  *   This means that the limit value <em>Number</em> belongs to this
97  *   range.  Another way of saying this is that the corresponding
98  *   closure is <code>FALSE</code>.</li>
99  *
100  *   <li>'<' (U+003C) indicates that the lower limit given by
101  *   <em>Number</em> is exclusive.  This means that the value
102  *   <em>Number</em> belongs to the prior range.</li> Another way of
103  *   saying this is that the corresponding closure is
104  *   <code>TRUE</code>.
105  * </ul>
106  *
107  * <p>See below for more information about closures.</p>
108  *
109  * <p><strong>Arrays</strong></p>
110  *
111  * <p>A <code>ChoiceFormat</code> defining <code>n</code> intervals
112  * (<code>n</code> &gt;= 2) is specified by three arrays of
113  * <code>n</code> items:
114  *
115  * <ul>
116  *   <li><code>double limits[]</code> gives the start of each
117  *     interval. This must be a non-decreasing list of values, none of
118  *     which may be <code>NaN</code>.</li>
119  *   <li><code>UBool closures[]</code> determines whether each limit
120  *     value is contained in the interval below it or in the interval
121  *     above it. If <code>closures[i]</code> is <code>FALSE</code>, then
122  *     <code>limits[i]</code> is a member of interval
123  *     <code>i</code>. Otherwise it is a member of interval
124  *     <code>i+1</code>. If no closures array is specified, this is
125  *     equivalent to having all closures be <code>FALSE</code>. Closures
126  *     allow one to specify half-open, open, or closed intervals.</li>
127  *   <li><code>UnicodeString formats[]</code> gives the string label
128  *     associated with each interval.</li>
129  * </ul>
130  *
131  * <p><strong>Formatting and Parsing</strong></p>
132  *
133  * <p>During formatting, a number is converted to a
134  * string. <code>ChoiceFormat</code> accomplishes this by mapping the
135  * number to an interval using the following rule. Given a number
136  * <code>X</code> and and index value <code>j</code> in the range
137  * <code>0..n-1</code>, where <code>n</code> is the number of ranges:</p>
138  *
139  * \htmlonly<blockquote>\endhtmlonly<code>X</code> matches <code>j</code> if and only if
140  * <code>limit[j] &lt;= X &lt; limit[j+1]</code>
141  * \htmlonly</blockquote>\endhtmlonly
142  *
143  * <p>(This assumes that all closures are <code>FALSE</code>.  If some
144  * closures are <code>TRUE</code> then the relations must be changed to
145  * <code>&lt;=</code> or <code>&lt;</code> as appropriate.) If there is
146  * no match, then either the first or last index is used, depending on
147  * whether the number is too low or too high. Once a number is mapped to
148  * an interval <code>j</code>, the string <code>formats[j]</code> is
149  * output.</p>
150  *
151  * <p>During parsing, a string is converted to a
152  * number. <code>ChoiceFormat</code> finds the element
153  * <code>formats[j]</code> equal to the string, and returns
154  * <code>limits[j]</code> as the parsed value.</p>
155  *
156  * <p><strong>Notes</strong></p>
157  *
158  * <p>The first limit value does not define a range boundary. For
159  * example, in the pattern \htmlonly&quot;<code>1.0#a|2.0#b</code>&quot;\endhtmlonly, the
160  * intervals are [-Inf, 2.0) and [2.0, +Inf].  It appears that the first
161  * interval should be [1.0, 2.0).  However, since all values that are too
162  * small are mapped to range zero, the first interval is effectively
163  * [-Inf, 2.0).  However, the first limit value <em>is</em> used during
164  * formatting. In this example, <code>parse(&quot;a&quot;)</code> returns
165  * 1.0.</p>
166  *
167  * <p>There are no gaps between intervals and the entire number line is
168  * covered.  A <code>ChoiceFormat</code> maps <em>all</em> possible
169  * double values to a finite set of intervals.</p>
170  *
171  * <p>The non-number <code>NaN</code> is mapped to interval zero during
172  * formatting.</p>
173  *
174  * <p><strong>Examples</strong></p>
175  *
176  * <p>Here is an example of two arrays that map the number
177  * <code>1..7</code> to the English day of the week abbreviations
178  * <code>Sun..Sat</code>. No closures array is given; this is the same as
179  * specifying all closures to be <code>FALSE</code>.</p>
180  *
181  * <pre>    {1,2,3,4,5,6,7},
182  *     {&quot;Sun&quot;,&quot;Mon&quot;,&quot;Tue&quot;,&quot;Wed&quot;,&quot;Thur&quot;,&quot;Fri&quot;,&quot;Sat&quot;}</pre>
183  *
184  * <p>Here is an example that maps the ranges [-Inf, 1), [1, 1], and (1,
185  * +Inf] to three strings. That is, the number line is split into three
186  * ranges: x &lt; 1.0, x = 1.0, and x &gt; 1.0.</p>
187  *
188  * <pre>    {0, 1, 1},
189  *     {FALSE, FALSE, TRUE},
190  *     {&quot;no files&quot;, &quot;one file&quot;, &quot;many files&quot;}</pre>
191  *
192  * <p>Here is a simple example that shows formatting and parsing: </p>
193  *
194  * \code
195  *   #include <unicode/choicfmt.h>
196  *   #include <unicode/unistr.h>
197  *   #include <iostream.h>
198  *
199  *   int main(int argc, char *argv[]) {
200  *       double limits[] = {1,2,3,4,5,6,7};
201  *       UnicodeString monthNames[] = {
202  *           "Sun","Mon","Tue","Wed","Thu","Fri","Sat"};
203  *       ChoiceFormat fmt(limits, monthNames, 7);
204  *       UnicodeString str;
205  *       char buf[256];
206  *       for (double x = 1.0; x <= 8.0; x += 1.0) {
207  *           fmt.format(x, str);
208  *           str.extract(0, str.length(), buf, 256, "");
209  *           str.truncate(0);
210  *           cout << x << " -> "
211  *                << buf << endl;
212  *       }
213  *       cout << endl;
214  *       return 0;
215  *   }
216  * \endcode
217  *
218  * <p>Here is a more complex example using a <code>ChoiceFormat</code>
219  * constructed from a pattern together with a
220  * <code>MessageFormat</code>.</p>
221  *
222  * \code
223  *   #include <unicode/choicfmt.h>
224  *   #include <unicode/msgfmt.h>
225  *   #include <unicode/unistr.h>
226  *   #include <iostream.h>
227  *
228  *   int main(int argc, char *argv[]) {
229  *       UErrorCode status = U_ZERO_ERROR;
230  *       double filelimits[] = {0,1,2};
231  *       UnicodeString filepart[] =
232  *           {"are no files","is one file","are {0} files"};
233  *       ChoiceFormat* fileform = new ChoiceFormat(filelimits, filepart, 3 );
234  *       Format* testFormats[] =
235  *           {fileform, NULL, NumberFormat::createInstance(status)};
236  *       MessageFormat pattform("There {0} on {1}", status );
237  *       pattform.adoptFormats(testFormats, 3);
238  *       Formattable testArgs[] = {0L, "Disk A"};
239  *       FieldPosition fp(0);
240  *       UnicodeString str;
241  *       char buf[256];
242  *       for (int32_t i = 0; i < 4; ++i) {
243  *           Formattable fInt(i);
244  *           testArgs[0] = fInt;
245  *           pattform.format(testArgs, 2, str, fp, status );
246  *           str.extract(0, str.length(), buf, "");
247  *           str.truncate(0);
248  *           cout << "Output for i=" << i << " : " << buf << endl;
249  *       }
250  *       cout << endl;
251  *       return 0;
252  *   }
253  * \endcode
254  *
255  * <p><em>User subclasses are not supported.</em> While clients may write
256  * subclasses, such code will not necessarily work and will not be
257  * guaranteed to work stably from release to release.
258  */
259 class U_I18N_API ChoiceFormat: public NumberFormat {
260 public:
261     /**
262      * Construct a new ChoiceFormat with the limits and the corresponding formats
263      * based on the pattern.
264      *
265      * @param pattern   Pattern used to construct object.
266      * @param status    Output param to receive success code.  If the
267      *                  pattern cannot be parsed, set to failure code.
268      * @stable ICU 2.0
269      */
270     ChoiceFormat(const UnicodeString& pattern,
271                  UErrorCode& status);
272 
273 
274     /**
275      * Construct a new ChoiceFormat with the given limits and formats.  Copy
276      * the limits and formats instead of adopting them.
277      *
278      * @param limits    Array of limit values.
279      * @param formats   Array of formats.
280      * @param count     Size of 'limits' and 'formats' arrays.
281      * @stable ICU 2.0
282      */
283 
284     ChoiceFormat(const double* limits,
285                  const UnicodeString* formats,
286                  int32_t count );
287 
288     /**
289      * Construct a new ChoiceFormat with the given limits and formats.
290      * Copy the limits and formats (instead of adopting them).  By
291      * default, each limit in the array specifies the inclusive lower
292      * bound of its range, and the exclusive upper bound of the previous
293      * range.  However, if the isLimitOpen element corresponding to a
294      * limit is TRUE, then the limit is the exclusive lower bound of its
295      * range, and the inclusive upper bound of the previous range.
296      * @param limits Array of limit values
297      * @param closures Array of booleans specifying whether each
298      * element of 'limits' is open or closed.  If FALSE, then the
299      * corresponding limit is a member of the range above it.  If TRUE,
300      * then the limit belongs to the range below it.
301      * @param formats Array of formats
302      * @param count Size of 'limits', 'closures', and 'formats' arrays
303      * @stable ICU 2.4
304      */
305     ChoiceFormat(const double* limits,
306                  const UBool* closures,
307                  const UnicodeString* formats,
308                  int32_t count);
309 
310     /**
311      * Copy constructor.
312      *
313      * @param that   ChoiceFormat object to be copied from
314      * @stable ICU 2.0
315      */
316     ChoiceFormat(const ChoiceFormat& that);
317 
318     /**
319      * Assignment operator.
320      *
321      * @param that   ChoiceFormat object to be copied
322      * @stable ICU 2.0
323      */
324     const ChoiceFormat& operator=(const ChoiceFormat& that);
325 
326     /**
327      * Destructor.
328      * @stable ICU 2.0
329      */
330     virtual ~ChoiceFormat();
331 
332     /**
333      * Clone this Format object polymorphically. The caller owns the
334      * result and should delete it when done.
335      *
336      * @return a copy of this object
337      * @stable ICU 2.0
338      */
339     virtual Format* clone(void) const;
340 
341     /**
342      * Return true if the given Format objects are semantically equal.
343      * Objects of different subclasses are considered unequal.
344      *
345      * @param other    ChoiceFormat object to be compared
346      * @return         true if other is the same as this.
347      * @stable ICU 2.0
348      */
349     virtual UBool operator==(const Format& other) const;
350 
351     /**
352      * Sets the pattern.
353      * @param pattern   The pattern to be applied.
354      * @param status    Output param set to success/failure code on
355      *                  exit. If the pattern is invalid, this will be
356      *                  set to a failure result.
357      * @stable ICU 2.0
358      */
359     virtual void applyPattern(const UnicodeString& pattern,
360                               UErrorCode& status);
361 
362     /**
363      * Sets the pattern.
364      * @param pattern    The pattern to be applied.
365      * @param parseError Struct to recieve information on position
366      *                   of error if an error is encountered
367      * @param status     Output param set to success/failure code on
368      *                   exit. If the pattern is invalid, this will be
369      *                   set to a failure result.
370      * @stable ICU 2.0
371      */
372     virtual void applyPattern(const UnicodeString& pattern,
373                              UParseError& parseError,
374                              UErrorCode& status);
375     /**
376      * Gets the pattern.
377      *
378      * @param pattern    Output param which will recieve the pattern
379      *                   Previous contents are deleted.
380      * @return    A reference to 'pattern'
381      * @stable ICU 2.0
382      */
383     virtual UnicodeString& toPattern(UnicodeString &pattern) const;
384 
385 #ifdef U_USE_CHOICE_FORMAT_DEPRECATES
386     /**
387      * Set the choices to be used in formatting.  The arrays are adopted and
388      * should not be deleted by the caller.
389      *
390      * @param limitsToAdopt     Contains the top value that you want
391      *                          parsed with that format,and should be in
392      *                          ascending sorted order. When formatting X,
393      *                          the choice will be the i, where limit[i]
394      *                          &lt;= X &lt; limit[i+1].
395      * @param formatsToAdopt    The format strings you want to use for each limit.
396      * @param count             The size of the above arrays.
397      * @obsolete ICU 2.6. Use setChoices instead since this API will be removed in that release.
398      */
399     virtual void adoptChoices(double* limitsToAdopt,
400                               UnicodeString* formatsToAdopt,
401                               int32_t count );
402 
403     /**
404      * Set the choices to be used in formatting.  The arrays are adopted
405      * and should not be deleted by the caller.  See class description
406      * for documenatation of the limits, closures, and formats arrays.
407      * @param limitsToAdopt Array of limits to adopt
408      * @param closuresToAdopt Array of limit booleans to adopt
409      * @param formatsToAdopt Array of format string to adopt
410      * @param count The size of the above arrays
411      * @obsolete ICU 2.6. Use setChoices instead since this API will be removed in that release.
412      */
413     virtual void adoptChoices(double* limitsToAdopt,
414                               UBool* closuresToAdopt,
415                               UnicodeString* formatsToAdopt,
416                               int32_t count);
417 #endif
418 
419     /**
420      * Set the choices to be used in formatting.
421      *
422      * @param limitsToCopy      Contains the top value that you want
423      *                          parsed with that format,and should be in
424      *                          ascending sorted order. When formatting X,
425      *                          the choice will be the i, where limit[i]
426      *                          &lt;= X &lt; limit[i+1].
427      * @param formatsToCopy     The format strings you want to use for each limit.
428      * @param count             The size of the above arrays.
429      * @stable ICU 2.0
430      */
431     virtual void setChoices(const double* limitsToCopy,
432                             const UnicodeString* formatsToCopy,
433                             int32_t count );
434 
435     /**
436      * Set the choices to be used in formatting.  See class description
437      * for documenatation of the limits, closures, and formats arrays.
438      * @param limits Array of limits
439      * @param closures Array of limit booleans
440      * @param formats Array of format string
441      * @param count The size of the above arrays
442      * @stable ICU 2.4
443      */
444     virtual void setChoices(const double* limits,
445                             const UBool* closures,
446                             const UnicodeString* formats,
447                             int32_t count);
448 
449     /**
450      * Get the limits passed in the constructor.
451      *
452      * @param count    The size of the limits arrays
453      * @return the limits.
454      * @stable ICU 2.0
455      */
456     virtual const double* getLimits(int32_t& count) const;
457 
458     /**
459      * Get the limit booleans passed in the constructor.  The caller
460      * must not delete the result.
461      *
462      * @param count   The size of the arrays
463      * @return the closures
464      * @stable ICU 2.4
465      */
466     virtual const UBool* getClosures(int32_t& count) const;
467 
468     /**
469      * Get the formats passed in the constructor.
470      *
471      * @param count   The size of the arrays
472      * @return the formats.
473      * @stable ICU 2.0
474      */
475     virtual const UnicodeString* getFormats(int32_t& count) const;
476 
477     /**
478      * Format a double or long number using this object's choices.
479      *
480      * @param number    The value to be formatted.
481      * @param appendTo  Output parameter to receive result.
482      *                  Result is appended to existing contents.
483      * @param pos       On input: an alignment field, if desired.
484      *                  On output: the offsets of the alignment field.
485      * @return          Reference to 'appendTo' parameter.
486      * @stable ICU 2.0
487      */
488     virtual UnicodeString& format(double number,
489                                   UnicodeString& appendTo,
490                                   FieldPosition& pos) const;
491     /**
492      * Format a int_32t number using this object's choices.
493      *
494      * @param number    The value to be formatted.
495      * @param appendTo  Output parameter to receive result.
496      *                  Result is appended to existing contents.
497      * @param pos       On input: an alignment field, if desired.
498      *                  On output: the offsets of the alignment field.
499      * @return          Reference to 'appendTo' parameter.
500      * @stable ICU 2.0
501      */
502     virtual UnicodeString& format(int32_t number,
503                                   UnicodeString& appendTo,
504                                   FieldPosition& pos) const;
505 
506     /**
507      * Format an int64_t number using this object's choices.
508      *
509      * @param number    The value to be formatted.
510      * @param appendTo  Output parameter to receive result.
511      *                  Result is appended to existing contents.
512      * @param pos       On input: an alignment field, if desired.
513      *                  On output: the offsets of the alignment field.
514      * @return          Reference to 'appendTo' parameter.
515      * @stable ICU 2.8
516      */
517     virtual UnicodeString& format(int64_t number,
518                                   UnicodeString& appendTo,
519                                   FieldPosition& pos) const;
520 
521     /**
522      * Format an array of objects using this object's choices.
523      *
524      * @param objs      The array of objects to be formatted.
525      * @param cnt       The size of objs.
526      * @param appendTo  Output parameter to receive result.
527      *                  Result is appended to existing contents.
528      * @param pos       On input: an alignment field, if desired.
529      *                  On output: the offsets of the alignment field.
530      * @param success   Output param set to success/failure code on
531      *                  exit.
532      * @return          Reference to 'appendTo' parameter.
533      * @stable ICU 2.0
534      */
535     virtual UnicodeString& format(const Formattable* objs,
536                                   int32_t cnt,
537                                   UnicodeString& appendTo,
538                                   FieldPosition& pos,
539                                   UErrorCode& success) const;
540     /**
541      * Format an object using this object's choices.
542      *
543      *
544      * @param obj       The object to be formatted.
545      * @param appendTo  Output parameter to receive result.
546      *                  Result is appended to existing contents.
547      * @param pos       On input: an alignment field, if desired.
548      *                  On output: the offsets of the alignment field.
549      * @param status    Output param set to success/failure code on
550      *                  exit.
551      * @return          Reference to 'appendTo' parameter.
552      * @stable ICU 2.0
553      */
554     virtual UnicodeString& format(const Formattable& obj,
555                                   UnicodeString& appendTo,
556                                   FieldPosition& pos,
557                                   UErrorCode& status) const;
558 
559     /**
560      * Redeclared NumberFormat method.
561      *
562      * @param obj       The object to be formatted.
563      * @param appendTo  Output parameter to receive result.
564      *                  Result is appended to existing contents.
565      * @param status    Output param set to success/failure code on
566      *                  exit.
567      * @return          Reference to 'appendTo' parameter.
568      * @stable ICU 2.0
569      */
570     UnicodeString& format(const Formattable& obj,
571                           UnicodeString& appendTo,
572                           UErrorCode& status) const;
573 
574     /**
575      * Redeclared NumberFormat method.
576      * Format a double number. These methods call the NumberFormat
577      * pure virtual format() methods with the default FieldPosition.
578      *
579      * @param number    The value to be formatted.
580      * @param appendTo  Output parameter to receive result.
581      *                  Result is appended to existing contents.
582      * @return          Reference to 'appendTo' parameter.
583      * @stable ICU 2.0
584      */
585     UnicodeString& format(  double number,
586                             UnicodeString& appendTo) const;
587 
588     /**
589      * Redeclared NumberFormat method.
590      * Format a long number. These methods call the NumberFormat
591      * pure virtual format() methods with the default FieldPosition.
592      *
593      * @param number    The value to be formatted.
594      * @param appendTo  Output parameter to receive result.
595      *                  Result is appended to existing contents.
596      * @return          Reference to 'appendTo' parameter.
597      * @stable ICU 2.0
598      */
599     UnicodeString& format(  int32_t number,
600                             UnicodeString& appendTo) const;
601 
602    /**
603     * Return a long if possible (e.g. within range LONG_MAX,
604     * LONG_MAX], and with no decimals), otherwise a double.  If
605     * IntegerOnly is set, will stop at a decimal point (or equivalent;
606     * e.g. for rational numbers "1 2/3", will stop after the 1).
607     * <P>
608     * If no object can be parsed, parsePosition is unchanged, and NULL is
609     * returned.
610     *
611     * @param text           The text to be parsed.
612     * @param result         Formattable to be set to the parse result.
613     *                       If parse fails, return contents are undefined.
614     * @param parsePosition  The position to start parsing at on input.
615     *                       On output, moved to after the last successfully
616     *                       parse character. On parse failure, does not change.
617     * @see                  NumberFormat::isParseIntegerOnly
618     * @stable ICU 2.0
619     */
620     virtual void parse(const UnicodeString& text,
621                        Formattable& result,
622                        ParsePosition& parsePosition) const;
623 
624     /**
625     * Return a long if possible (e.g. within range LONG_MAX,
626     * LONG_MAX], and with no decimals), otherwise a double.  If
627     * IntegerOnly is set, will stop at a decimal point (or equivalent;
628     * e.g. for rational numbers "1 2/3", will stop after the 1).
629     * <P>
630     * If no object can be parsed, parsePosition is unchanged, and NULL is
631     * returned.
632     *
633     * @param text           The text to be parsed.
634     * @param result         Formattable to be set to the parse result.
635     *                       If parse fails, return contents are undefined.
636     * @param status         Output param with the formatted string.
637     * @see                  NumberFormat::isParseIntegerOnly
638     * @stable ICU 2.0
639     */
640     virtual void parse(const UnicodeString& text,
641                        Formattable& result,
642                        UErrorCode& status) const;
643 
644 
645 public:
646     /**
647      * Returns a unique class ID POLYMORPHICALLY.  Pure virtual override.
648      * This method is to implement a simple version of RTTI, since not all
649      * C++ compilers support genuine RTTI.  Polymorphic operator==() and
650      * clone() methods call this method.
651      *
652      * @return          The class ID for this object. All objects of a
653      *                  given class have the same class ID.  Objects of
654      *                  other classes have different class IDs.
655      * @stable ICU 2.0
656      */
657     virtual UClassID getDynamicClassID(void) const;
658 
659     /**
660      * Return the class ID for this class.  This is useful only for
661      * comparing to a return value from getDynamicClassID().  For example:
662      * <pre>
663      * .       Base* polymorphic_pointer = createPolymorphicObject();
664      * .       if (polymorphic_pointer->getDynamicClassID() ==
665      * .           Derived::getStaticClassID()) ...
666      * </pre>
667      * @return          The class ID for all objects of this class.
668      * @stable ICU 2.0
669      */
670     static UClassID U_EXPORT2 getStaticClassID(void);
671 
672 private:
673     // static cache management (thread-safe)
674   //  static NumberFormat* getNumberFormat(UErrorCode &status); // call this function to 'check out' a numberformat from the cache.
675   //  static void          releaseNumberFormat(NumberFormat *adopt); // call this function to 'return' the number format to the cache.
676 
677     /**
678      * Converts a string to a double value using a default NumberFormat object
679      * which is static (shared by all ChoiceFormat instances).
680      * @param string the string to be converted with.
681      * @return the converted double number.
682      */
683     static double stod(const UnicodeString& string);
684 
685     /**
686      * Converts a double value to a string using a default NumberFormat object
687      * which is static (shared by all ChoiceFormat instances).
688      * @param value the double number to be converted with.
689      * @param string the result string.
690      * @return the converted string.
691      */
692     static UnicodeString& dtos(double value, UnicodeString& string);
693 
694     ChoiceFormat(); // default constructor not implemented
695 
696     /**
697      * Construct a new ChoiceFormat with the limits and the corresponding formats
698      * based on the pattern.
699      *
700      * @param newPattern   Pattern used to construct object.
701      * @param parseError   Struct to recieve information on position
702      *                     of error if an error is encountered.
703      * @param status       Output param to receive success code.  If the
704      *                     pattern cannot be parsed, set to failure code.
705      * @stable ICU 2.0
706      */
707     ChoiceFormat(const UnicodeString& newPattern,
708                  UParseError& parseError,
709                  UErrorCode& status);
710 
711     friend class MessageFormat;
712     /**
713      * Each ChoiceFormat divides the range -Inf..+Inf into fCount
714      * intervals.  The intervals are:
715      *
716      *         0: fChoiceLimits[0]..fChoiceLimits[1]
717      *         1: fChoiceLimits[1]..fChoiceLimits[2]
718      *        ...
719      *  fCount-2: fChoiceLimits[fCount-2]..fChoiceLimits[fCount-1]
720      *  fCount-1: fChoiceLimits[fCount-1]..+Inf
721      *
722      * Interval 0 is special; during formatting (mapping numbers to
723      * strings), it also contains all numbers less than
724      * fChoiceLimits[0], as well as NaN values.
725      *
726      * Interval i maps to and from string fChoiceFormats[i].  When
727      * parsing (mapping strings to numbers), then intervals map to
728      * their lower limit, that is, interval i maps to fChoiceLimit[i].
729      *
730      * The intervals may be closed, half open, or open.  This affects
731      * formatting but does not affect parsing.  Interval i is affected
732      * by fClosures[i] and fClosures[i+1].  If fClosures[i]
733      * is FALSE, then the value fChoiceLimits[i] is in interval i.
734      * That is, intervals i and i are:
735      *
736      *  i-1:                 ... x < fChoiceLimits[i]
737      *    i: fChoiceLimits[i] <= x ...
738      *
739      * If fClosures[i] is TRUE, then the value fChoiceLimits[i] is
740      * in interval i-1.  That is, intervals i-1 and i are:
741      *
742      *  i-1:                ... x <= fChoiceLimits[i]
743      *    i: fChoiceLimits[i] < x ...
744      *
745      * Because of the nature of interval 0, fClosures[0] has no
746      * effect.
747 
748      */
749     double*         fChoiceLimits;
750     UBool*          fClosures;
751     UnicodeString*  fChoiceFormats;
752     int32_t         fCount;
753 };
754 
755 inline UnicodeString&
format(const Formattable & obj,UnicodeString & appendTo,UErrorCode & status)756 ChoiceFormat::format(const Formattable& obj,
757                      UnicodeString& appendTo,
758                      UErrorCode& status) const {
759     // Don't use Format:: - use immediate base class only,
760     // in case immediate base modifies behavior later.
761     return NumberFormat::format(obj, appendTo, status);
762 }
763 
764 inline UnicodeString&
format(double number,UnicodeString & appendTo)765 ChoiceFormat::format(double number,
766                      UnicodeString& appendTo) const {
767     return NumberFormat::format(number, appendTo);
768 }
769 
770 inline UnicodeString&
format(int32_t number,UnicodeString & appendTo)771 ChoiceFormat::format(int32_t number,
772                      UnicodeString& appendTo) const {
773     return NumberFormat::format(number, appendTo);
774 }
775 U_NAMESPACE_END
776 
777 #endif /* #if !UCONFIG_NO_FORMATTING */
778 
779 #endif // _CHOICFMT
780 //eof
781