1/*
2*******************************************************************************
3* Copyright (C) 1997-2015, International Business Machines Corporation and others.
4* All Rights Reserved.
5*******************************************************************************
6*/
7
8#ifndef RBNF_H
9#define RBNF_H
10
11#include "unicode/utypes.h"
12
13/**
14 * \file
15 * \brief C++ API: Rule Based Number Format
16 */
17
18/**
19 * \def U_HAVE_RBNF
20 * This will be 0 if RBNF support is not included in ICU
21 * and 1 if it is.
22 *
23 * @stable ICU 2.4
24 */
25#if UCONFIG_NO_FORMATTING
26#define U_HAVE_RBNF 0
27#else
28#define U_HAVE_RBNF 1
29
30#include "unicode/dcfmtsym.h"
31#include "unicode/fmtable.h"
32#include "unicode/locid.h"
33#include "unicode/numfmt.h"
34#include "unicode/unistr.h"
35#include "unicode/strenum.h"
36#include "unicode/brkiter.h"
37#include "unicode/upluralrules.h"
38
39U_NAMESPACE_BEGIN
40
41class NFRuleSet;
42class LocalizationInfo;
43class PluralFormat;
44class RuleBasedCollator;
45
46/**
47 * Tags for the predefined rulesets.
48 *
49 * @stable ICU 2.2
50 */
51enum URBNFRuleSetTag {
52    URBNF_SPELLOUT,
53    URBNF_ORDINAL,
54    URBNF_DURATION,
55    URBNF_NUMBERING_SYSTEM,
56    URBNF_COUNT
57};
58
59/**
60 * The RuleBasedNumberFormat class formats numbers according to a set of rules. This number formatter is
61 * typically used for spelling out numeric values in words (e.g., 25,3476 as
62 * "twenty-five thousand three hundred seventy-six" or "vingt-cinq mille trois
63 * cents soixante-seize" or
64 * "fünfundzwanzigtausenddreihundertsechsundsiebzig"), but can also be used for
65 * other complicated formatting tasks, such as formatting a number of seconds as hours,
66 * minutes and seconds (e.g., 3,730 as "1:02:10").
67 *
68 * <p>The resources contain three predefined formatters for each locale: spellout, which
69 * spells out a value in words (123 is &quot;one hundred twenty-three&quot;); ordinal, which
70 * appends an ordinal suffix to the end of a numeral (123 is &quot;123rd&quot;); and
71 * duration, which shows a duration in seconds as hours, minutes, and seconds (123 is
72 * &quot;2:03&quot;).&nbsp; The client can also define more specialized <tt>RuleBasedNumberFormat</tt>s
73 * by supplying programmer-defined rule sets.</p>
74 *
75 * <p>The behavior of a <tt>RuleBasedNumberFormat</tt> is specified by a textual description
76 * that is either passed to the constructor as a <tt>String</tt> or loaded from a resource
77 * bundle. In its simplest form, the description consists of a semicolon-delimited list of <em>rules.</em>
78 * Each rule has a string of output text and a value or range of values it is applicable to.
79 * In a typical spellout rule set, the first twenty rules are the words for the numbers from
80 * 0 to 19:</p>
81 *
82 * <pre>zero; one; two; three; four; five; six; seven; eight; nine;
83 * ten; eleven; twelve; thirteen; fourteen; fifteen; sixteen; seventeen; eighteen; nineteen;</pre>
84 *
85 * <p>For larger numbers, we can use the preceding set of rules to format the ones place, and
86 * we only have to supply the words for the multiples of 10:</p>
87 *
88 * <pre> 20: twenty[-&gt;&gt;];
89 * 30: thirty[-&gt;&gt;];
90 * 40: forty[-&gt;&gt;];
91 * 50: fifty[-&gt;&gt;];
92 * 60: sixty[-&gt;&gt;];
93 * 70: seventy[-&gt;&gt;];
94 * 80: eighty[-&gt;&gt;];
95 * 90: ninety[-&gt;&gt;];</pre>
96 *
97 * <p>In these rules, the <em>base value</em> is spelled out explicitly and set off from the
98 * rule's output text with a colon. The rules are in a sorted list, and a rule is applicable
99 * to all numbers from its own base value to one less than the next rule's base value. The
100 * &quot;&gt;&gt;&quot; token is called a <em>substitution</em> and tells the fomatter to
101 * isolate the number's ones digit, format it using this same set of rules, and place the
102 * result at the position of the &quot;&gt;&gt;&quot; token. Text in brackets is omitted if
103 * the number being formatted is an even multiple of 10 (the hyphen is a literal hyphen; 24
104 * is &quot;twenty-four,&quot; not &quot;twenty four&quot;).</p>
105 *
106 * <p>For even larger numbers, we can actually look up several parts of the number in the
107 * list:</p>
108 *
109 * <pre>100: &lt;&lt; hundred[ &gt;&gt;];</pre>
110 *
111 * <p>The &quot;&lt;&lt;&quot; represents a new kind of substitution. The &lt;&lt; isolates
112 * the hundreds digit (and any digits to its left), formats it using this same rule set, and
113 * places the result where the &quot;&lt;&lt;&quot; was. Notice also that the meaning of
114 * &gt;&gt; has changed: it now refers to both the tens and the ones digits. The meaning of
115 * both substitutions depends on the rule's base value. The base value determines the rule's <em>divisor,</em>
116 * which is the highest power of 10 that is less than or equal to the base value (the user
117 * can change this). To fill in the substitutions, the formatter divides the number being
118 * formatted by the divisor. The integral quotient is used to fill in the &lt;&lt;
119 * substitution, and the remainder is used to fill in the &gt;&gt; substitution. The meaning
120 * of the brackets changes similarly: text in brackets is omitted if the value being
121 * formatted is an even multiple of the rule's divisor. The rules are applied recursively, so
122 * if a substitution is filled in with text that includes another substitution, that
123 * substitution is also filled in.</p>
124 *
125 * <p>This rule covers values up to 999, at which point we add another rule:</p>
126 *
127 * <pre>1000: &lt;&lt; thousand[ &gt;&gt;];</pre>
128 *
129 * <p>Again, the meanings of the brackets and substitution tokens shift because the rule's
130 * base value is a higher power of 10, changing the rule's divisor. This rule can actually be
131 * used all the way up to 999,999. This allows us to finish out the rules as follows:</p>
132 *
133 * <pre> 1,000,000: &lt;&lt; million[ &gt;&gt;];
134 * 1,000,000,000: &lt;&lt; billion[ &gt;&gt;];
135 * 1,000,000,000,000: &lt;&lt; trillion[ &gt;&gt;];
136 * 1,000,000,000,000,000: OUT OF RANGE!;</pre>
137 *
138 * <p>Commas, periods, and spaces can be used in the base values to improve legibility and
139 * are ignored by the rule parser. The last rule in the list is customarily treated as an
140 * &quot;overflow rule,&quot; applying to everything from its base value on up, and often (as
141 * in this example) being used to print out an error message or default representation.
142 * Notice also that the size of the major groupings in large numbers is controlled by the
143 * spacing of the rules: because in English we group numbers by thousand, the higher rules
144 * are separated from each other by a factor of 1,000.</p>
145 *
146 * <p>To see how these rules actually work in practice, consider the following example:
147 * Formatting 25,430 with this rule set would work like this:</p>
148 *
149 * <table border="0" width="100%">
150 *   <tr>
151 *     <td><strong>&lt;&lt; thousand &gt;&gt;</strong></td>
152 *     <td>[the rule whose base value is 1,000 is applicable to 25,340]</td>
153 *   </tr>
154 *   <tr>
155 *     <td><strong>twenty-&gt;&gt;</strong> thousand &gt;&gt;</td>
156 *     <td>[25,340 over 1,000 is 25. The rule for 20 applies.]</td>
157 *   </tr>
158 *   <tr>
159 *     <td>twenty-<strong>five</strong> thousand &gt;&gt;</td>
160 *     <td>[25 mod 10 is 5. The rule for 5 is &quot;five.&quot;</td>
161 *   </tr>
162 *   <tr>
163 *     <td>twenty-five thousand <strong>&lt;&lt; hundred &gt;&gt;</strong></td>
164 *     <td>[25,340 mod 1,000 is 340. The rule for 100 applies.]</td>
165 *   </tr>
166 *   <tr>
167 *     <td>twenty-five thousand <strong>three</strong> hundred &gt;&gt;</td>
168 *     <td>[340 over 100 is 3. The rule for 3 is &quot;three.&quot;]</td>
169 *   </tr>
170 *   <tr>
171 *     <td>twenty-five thousand three hundred <strong>forty</strong></td>
172 *     <td>[340 mod 100 is 40. The rule for 40 applies. Since 40 divides
173 *     evenly by 10, the hyphen and substitution in the brackets are omitted.]</td>
174 *   </tr>
175 * </table>
176 *
177 * <p>The above syntax suffices only to format positive integers. To format negative numbers,
178 * we add a special rule:</p>
179 *
180 * <pre>-x: minus &gt;&gt;;</pre>
181 *
182 * <p>This is called a <em>negative-number rule,</em> and is identified by &quot;-x&quot;
183 * where the base value would be. This rule is used to format all negative numbers. the
184 * &gt;&gt; token here means &quot;find the number's absolute value, format it with these
185 * rules, and put the result here.&quot;</p>
186 *
187 * <p>We also add a special rule called a <em>fraction rule </em>for numbers with fractional
188 * parts:</p>
189 *
190 * <pre>x.x: &lt;&lt; point &gt;&gt;;</pre>
191 *
192 * <p>This rule is used for all positive non-integers (negative non-integers pass through the
193 * negative-number rule first and then through this rule). Here, the &lt;&lt; token refers to
194 * the number's integral part, and the &gt;&gt; to the number's fractional part. The
195 * fractional part is formatted as a series of single-digit numbers (e.g., 123.456 would be
196 * formatted as &quot;one hundred twenty-three point four five six&quot;).</p>
197 *
198 * <p>To see how this rule syntax is applied to various languages, examine the resource data.</p>
199 *
200 * <p>There is actually much more flexibility built into the rule language than the
201 * description above shows. A formatter may own multiple rule sets, which can be selected by
202 * the caller, and which can use each other to fill in their substitutions. Substitutions can
203 * also be filled in with digits, using a DecimalFormat object. There is syntax that can be
204 * used to alter a rule's divisor in various ways. And there is provision for much more
205 * flexible fraction handling. A complete description of the rule syntax follows:</p>
206 *
207 * <hr>
208 *
209 * <p>The description of a <tt>RuleBasedNumberFormat</tt>'s behavior consists of one or more <em>rule
210 * sets.</em> Each rule set consists of a name, a colon, and a list of <em>rules.</em> A rule
211 * set name must begin with a % sign. Rule sets with names that begin with a single % sign
212 * are <em>public:</em> the caller can specify that they be used to format and parse numbers.
213 * Rule sets with names that begin with %% are <em>private:</em> they exist only for the use
214 * of other rule sets. If a formatter only has one rule set, the name may be omitted.</p>
215 *
216 * <p>The user can also specify a special &quot;rule set&quot; named <tt>%%lenient-parse</tt>.
217 * The body of <tt>%%lenient-parse</tt> isn't a set of number-formatting rules, but a <tt>RuleBasedCollator</tt>
218 * description which is used to define equivalences for lenient parsing. For more information
219 * on the syntax, see <tt>RuleBasedCollator</tt>. For more information on lenient parsing,
220 * see <tt>setLenientParse()</tt>.  <em>Note:</em> symbols that have syntactic meaning
221 * in collation rules, such as '&amp;', have no particular meaning when appearing outside
222 * of the <tt>lenient-parse</tt> rule set.</p>
223 *
224 * <p>The body of a rule set consists of an ordered, semicolon-delimited list of <em>rules.</em>
225 * Internally, every rule has a base value, a divisor, rule text, and zero, one, or two <em>substitutions.</em>
226 * These parameters are controlled by the description syntax, which consists of a <em>rule
227 * descriptor,</em> a colon, and a <em>rule body.</em></p>
228 *
229 * <p>A rule descriptor can take one of the following forms (text in <em>italics</em> is the
230 * name of a token):</p>
231 *
232 * <table border="0" width="100%">
233 *   <tr>
234 *     <td><em>bv</em>:</td>
235 *     <td><em>bv</em> specifies the rule's base value. <em>bv</em> is a decimal
236 *     number expressed using ASCII digits. <em>bv</em> may contain spaces, period, and commas,
237 *     which are ignored. The rule's divisor is the highest power of 10 less than or equal to
238 *     the base value.</td>
239 *   </tr>
240 *   <tr>
241 *     <td><em>bv</em>/<em>rad</em>:</td>
242 *     <td><em>bv</em> specifies the rule's base value. The rule's divisor is the
243 *     highest power of <em>rad</em> less than or equal to the base value.</td>
244 *   </tr>
245 *   <tr>
246 *     <td><em>bv</em>&gt;:</td>
247 *     <td><em>bv</em> specifies the rule's base value. To calculate the divisor,
248 *     let the radix be 10, and the exponent be the highest exponent of the radix that yields a
249 *     result less than or equal to the base value. Every &gt; character after the base value
250 *     decreases the exponent by 1. If the exponent is positive or 0, the divisor is the radix
251 *     raised to the power of the exponent; otherwise, the divisor is 1.</td>
252 *   </tr>
253 *   <tr>
254 *     <td><em>bv</em>/<em>rad</em>&gt;:</td>
255 *     <td><em>bv</em> specifies the rule's base value. To calculate the divisor,
256 *     let the radix be <em>rad</em>, and the exponent be the highest exponent of the radix that
257 *     yields a result less than or equal to the base value. Every &gt; character after the radix
258 *     decreases the exponent by 1. If the exponent is positive or 0, the divisor is the radix
259 *     raised to the power of the exponent; otherwise, the divisor is 1.</td>
260 *   </tr>
261 *   <tr>
262 *     <td>-x:</td>
263 *     <td>The rule is a negative-number rule.</td>
264 *   </tr>
265 *   <tr>
266 *     <td>x.x:</td>
267 *     <td>The rule is an <em>improper fraction rule.</em></td>
268 *   </tr>
269 *   <tr>
270 *     <td>0.x:</td>
271 *     <td>The rule is a <em>proper fraction rule.</em></td>
272 *   </tr>
273 *   <tr>
274 *     <td>x.0:</td>
275 *     <td>The rule is a <em>master rule.</em></td>
276 *   </tr>
277 *   <tr>
278 *     <td><em>nothing</em></td>
279 *     <td>If the rule's rule descriptor is left out, the base value is one plus the
280 *     preceding rule's base value (or zero if this is the first rule in the list) in a normal
281 *     rule set.&nbsp; In a fraction rule set, the base value is the same as the preceding rule's
282 *     base value.</td>
283 *   </tr>
284 * </table>
285 *
286 * <p>A rule set may be either a regular rule set or a <em>fraction rule set,</em> depending
287 * on whether it is used to format a number's integral part (or the whole number) or a
288 * number's fractional part. Using a rule set to format a rule's fractional part makes it a
289 * fraction rule set.</p>
290 *
291 * <p>Which rule is used to format a number is defined according to one of the following
292 * algorithms: If the rule set is a regular rule set, do the following:
293 *
294 * <ul>
295 *   <li>If the rule set includes a master rule (and the number was passed in as a <tt>double</tt>),
296 *     use the master rule.&nbsp; (If the number being formatted was passed in as a <tt>long</tt>,
297 *     the master rule is ignored.)</li>
298 *   <li>If the number is negative, use the negative-number rule.</li>
299 *   <li>If the number has a fractional part and is greater than 1, use the improper fraction
300 *     rule.</li>
301 *   <li>If the number has a fractional part and is between 0 and 1, use the proper fraction
302 *     rule.</li>
303 *   <li>Binary-search the rule list for the rule with the highest base value less than or equal
304 *     to the number. If that rule has two substitutions, its base value is not an even multiple
305 *     of its divisor, and the number <em>is</em> an even multiple of the rule's divisor, use the
306 *     rule that precedes it in the rule list. Otherwise, use the rule itself.</li>
307 * </ul>
308 *
309 * <p>If the rule set is a fraction rule set, do the following:
310 *
311 * <ul>
312 *   <li>Ignore negative-number and fraction rules.</li>
313 *   <li>For each rule in the list, multiply the number being formatted (which will always be
314 *     between 0 and 1) by the rule's base value. Keep track of the distance between the result
315 *     the nearest integer.</li>
316 *   <li>Use the rule that produced the result closest to zero in the above calculation. In the
317 *     event of a tie or a direct hit, use the first matching rule encountered. (The idea here is
318 *     to try each rule's base value as a possible denominator of a fraction. Whichever
319 *     denominator produces the fraction closest in value to the number being formatted wins.) If
320 *     the rule following the matching rule has the same base value, use it if the numerator of
321 *     the fraction is anything other than 1; if the numerator is 1, use the original matching
322 *     rule. (This is to allow singular and plural forms of the rule text without a lot of extra
323 *     hassle.)</li>
324 * </ul>
325 *
326 * <p>A rule's body consists of a string of characters terminated by a semicolon. The rule
327 * may include zero, one, or two <em>substitution tokens,</em> and a range of text in
328 * brackets. The brackets denote optional text (and may also include one or both
329 * substitutions). The exact meanings of the substitution tokens, and under what conditions
330 * optional text is omitted, depend on the syntax of the substitution token and the context.
331 * The rest of the text in a rule body is literal text that is output when the rule matches
332 * the number being formatted.</p>
333 *
334 * <p>A substitution token begins and ends with a <em>token character.</em> The token
335 * character and the context together specify a mathematical operation to be performed on the
336 * number being formatted. An optional <em>substitution descriptor </em>specifies how the
337 * value resulting from that operation is used to fill in the substitution. The position of
338 * the substitution token in the rule body specifies the location of the resultant text in
339 * the original rule text.</p>
340 *
341 * <p>The meanings of the substitution token characters are as follows:</p>
342 *
343 * <table border="0" width="100%">
344 *   <tr>
345 *     <td>&gt;&gt;</td>
346 *     <td>in normal rule</td>
347 *     <td>Divide the number by the rule's divisor and format the remainder</td>
348 *   </tr>
349 *   <tr>
350 *     <td></td>
351 *     <td>in negative-number rule</td>
352 *     <td>Find the absolute value of the number and format the result</td>
353 *   </tr>
354 *   <tr>
355 *     <td></td>
356 *     <td>in fraction or master rule</td>
357 *     <td>Isolate the number's fractional part and format it.</td>
358 *   </tr>
359 *   <tr>
360 *     <td></td>
361 *     <td>in rule in fraction rule set</td>
362 *     <td>Not allowed.</td>
363 *   </tr>
364 *   <tr>
365 *     <td>&gt;&gt;&gt;</td>
366 *     <td>in normal rule</td>
367 *     <td>Divide the number by the rule's divisor and format the remainder,
368 *       but bypass the normal rule-selection process and just use the
369 *       rule that precedes this one in this rule list.</td>
370 *   </tr>
371 *   <tr>
372 *     <td></td>
373 *     <td>in all other rules</td>
374 *     <td>Not allowed.</td>
375 *   </tr>
376 *   <tr>
377 *     <td>&lt;&lt;</td>
378 *     <td>in normal rule</td>
379 *     <td>Divide the number by the rule's divisor and format the quotient</td>
380 *   </tr>
381 *   <tr>
382 *     <td></td>
383 *     <td>in negative-number rule</td>
384 *     <td>Not allowed.</td>
385 *   </tr>
386 *   <tr>
387 *     <td></td>
388 *     <td>in fraction or master rule</td>
389 *     <td>Isolate the number's integral part and format it.</td>
390 *   </tr>
391 *   <tr>
392 *     <td></td>
393 *     <td>in rule in fraction rule set</td>
394 *     <td>Multiply the number by the rule's base value and format the result.</td>
395 *   </tr>
396 *   <tr>
397 *     <td>==</td>
398 *     <td>in all rule sets</td>
399 *     <td>Format the number unchanged</td>
400 *   </tr>
401 *   <tr>
402 *     <td>[]</td>
403 *     <td>in normal rule</td>
404 *     <td>Omit the optional text if the number is an even multiple of the rule's divisor</td>
405 *   </tr>
406 *   <tr>
407 *     <td></td>
408 *     <td>in negative-number rule</td>
409 *     <td>Not allowed.</td>
410 *   </tr>
411 *   <tr>
412 *     <td></td>
413 *     <td>in improper-fraction rule</td>
414 *     <td>Omit the optional text if the number is between 0 and 1 (same as specifying both an
415 *     x.x rule and a 0.x rule)</td>
416 *   </tr>
417 *   <tr>
418 *     <td></td>
419 *     <td>in master rule</td>
420 *     <td>Omit the optional text if the number is an integer (same as specifying both an x.x
421 *     rule and an x.0 rule)</td>
422 *   </tr>
423 *   <tr>
424 *     <td></td>
425 *     <td>in proper-fraction rule</td>
426 *     <td>Not allowed.</td>
427 *   </tr>
428 *   <tr>
429 *     <td></td>
430 *     <td>in rule in fraction rule set</td>
431 *     <td>Omit the optional text if multiplying the number by the rule's base value yields 1.</td>
432 *   </tr>
433 *   <tr>
434 *     <td width="37">$(cardinal,<i>plural syntax</i>)$</td>
435 *     <td width="23"></td>
436 *     <td width="165" valign="top">in all rule sets</td>
437 *     <td>This provides the ability to choose a word based on the number divided by the radix to the power of the
438 *     exponent of the base value for the specified locale, which is normally equivalent to the &lt;&lt; value.
439 *     This uses the cardinal plural rules from PluralFormat. All strings used in the plural format are treated
440 *     as the same base value for parsing.</td>
441 *   </tr>
442 *   <tr>
443 *     <td width="37">$(ordinal,<i>plural syntax</i>)$</td>
444 *     <td width="23"></td>
445 *     <td width="165" valign="top">in all rule sets</td>
446 *     <td>This provides the ability to choose a word based on the number divided by the radix to the power of the
447 *     exponent of the base value for the specified locale, which is normally equivalent to the &lt;&lt; value.
448 *     This uses the ordinal plural rules from PluralFormat. All strings used in the plural format are treated
449 *     as the same base value for parsing.</td>
450 *   </tr>
451 * </table>
452 *
453 * <p>The substitution descriptor (i.e., the text between the token characters) may take one
454 * of three forms:</p>
455 *
456 * <table border="0" width="100%">
457 *   <tr>
458 *     <td>a rule set name</td>
459 *     <td>Perform the mathematical operation on the number, and format the result using the
460 *     named rule set.</td>
461 *   </tr>
462 *   <tr>
463 *     <td>a DecimalFormat pattern</td>
464 *     <td>Perform the mathematical operation on the number, and format the result using a
465 *     DecimalFormat with the specified pattern.&nbsp; The pattern must begin with 0 or #.</td>
466 *   </tr>
467 *   <tr>
468 *     <td>nothing</td>
469 *     <td>Perform the mathematical operation on the number, and format the result using the rule
470 *     set containing the current rule, except:
471 *     <ul>
472 *       <li>You can't have an empty substitution descriptor with a == substitution.</li>
473 *       <li>If you omit the substitution descriptor in a &gt;&gt; substitution in a fraction rule,
474 *         format the result one digit at a time using the rule set containing the current rule.</li>
475 *       <li>If you omit the substitution descriptor in a &lt;&lt; substitution in a rule in a
476 *         fraction rule set, format the result using the default rule set for this formatter.</li>
477 *     </ul>
478 *     </td>
479 *   </tr>
480 * </table>
481 *
482 * <p>Whitespace is ignored between a rule set name and a rule set body, between a rule
483 * descriptor and a rule body, or between rules. If a rule body begins with an apostrophe,
484 * the apostrophe is ignored, but all text after it becomes significant (this is how you can
485 * have a rule's rule text begin with whitespace). There is no escape function: the semicolon
486 * is not allowed in rule set names or in rule text, and the colon is not allowed in rule set
487 * names. The characters beginning a substitution token are always treated as the beginning
488 * of a substitution token.</p>
489 *
490 * <p>See the resource data and the demo program for annotated examples of real rule sets
491 * using these features.</p>
492 *
493 * <p><em>User subclasses are not supported.</em> While clients may write
494 * subclasses, such code will not necessarily work and will not be
495 * guaranteed to work stably from release to release.
496 *
497 * <p><b>Localizations</b></p>
498 * <p>Constructors are available that allow the specification of localizations for the
499 * public rule sets (and also allow more control over what public rule sets are available).
500 * Localization data is represented as a textual description.  The description represents
501 * an array of arrays of string.  The first element is an array of the public rule set names,
502 * each of these must be one of the public rule set names that appear in the rules.  Only
503 * names in this array will be treated as public rule set names by the API.  Each subsequent
504 * element is an array of localizations of these names.  The first element of one of these
505 * subarrays is the locale name, and the remaining elements are localizations of the
506 * public rule set names, in the same order as they were listed in the first arrray.</p>
507 * <p>In the syntax, angle brackets '<', '>' are used to delimit the arrays, and comma ',' is used
508 * to separate elements of an array.  Whitespace is ignored, unless quoted.</p>
509 * <p>For example:<pre>
510 * < < %foo, %bar, %baz >,
511 *   < en, Foo, Bar, Baz >,
512 *   < fr, 'le Foo', 'le Bar', 'le Baz' >
513 *   < zh, \\u7532, \\u4e59, \\u4e19 > >
514 * </pre></p>
515 * @author Richard Gillam
516 * @see NumberFormat
517 * @see DecimalFormat
518 * @see PluralFormat
519 * @see PluralRules
520 * @stable ICU 2.0
521 */
522class U_I18N_API RuleBasedNumberFormat : public NumberFormat {
523public:
524
525  //-----------------------------------------------------------------------
526  // constructors
527  //-----------------------------------------------------------------------
528
529    /**
530     * Creates a RuleBasedNumberFormat that behaves according to the description
531     * passed in.  The formatter uses the default locale.
532     * @param rules A description of the formatter's desired behavior.
533     * See the class documentation for a complete explanation of the description
534     * syntax.
535     * @param perror The parse error if an error was encountered.
536     * @param status The status indicating whether the constructor succeeded.
537     * @stable ICU 3.2
538     */
539    RuleBasedNumberFormat(const UnicodeString& rules, UParseError& perror, UErrorCode& status);
540
541    /**
542     * Creates a RuleBasedNumberFormat that behaves according to the description
543     * passed in.  The formatter uses the default locale.
544     * <p>
545     * The localizations data provides information about the public
546     * rule sets and their localized display names for different
547     * locales. The first element in the list is an array of the names
548     * of the public rule sets.  The first element in this array is
549     * the initial default ruleset.  The remaining elements in the
550     * list are arrays of localizations of the names of the public
551     * rule sets.  Each of these is one longer than the initial array,
552     * with the first String being the ULocale ID, and the remaining
553     * Strings being the localizations of the rule set names, in the
554     * same order as the initial array.  Arrays are NULL-terminated.
555     * @param rules A description of the formatter's desired behavior.
556     * See the class documentation for a complete explanation of the description
557     * syntax.
558     * @param localizations the localization information.
559     * names in the description.  These will be copied by the constructor.
560     * @param perror The parse error if an error was encountered.
561     * @param status The status indicating whether the constructor succeeded.
562     * @stable ICU 3.2
563     */
564    RuleBasedNumberFormat(const UnicodeString& rules, const UnicodeString& localizations,
565                        UParseError& perror, UErrorCode& status);
566
567  /**
568   * Creates a RuleBasedNumberFormat that behaves according to the rules
569   * passed in.  The formatter uses the specified locale to determine the
570   * characters to use when formatting numerals, and to define equivalences
571   * for lenient parsing.
572   * @param rules The formatter rules.
573   * See the class documentation for a complete explanation of the rule
574   * syntax.
575   * @param locale A locale that governs which characters are used for
576   * formatting values in numerals and which characters are equivalent in
577   * lenient parsing.
578   * @param perror The parse error if an error was encountered.
579   * @param status The status indicating whether the constructor succeeded.
580   * @stable ICU 2.0
581   */
582  RuleBasedNumberFormat(const UnicodeString& rules, const Locale& locale,
583                        UParseError& perror, UErrorCode& status);
584
585    /**
586     * Creates a RuleBasedNumberFormat that behaves according to the description
587     * passed in.  The formatter uses the default locale.
588     * <p>
589     * The localizations data provides information about the public
590     * rule sets and their localized display names for different
591     * locales. The first element in the list is an array of the names
592     * of the public rule sets.  The first element in this array is
593     * the initial default ruleset.  The remaining elements in the
594     * list are arrays of localizations of the names of the public
595     * rule sets.  Each of these is one longer than the initial array,
596     * with the first String being the ULocale ID, and the remaining
597     * Strings being the localizations of the rule set names, in the
598     * same order as the initial array.  Arrays are NULL-terminated.
599     * @param rules A description of the formatter's desired behavior.
600     * See the class documentation for a complete explanation of the description
601     * syntax.
602     * @param localizations a list of localizations for the rule set
603     * names in the description.  These will be copied by the constructor.
604     * @param locale A locale that governs which characters are used for
605     * formatting values in numerals and which characters are equivalent in
606     * lenient parsing.
607     * @param perror The parse error if an error was encountered.
608     * @param status The status indicating whether the constructor succeeded.
609     * @stable ICU 3.2
610     */
611    RuleBasedNumberFormat(const UnicodeString& rules, const UnicodeString& localizations,
612                        const Locale& locale, UParseError& perror, UErrorCode& status);
613
614  /**
615   * Creates a RuleBasedNumberFormat from a predefined ruleset.  The selector
616   * code choosed among three possible predefined formats: spellout, ordinal,
617   * and duration.
618   * @param tag A selector code specifying which kind of formatter to create for that
619   * locale.  There are four legal values: URBNF_SPELLOUT, which creates a formatter that
620   * spells out a value in words in the desired language, URBNF_ORDINAL, which attaches
621   * an ordinal suffix from the desired language to the end of a number (e.g. "123rd"),
622   * URBNF_DURATION, which formats a duration in seconds as hours, minutes, and seconds always rounding down,
623   * and URBNF_NUMBERING_SYSTEM, which is used to invoke rules for alternate numbering
624   * systems such as the Hebrew numbering system, or for Roman Numerals, etc.
625   * @param locale The locale for the formatter.
626   * @param status The status indicating whether the constructor succeeded.
627   * @stable ICU 2.0
628   */
629  RuleBasedNumberFormat(URBNFRuleSetTag tag, const Locale& locale, UErrorCode& status);
630
631  //-----------------------------------------------------------------------
632  // boilerplate
633  //-----------------------------------------------------------------------
634
635  /**
636   * Copy constructor
637   * @param rhs    the object to be copied from.
638   * @stable ICU 2.6
639   */
640  RuleBasedNumberFormat(const RuleBasedNumberFormat& rhs);
641
642  /**
643   * Assignment operator
644   * @param rhs    the object to be copied from.
645   * @stable ICU 2.6
646   */
647  RuleBasedNumberFormat& operator=(const RuleBasedNumberFormat& rhs);
648
649  /**
650   * Release memory allocated for a RuleBasedNumberFormat when you are finished with it.
651   * @stable ICU 2.6
652   */
653  virtual ~RuleBasedNumberFormat();
654
655  /**
656   * Clone this object polymorphically.  The caller is responsible
657   * for deleting the result when done.
658   * @return  A copy of the object.
659   * @stable ICU 2.6
660   */
661  virtual Format* clone(void) const;
662
663  /**
664   * Return true if the given Format objects are semantically equal.
665   * Objects of different subclasses are considered unequal.
666   * @param other    the object to be compared with.
667   * @return        true if the given Format objects are semantically equal.
668   * @stable ICU 2.6
669   */
670  virtual UBool operator==(const Format& other) const;
671
672//-----------------------------------------------------------------------
673// public API functions
674//-----------------------------------------------------------------------
675
676  /**
677   * return the rules that were provided to the RuleBasedNumberFormat.
678   * @return the result String that was passed in
679   * @stable ICU 2.0
680   */
681  virtual UnicodeString getRules() const;
682
683  /**
684   * Return the number of public rule set names.
685   * @return the number of public rule set names.
686   * @stable ICU 2.0
687   */
688  virtual int32_t getNumberOfRuleSetNames() const;
689
690  /**
691   * Return the name of the index'th public ruleSet.  If index is not valid,
692   * the function returns null.
693   * @param index the index of the ruleset
694   * @return the name of the index'th public ruleSet.
695   * @stable ICU 2.0
696   */
697  virtual UnicodeString getRuleSetName(int32_t index) const;
698
699  /**
700   * Return the number of locales for which we have localized rule set display names.
701   * @return the number of locales for which we have localized rule set display names.
702   * @stable ICU 3.2
703   */
704  virtual int32_t getNumberOfRuleSetDisplayNameLocales(void) const;
705
706  /**
707   * Return the index'th display name locale.
708   * @param index the index of the locale
709   * @param status set to a failure code when this function fails
710   * @return the locale
711   * @see #getNumberOfRuleSetDisplayNameLocales
712   * @stable ICU 3.2
713   */
714  virtual Locale getRuleSetDisplayNameLocale(int32_t index, UErrorCode& status) const;
715
716    /**
717     * Return the rule set display names for the provided locale.  These are in the same order
718     * as those returned by getRuleSetName.  The locale is matched against the locales for
719     * which there is display name data, using normal fallback rules.  If no locale matches,
720     * the default display names are returned.  (These are the internal rule set names minus
721     * the leading '%'.)
722     * @param index the index of the rule set
723     * @param locale the locale (returned by getRuleSetDisplayNameLocales) for which the localized
724     * display name is desired
725     * @return the display name for the given index, which might be bogus if there is an error
726     * @see #getRuleSetName
727     * @stable ICU 3.2
728     */
729  virtual UnicodeString getRuleSetDisplayName(int32_t index,
730                          const Locale& locale = Locale::getDefault());
731
732    /**
733     * Return the rule set display name for the provided rule set and locale.
734     * The locale is matched against the locales for which there is display name data, using
735     * normal fallback rules.  If no locale matches, the default display name is returned.
736     * @return the display name for the rule set
737     * @stable ICU 3.2
738     * @see #getRuleSetDisplayName
739     */
740  virtual UnicodeString getRuleSetDisplayName(const UnicodeString& ruleSetName,
741                          const Locale& locale = Locale::getDefault());
742
743
744  using NumberFormat::format;
745
746  /**
747   * Formats the specified 32-bit number using the default ruleset.
748   * @param number The number to format.
749   * @param toAppendTo the string that will hold the (appended) result
750   * @param pos the fieldposition
751   * @return A textual representation of the number.
752   * @stable ICU 2.0
753   */
754  virtual UnicodeString& format(int32_t number,
755                                UnicodeString& toAppendTo,
756                                FieldPosition& pos) const;
757
758  /**
759   * Formats the specified 64-bit number using the default ruleset.
760   * @param number The number to format.
761   * @param toAppendTo the string that will hold the (appended) result
762   * @param pos the fieldposition
763   * @return A textual representation of the number.
764   * @stable ICU 2.1
765   */
766  virtual UnicodeString& format(int64_t number,
767                                UnicodeString& toAppendTo,
768                                FieldPosition& pos) const;
769  /**
770   * Formats the specified number using the default ruleset.
771   * @param number The number to format.
772   * @param toAppendTo the string that will hold the (appended) result
773   * @param pos the fieldposition
774   * @return A textual representation of the number.
775   * @stable ICU 2.0
776   */
777  virtual UnicodeString& format(double number,
778                                UnicodeString& toAppendTo,
779                                FieldPosition& pos) const;
780
781  /**
782   * Formats the specified number using the named ruleset.
783   * @param number The number to format.
784   * @param ruleSetName The name of the rule set to format the number with.
785   * This must be the name of a valid public rule set for this formatter.
786   * @param toAppendTo the string that will hold the (appended) result
787   * @param pos the fieldposition
788   * @param status the status
789   * @return A textual representation of the number.
790   * @stable ICU 2.0
791   */
792  virtual UnicodeString& format(int32_t number,
793                                const UnicodeString& ruleSetName,
794                                UnicodeString& toAppendTo,
795                                FieldPosition& pos,
796                                UErrorCode& status) const;
797  /**
798   * Formats the specified 64-bit number using the named ruleset.
799   * @param number The number to format.
800   * @param ruleSetName The name of the rule set to format the number with.
801   * This must be the name of a valid public rule set for this formatter.
802   * @param toAppendTo the string that will hold the (appended) result
803   * @param pos the fieldposition
804   * @param status the status
805   * @return A textual representation of the number.
806   * @stable ICU 2.1
807   */
808  virtual UnicodeString& format(int64_t number,
809                                const UnicodeString& ruleSetName,
810                                UnicodeString& toAppendTo,
811                                FieldPosition& pos,
812                                UErrorCode& status) const;
813  /**
814   * Formats the specified number using the named ruleset.
815   * @param number The number to format.
816   * @param ruleSetName The name of the rule set to format the number with.
817   * This must be the name of a valid public rule set for this formatter.
818   * @param toAppendTo the string that will hold the (appended) result
819   * @param pos the fieldposition
820   * @param status the status
821   * @return A textual representation of the number.
822   * @stable ICU 2.0
823   */
824  virtual UnicodeString& format(double number,
825                                const UnicodeString& ruleSetName,
826                                UnicodeString& toAppendTo,
827                                FieldPosition& pos,
828                                UErrorCode& status) const;
829
830  using NumberFormat::parse;
831
832  /**
833   * Parses the specfied string, beginning at the specified position, according
834   * to this formatter's rules.  This will match the string against all of the
835   * formatter's public rule sets and return the value corresponding to the longest
836   * parseable substring.  This function's behavior is affected by the lenient
837   * parse mode.
838   * @param text The string to parse
839   * @param result the result of the parse, either a double or a long.
840   * @param parsePosition On entry, contains the position of the first character
841   * in "text" to examine.  On exit, has been updated to contain the position
842   * of the first character in "text" that wasn't consumed by the parse.
843   * @see #setLenient
844   * @stable ICU 2.0
845   */
846  virtual void parse(const UnicodeString& text,
847                     Formattable& result,
848                     ParsePosition& parsePosition) const;
849
850#if !UCONFIG_NO_COLLATION
851
852  /**
853   * Turns lenient parse mode on and off.
854   *
855   * When in lenient parse mode, the formatter uses a Collator for parsing the text.
856   * Only primary differences are treated as significant.  This means that case
857   * differences, accent differences, alternate spellings of the same letter
858   * (e.g., ae and a-umlaut in German), ignorable characters, etc. are ignored in
859   * matching the text.  In many cases, numerals will be accepted in place of words
860   * or phrases as well.
861   *
862   * For example, all of the following will correctly parse as 255 in English in
863   * lenient-parse mode:
864   * <br>"two hundred fifty-five"
865   * <br>"two hundred fifty five"
866   * <br>"TWO HUNDRED FIFTY-FIVE"
867   * <br>"twohundredfiftyfive"
868   * <br>"2 hundred fifty-5"
869   *
870   * The Collator used is determined by the locale that was
871   * passed to this object on construction.  The description passed to this object
872   * on construction may supply additional collation rules that are appended to the
873   * end of the default collator for the locale, enabling additional equivalences
874   * (such as adding more ignorable characters or permitting spelled-out version of
875   * symbols; see the demo program for examples).
876   *
877   * It's important to emphasize that even strict parsing is relatively lenient: it
878   * will accept some text that it won't produce as output.  In English, for example,
879   * it will correctly parse "two hundred zero" and "fifteen hundred".
880   *
881   * @param enabled If true, turns lenient-parse mode on; if false, turns it off.
882   * @see RuleBasedCollator
883   * @stable ICU 2.0
884   */
885  virtual void setLenient(UBool enabled);
886
887  /**
888   * Returns true if lenient-parse mode is turned on.  Lenient parsing is off
889   * by default.
890   * @return true if lenient-parse mode is turned on.
891   * @see #setLenient
892   * @stable ICU 2.0
893   */
894  virtual inline UBool isLenient(void) const;
895
896#endif
897
898  /**
899   * Override the default rule set to use.  If ruleSetName is null, reset
900   * to the initial default rule set.  If the rule set is not a public rule set name,
901   * U_ILLEGAL_ARGUMENT_ERROR is returned in status.
902   * @param ruleSetName the name of the rule set, or null to reset the initial default.
903   * @param status set to failure code when a problem occurs.
904   * @stable ICU 2.6
905   */
906  virtual void setDefaultRuleSet(const UnicodeString& ruleSetName, UErrorCode& status);
907
908  /**
909   * Return the name of the current default rule set.  If the current rule set is
910   * not public, returns a bogus (and empty) UnicodeString.
911   * @return the name of the current default rule set
912   * @stable ICU 3.0
913   */
914  virtual UnicodeString getDefaultRuleSetName() const;
915
916  /**
917   * Set a particular UDisplayContext value in the formatter, such as
918   * UDISPCTX_CAPITALIZATION_FOR_STANDALONE. Note: For getContext, see
919   * NumberFormat.
920   * @param value The UDisplayContext value to set.
921   * @param status Input/output status. If at entry this indicates a failure
922   *               status, the function will do nothing; otherwise this will be
923   *               updated with any new status from the function.
924   * @stable ICU 53
925   */
926  virtual void setContext(UDisplayContext value, UErrorCode& status);
927
928public:
929    /**
930     * ICU "poor man's RTTI", returns a UClassID for this class.
931     *
932     * @stable ICU 2.8
933     */
934    static UClassID U_EXPORT2 getStaticClassID(void);
935
936    /**
937     * ICU "poor man's RTTI", returns a UClassID for the actual class.
938     *
939     * @stable ICU 2.8
940     */
941    virtual UClassID getDynamicClassID(void) const;
942
943    /**
944     * Sets the decimal format symbols, which is generally not changed
945     * by the programmer or user. The formatter takes ownership of
946     * symbolsToAdopt; the client must not delete it.
947     *
948     * @param symbolsToAdopt DecimalFormatSymbols to be adopted.
949     * @stable ICU 49
950     */
951    virtual void adoptDecimalFormatSymbols(DecimalFormatSymbols* symbolsToAdopt);
952
953    /**
954     * Sets the decimal format symbols, which is generally not changed
955     * by the programmer or user. A clone of the symbols is created and
956     * the symbols is _not_ adopted; the client is still responsible for
957     * deleting it.
958     *
959     * @param symbols DecimalFormatSymbols.
960     * @stable ICU 49
961     */
962    virtual void setDecimalFormatSymbols(const DecimalFormatSymbols& symbols);
963
964private:
965    RuleBasedNumberFormat(); // default constructor not implemented
966
967    // this will ref the localizations if they are not NULL
968    // caller must deref to get adoption
969    RuleBasedNumberFormat(const UnicodeString& description, LocalizationInfo* localizations,
970              const Locale& locale, UParseError& perror, UErrorCode& status);
971
972    void init(const UnicodeString& rules, LocalizationInfo* localizations, UParseError& perror, UErrorCode& status);
973    void initCapitalizationContextInfo(const Locale& thelocale);
974    void dispose();
975    void stripWhitespace(UnicodeString& src);
976    void initDefaultRuleSet();
977    void format(double number, NFRuleSet& ruleSet);
978    NFRuleSet* findRuleSet(const UnicodeString& name, UErrorCode& status) const;
979
980    /* friend access */
981    friend class NFSubstitution;
982    friend class NFRule;
983    friend class FractionalPartSubstitution;
984
985    inline NFRuleSet * getDefaultRuleSet() const;
986    const RuleBasedCollator * getCollator() const;
987    DecimalFormatSymbols * getDecimalFormatSymbols() const;
988    PluralFormat *createPluralFormat(UPluralType pluralType, const UnicodeString &pattern, UErrorCode& status) const;
989    UnicodeString& adjustForCapitalizationContext(int32_t startPos, UnicodeString& currentResult) const;
990
991private:
992    NFRuleSet **ruleSets;
993    UnicodeString* ruleSetDescriptions;
994    int32_t numRuleSets;
995    NFRuleSet *defaultRuleSet;
996    Locale locale;
997    RuleBasedCollator* collator;
998    DecimalFormatSymbols* decimalFormatSymbols;
999    UBool lenient;
1000    UnicodeString* lenientParseRules;
1001    LocalizationInfo* localizations;
1002    UnicodeString originalDescription;
1003    UBool capitalizationInfoSet;
1004    UBool capitalizationForUIListMenu;
1005    UBool capitalizationForStandAlone;
1006    BreakIterator* capitalizationBrkIter;
1007};
1008
1009// ---------------
1010
1011#if !UCONFIG_NO_COLLATION
1012
1013inline UBool
1014RuleBasedNumberFormat::isLenient(void) const {
1015    return lenient;
1016}
1017
1018#endif
1019
1020inline NFRuleSet*
1021RuleBasedNumberFormat::getDefaultRuleSet() const {
1022    return defaultRuleSet;
1023}
1024
1025U_NAMESPACE_END
1026
1027/* U_HAVE_RBNF */
1028#endif
1029
1030/* RBNF_H */
1031#endif
1032