1/*
2*******************************************************************************
3* Copyright (C) 1997-2010, 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/coll.h"
31#include "unicode/dcfmtsym.h"
32#include "unicode/fmtable.h"
33#include "unicode/locid.h"
34#include "unicode/numfmt.h"
35#include "unicode/unistr.h"
36#include "unicode/strenum.h"
37
38U_NAMESPACE_BEGIN
39
40class NFRuleSet;
41class LocalizationInfo;
42
43/**
44 * Tags for the predefined rulesets.
45 *
46 * @stable ICU 2.2
47 */
48enum URBNFRuleSetTag {
49    URBNF_SPELLOUT,
50    URBNF_ORDINAL,
51    URBNF_DURATION,
52    URBNF_NUMBERING_SYSTEM,
53    URBNF_COUNT
54};
55
56#if UCONFIG_NO_COLLATION
57class Collator;
58#endif
59
60/**
61 * The RuleBasedNumberFormat class formats numbers according to a set of rules. This number formatter is
62 * typically used for spelling out numeric values in words (e.g., 25,3476 as
63 * "twenty-five thousand three hundred seventy-six" or "vingt-cinq mille trois
64 * cents soixante-seize" or
65 * "fünfundzwanzigtausenddreihundertsechsundsiebzig"), but can also be used for
66 * other complicated formatting tasks, such as formatting a number of seconds as hours,
67 * minutes and seconds (e.g., 3,730 as "1:02:10").
68 *
69 * <p>The resources contain three predefined formatters for each locale: spellout, which
70 * spells out a value in words (123 is &quot;one hundred twenty-three&quot;); ordinal, which
71 * appends an ordinal suffix to the end of a numeral (123 is &quot;123rd&quot;); and
72 * duration, which shows a duration in seconds as hours, minutes, and seconds (123 is
73 * &quot;2:03&quot;).&nbsp; The client can also define more specialized <tt>RuleBasedNumberFormat</tt>s
74 * by supplying programmer-defined rule sets.</p>
75 *
76 * <p>The behavior of a <tt>RuleBasedNumberFormat</tt> is specified by a textual description
77 * that is either passed to the constructor as a <tt>String</tt> or loaded from a resource
78 * bundle. In its simplest form, the description consists of a semicolon-delimited list of <em>rules.</em>
79 * Each rule has a string of output text and a value or range of values it is applicable to.
80 * In a typical spellout rule set, the first twenty rules are the words for the numbers from
81 * 0 to 19:</p>
82 *
83 * <pre>zero; one; two; three; four; five; six; seven; eight; nine;
84 * ten; eleven; twelve; thirteen; fourteen; fifteen; sixteen; seventeen; eighteen; nineteen;</pre>
85 *
86 * <p>For larger numbers, we can use the preceding set of rules to format the ones place, and
87 * we only have to supply the words for the multiples of 10:</p>
88 *
89 * <pre> 20: twenty[-&gt;&gt;];
90 * 30: thirty[-&gt;&gt;];
91 * 40: forty[-&gt;&gt;];
92 * 50: fifty[-&gt;&gt;];
93 * 60: sixty[-&gt;&gt;];
94 * 70: seventy[-&gt;&gt;];
95 * 80: eighty[-&gt;&gt;];
96 * 90: ninety[-&gt;&gt;];</pre>
97 *
98 * <p>In these rules, the <em>base value</em> is spelled out explicitly and set off from the
99 * rule's output text with a colon. The rules are in a sorted list, and a rule is applicable
100 * to all numbers from its own base value to one less than the next rule's base value. The
101 * &quot;&gt;&gt;&quot; token is called a <em>substitution</em> and tells the fomatter to
102 * isolate the number's ones digit, format it using this same set of rules, and place the
103 * result at the position of the &quot;&gt;&gt;&quot; token. Text in brackets is omitted if
104 * the number being formatted is an even multiple of 10 (the hyphen is a literal hyphen; 24
105 * is &quot;twenty-four,&quot; not &quot;twenty four&quot;).</p>
106 *
107 * <p>For even larger numbers, we can actually look up several parts of the number in the
108 * list:</p>
109 *
110 * <pre>100: &lt;&lt; hundred[ &gt;&gt;];</pre>
111 *
112 * <p>The &quot;&lt;&lt;&quot; represents a new kind of substitution. The &lt;&lt; isolates
113 * the hundreds digit (and any digits to its left), formats it using this same rule set, and
114 * places the result where the &quot;&lt;&lt;&quot; was. Notice also that the meaning of
115 * &gt;&gt; has changed: it now refers to both the tens and the ones digits. The meaning of
116 * both substitutions depends on the rule's base value. The base value determines the rule's <em>divisor,</em>
117 * which is the highest power of 10 that is less than or equal to the base value (the user
118 * can change this). To fill in the substitutions, the formatter divides the number being
119 * formatted by the divisor. The integral quotient is used to fill in the &lt;&lt;
120 * substitution, and the remainder is used to fill in the &gt;&gt; substitution. The meaning
121 * of the brackets changes similarly: text in brackets is omitted if the value being
122 * formatted is an even multiple of the rule's divisor. The rules are applied recursively, so
123 * if a substitution is filled in with text that includes another substitution, that
124 * substitution is also filled in.</p>
125 *
126 * <p>This rule covers values up to 999, at which point we add another rule:</p>
127 *
128 * <pre>1000: &lt;&lt; thousand[ &gt;&gt;];</pre>
129 *
130 * <p>Again, the meanings of the brackets and substitution tokens shift because the rule's
131 * base value is a higher power of 10, changing the rule's divisor. This rule can actually be
132 * used all the way up to 999,999. This allows us to finish out the rules as follows:</p>
133 *
134 * <pre> 1,000,000: &lt;&lt; million[ &gt;&gt;];
135 * 1,000,000,000: &lt;&lt; billion[ &gt;&gt;];
136 * 1,000,000,000,000: &lt;&lt; trillion[ &gt;&gt;];
137 * 1,000,000,000,000,000: OUT OF RANGE!;</pre>
138 *
139 * <p>Commas, periods, and spaces can be used in the base values to improve legibility and
140 * are ignored by the rule parser. The last rule in the list is customarily treated as an
141 * &quot;overflow rule,&quot; applying to everything from its base value on up, and often (as
142 * in this example) being used to print out an error message or default representation.
143 * Notice also that the size of the major groupings in large numbers is controlled by the
144 * spacing of the rules: because in English we group numbers by thousand, the higher rules
145 * are separated from each other by a factor of 1,000.</p>
146 *
147 * <p>To see how these rules actually work in practice, consider the following example:
148 * Formatting 25,430 with this rule set would work like this:</p>
149 *
150 * <table border="0" width="100%">
151 *   <tr>
152 *     <td><strong>&lt;&lt; thousand &gt;&gt;</strong></td>
153 *     <td>[the rule whose base value is 1,000 is applicable to 25,340]</td>
154 *   </tr>
155 *   <tr>
156 *     <td><strong>twenty-&gt;&gt;</strong> thousand &gt;&gt;</td>
157 *     <td>[25,340 over 1,000 is 25. The rule for 20 applies.]</td>
158 *   </tr>
159 *   <tr>
160 *     <td>twenty-<strong>five</strong> thousand &gt;&gt;</td>
161 *     <td>[25 mod 10 is 5. The rule for 5 is &quot;five.&quot;</td>
162 *   </tr>
163 *   <tr>
164 *     <td>twenty-five thousand <strong>&lt;&lt; hundred &gt;&gt;</strong></td>
165 *     <td>[25,340 mod 1,000 is 340. The rule for 100 applies.]</td>
166 *   </tr>
167 *   <tr>
168 *     <td>twenty-five thousand <strong>three</strong> hundred &gt;&gt;</td>
169 *     <td>[340 over 100 is 3. The rule for 3 is &quot;three.&quot;]</td>
170 *   </tr>
171 *   <tr>
172 *     <td>twenty-five thousand three hundred <strong>forty</strong></td>
173 *     <td>[340 mod 100 is 40. The rule for 40 applies. Since 40 divides
174 *     evenly by 10, the hyphen and substitution in the brackets are omitted.]</td>
175 *   </tr>
176 * </table>
177 *
178 * <p>The above syntax suffices only to format positive integers. To format negative numbers,
179 * we add a special rule:</p>
180 *
181 * <pre>-x: minus &gt;&gt;;</pre>
182 *
183 * <p>This is called a <em>negative-number rule,</em> and is identified by &quot;-x&quot;
184 * where the base value would be. This rule is used to format all negative numbers. the
185 * &gt;&gt; token here means &quot;find the number's absolute value, format it with these
186 * rules, and put the result here.&quot;</p>
187 *
188 * <p>We also add a special rule called a <em>fraction rule </em>for numbers with fractional
189 * parts:</p>
190 *
191 * <pre>x.x: &lt;&lt; point &gt;&gt;;</pre>
192 *
193 * <p>This rule is used for all positive non-integers (negative non-integers pass through the
194 * negative-number rule first and then through this rule). Here, the &lt;&lt; token refers to
195 * the number's integral part, and the &gt;&gt; to the number's fractional part. The
196 * fractional part is formatted as a series of single-digit numbers (e.g., 123.456 would be
197 * formatted as &quot;one hundred twenty-three point four five six&quot;).</p>
198 *
199 * <p>To see how this rule syntax is applied to various languages, examine the resource data.</p>
200 *
201 * <p>There is actually much more flexibility built into the rule language than the
202 * description above shows. A formatter may own multiple rule sets, which can be selected by
203 * the caller, and which can use each other to fill in their substitutions. Substitutions can
204 * also be filled in with digits, using a DecimalFormat object. There is syntax that can be
205 * used to alter a rule's divisor in various ways. And there is provision for much more
206 * flexible fraction handling. A complete description of the rule syntax follows:</p>
207 *
208 * <hr>
209 *
210 * <p>The description of a <tt>RuleBasedNumberFormat</tt>'s behavior consists of one or more <em>rule
211 * sets.</em> Each rule set consists of a name, a colon, and a list of <em>rules.</em> A rule
212 * set name must begin with a % sign. Rule sets with names that begin with a single % sign
213 * are <em>public:</em> the caller can specify that they be used to format and parse numbers.
214 * Rule sets with names that begin with %% are <em>private:</em> they exist only for the use
215 * of other rule sets. If a formatter only has one rule set, the name may be omitted.</p>
216 *
217 * <p>The user can also specify a special &quot;rule set&quot; named <tt>%%lenient-parse</tt>.
218 * The body of <tt>%%lenient-parse</tt> isn't a set of number-formatting rules, but a <tt>RuleBasedCollator</tt>
219 * description which is used to define equivalences for lenient parsing. For more information
220 * on the syntax, see <tt>RuleBasedCollator</tt>. For more information on lenient parsing,
221 * see <tt>setLenientParse()</tt>.  <em>Note:</em> symbols that have syntactic meaning
222 * in collation rules, such as '&amp;', have no particular meaning when appearing outside
223 * of the <tt>lenient-parse</tt> rule set.</p>
224 *
225 * <p>The body of a rule set consists of an ordered, semicolon-delimited list of <em>rules.</em>
226 * Internally, every rule has a base value, a divisor, rule text, and zero, one, or two <em>substitutions.</em>
227 * These parameters are controlled by the description syntax, which consists of a <em>rule
228 * descriptor,</em> a colon, and a <em>rule body.</em></p>
229 *
230 * <p>A rule descriptor can take one of the following forms (text in <em>italics</em> is the
231 * name of a token):</p>
232 *
233 * <table border="0" width="100%">
234 *   <tr>
235 *     <td><em>bv</em>:</td>
236 *     <td><em>bv</em> specifies the rule's base value. <em>bv</em> is a decimal
237 *     number expressed using ASCII digits. <em>bv</em> may contain spaces, period, and commas,
238 *     which are ignored. The rule's divisor is the highest power of 10 less than or equal to
239 *     the base value.</td>
240 *   </tr>
241 *   <tr>
242 *     <td><em>bv</em>/<em>rad</em>:</td>
243 *     <td><em>bv</em> specifies the rule's base value. The rule's divisor is the
244 *     highest power of <em>rad</em> less than or equal to the base value.</td>
245 *   </tr>
246 *   <tr>
247 *     <td><em>bv</em>&gt;:</td>
248 *     <td><em>bv</em> specifies the rule's base value. To calculate the divisor,
249 *     let the radix be 10, and the exponent be the highest exponent of the radix that yields a
250 *     result less than or equal to the base value. Every &gt; character after the base value
251 *     decreases the exponent by 1. If the exponent is positive or 0, the divisor is the radix
252 *     raised to the power of the exponent; otherwise, the divisor is 1.</td>
253 *   </tr>
254 *   <tr>
255 *     <td><em>bv</em>/<em>rad</em>&gt;:</td>
256 *     <td><em>bv</em> specifies the rule's base value. To calculate the divisor,
257 *     let the radix be <em>rad</em>, and the exponent be the highest exponent of the radix that
258 *     yields a result less than or equal to the base value. Every &gt; character after the radix
259 *     decreases the exponent by 1. If the exponent is positive or 0, the divisor is the radix
260 *     raised to the power of the exponent; otherwise, the divisor is 1.</td>
261 *   </tr>
262 *   <tr>
263 *     <td>-x:</td>
264 *     <td>The rule is a negative-number rule.</td>
265 *   </tr>
266 *   <tr>
267 *     <td>x.x:</td>
268 *     <td>The rule is an <em>improper fraction rule.</em></td>
269 *   </tr>
270 *   <tr>
271 *     <td>0.x:</td>
272 *     <td>The rule is a <em>proper fraction rule.</em></td>
273 *   </tr>
274 *   <tr>
275 *     <td>x.0:</td>
276 *     <td>The rule is a <em>master rule.</em></td>
277 *   </tr>
278 *   <tr>
279 *     <td><em>nothing</em></td>
280 *     <td>If the rule's rule descriptor is left out, the base value is one plus the
281 *     preceding rule's base value (or zero if this is the first rule in the list) in a normal
282 *     rule set.&nbsp; In a fraction rule set, the base value is the same as the preceding rule's
283 *     base value.</td>
284 *   </tr>
285 * </table>
286 *
287 * <p>A rule set may be either a regular rule set or a <em>fraction rule set,</em> depending
288 * on whether it is used to format a number's integral part (or the whole number) or a
289 * number's fractional part. Using a rule set to format a rule's fractional part makes it a
290 * fraction rule set.</p>
291 *
292 * <p>Which rule is used to format a number is defined according to one of the following
293 * algorithms: If the rule set is a regular rule set, do the following:
294 *
295 * <ul>
296 *   <li>If the rule set includes a master rule (and the number was passed in as a <tt>double</tt>),
297 *     use the master rule.&nbsp; (If the number being formatted was passed in as a <tt>long</tt>,
298 *     the master rule is ignored.)</li>
299 *   <li>If the number is negative, use the negative-number rule.</li>
300 *   <li>If the number has a fractional part and is greater than 1, use the improper fraction
301 *     rule.</li>
302 *   <li>If the number has a fractional part and is between 0 and 1, use the proper fraction
303 *     rule.</li>
304 *   <li>Binary-search the rule list for the rule with the highest base value less than or equal
305 *     to the number. If that rule has two substitutions, its base value is not an even multiple
306 *     of its divisor, and the number <em>is</em> an even multiple of the rule's divisor, use the
307 *     rule that precedes it in the rule list. Otherwise, use the rule itself.</li>
308 * </ul>
309 *
310 * <p>If the rule set is a fraction rule set, do the following:
311 *
312 * <ul>
313 *   <li>Ignore negative-number and fraction rules.</li>
314 *   <li>For each rule in the list, multiply the number being formatted (which will always be
315 *     between 0 and 1) by the rule's base value. Keep track of the distance between the result
316 *     the nearest integer.</li>
317 *   <li>Use the rule that produced the result closest to zero in the above calculation. In the
318 *     event of a tie or a direct hit, use the first matching rule encountered. (The idea here is
319 *     to try each rule's base value as a possible denominator of a fraction. Whichever
320 *     denominator produces the fraction closest in value to the number being formatted wins.) If
321 *     the rule following the matching rule has the same base value, use it if the numerator of
322 *     the fraction is anything other than 1; if the numerator is 1, use the original matching
323 *     rule. (This is to allow singular and plural forms of the rule text without a lot of extra
324 *     hassle.)</li>
325 * </ul>
326 *
327 * <p>A rule's body consists of a string of characters terminated by a semicolon. The rule
328 * may include zero, one, or two <em>substitution tokens,</em> and a range of text in
329 * brackets. The brackets denote optional text (and may also include one or both
330 * substitutions). The exact meanings of the substitution tokens, and under what conditions
331 * optional text is omitted, depend on the syntax of the substitution token and the context.
332 * The rest of the text in a rule body is literal text that is output when the rule matches
333 * the number being formatted.</p>
334 *
335 * <p>A substitution token begins and ends with a <em>token character.</em> The token
336 * character and the context together specify a mathematical operation to be performed on the
337 * number being formatted. An optional <em>substitution descriptor </em>specifies how the
338 * value resulting from that operation is used to fill in the substitution. The position of
339 * the substitution token in the rule body specifies the location of the resultant text in
340 * the original rule text.</p>
341 *
342 * <p>The meanings of the substitution token characters are as follows:</p>
343 *
344 * <table border="0" width="100%">
345 *   <tr>
346 *     <td>&gt;&gt;</td>
347 *     <td>in normal rule</td>
348 *     <td>Divide the number by the rule's divisor and format the remainder</td>
349 *   </tr>
350 *   <tr>
351 *     <td></td>
352 *     <td>in negative-number rule</td>
353 *     <td>Find the absolute value of the number and format the result</td>
354 *   </tr>
355 *   <tr>
356 *     <td></td>
357 *     <td>in fraction or master rule</td>
358 *     <td>Isolate the number's fractional part and format it.</td>
359 *   </tr>
360 *   <tr>
361 *     <td></td>
362 *     <td>in rule in fraction rule set</td>
363 *     <td>Not allowed.</td>
364 *   </tr>
365 *   <tr>
366 *     <td>&gt;&gt;&gt;</td>
367 *     <td>in normal rule</td>
368 *     <td>Divide the number by the rule's divisor and format the remainder,
369 *       but bypass the normal rule-selection process and just use the
370 *       rule that precedes this one in this rule list.</td>
371 *   </tr>
372 *   <tr>
373 *     <td></td>
374 *     <td>in all other rules</td>
375 *     <td>Not allowed.</td>
376 *   </tr>
377 *   <tr>
378 *     <td>&lt;&lt;</td>
379 *     <td>in normal rule</td>
380 *     <td>Divide the number by the rule's divisor and format the quotient</td>
381 *   </tr>
382 *   <tr>
383 *     <td></td>
384 *     <td>in negative-number rule</td>
385 *     <td>Not allowed.</td>
386 *   </tr>
387 *   <tr>
388 *     <td></td>
389 *     <td>in fraction or master rule</td>
390 *     <td>Isolate the number's integral part and format it.</td>
391 *   </tr>
392 *   <tr>
393 *     <td></td>
394 *     <td>in rule in fraction rule set</td>
395 *     <td>Multiply the number by the rule's base value and format the result.</td>
396 *   </tr>
397 *   <tr>
398 *     <td>==</td>
399 *     <td>in all rule sets</td>
400 *     <td>Format the number unchanged</td>
401 *   </tr>
402 *   <tr>
403 *     <td>[]</td>
404 *     <td>in normal rule</td>
405 *     <td>Omit the optional text if the number is an even multiple of the rule's divisor</td>
406 *   </tr>
407 *   <tr>
408 *     <td></td>
409 *     <td>in negative-number rule</td>
410 *     <td>Not allowed.</td>
411 *   </tr>
412 *   <tr>
413 *     <td></td>
414 *     <td>in improper-fraction rule</td>
415 *     <td>Omit the optional text if the number is between 0 and 1 (same as specifying both an
416 *     x.x rule and a 0.x rule)</td>
417 *   </tr>
418 *   <tr>
419 *     <td></td>
420 *     <td>in master rule</td>
421 *     <td>Omit the optional text if the number is an integer (same as specifying both an x.x
422 *     rule and an x.0 rule)</td>
423 *   </tr>
424 *   <tr>
425 *     <td></td>
426 *     <td>in proper-fraction rule</td>
427 *     <td>Not allowed.</td>
428 *   </tr>
429 *   <tr>
430 *     <td></td>
431 *     <td>in rule in fraction rule set</td>
432 *     <td>Omit the optional text if multiplying the number by the rule's base value yields 1.</td>
433 *   </tr>
434 * </table>
435 *
436 * <p>The substitution descriptor (i.e., the text between the token characters) may take one
437 * of three forms:</p>
438 *
439 * <table border="0" width="100%">
440 *   <tr>
441 *     <td>a rule set name</td>
442 *     <td>Perform the mathematical operation on the number, and format the result using the
443 *     named rule set.</td>
444 *   </tr>
445 *   <tr>
446 *     <td>a DecimalFormat pattern</td>
447 *     <td>Perform the mathematical operation on the number, and format the result using a
448 *     DecimalFormat with the specified pattern.&nbsp; The pattern must begin with 0 or #.</td>
449 *   </tr>
450 *   <tr>
451 *     <td>nothing</td>
452 *     <td>Perform the mathematical operation on the number, and format the result using the rule
453 *     set containing the current rule, except:
454 *     <ul>
455 *       <li>You can't have an empty substitution descriptor with a == substitution.</li>
456 *       <li>If you omit the substitution descriptor in a &gt;&gt; substitution in a fraction rule,
457 *         format the result one digit at a time using the rule set containing the current rule.</li>
458 *       <li>If you omit the substitution descriptor in a &lt;&lt; substitution in a rule in a
459 *         fraction rule set, format the result using the default rule set for this formatter.</li>
460 *     </ul>
461 *     </td>
462 *   </tr>
463 * </table>
464 *
465 * <p>Whitespace is ignored between a rule set name and a rule set body, between a rule
466 * descriptor and a rule body, or between rules. If a rule body begins with an apostrophe,
467 * the apostrophe is ignored, but all text after it becomes significant (this is how you can
468 * have a rule's rule text begin with whitespace). There is no escape function: the semicolon
469 * is not allowed in rule set names or in rule text, and the colon is not allowed in rule set
470 * names. The characters beginning a substitution token are always treated as the beginning
471 * of a substitution token.</p>
472 *
473 * <p>See the resource data and the demo program for annotated examples of real rule sets
474 * using these features.</p>
475 *
476 * <p><em>User subclasses are not supported.</em> While clients may write
477 * subclasses, such code will not necessarily work and will not be
478 * guaranteed to work stably from release to release.
479 *
480 * <p><b>Localizations</b></p>
481 * <p>Constructors are available that allow the specification of localizations for the
482 * public rule sets (and also allow more control over what public rule sets are available).
483 * Localization data is represented as a textual description.  The description represents
484 * an array of arrays of string.  The first element is an array of the public rule set names,
485 * each of these must be one of the public rule set names that appear in the rules.  Only
486 * names in this array will be treated as public rule set names by the API.  Each subsequent
487 * element is an array of localizations of these names.  The first element of one of these
488 * subarrays is the locale name, and the remaining elements are localizations of the
489 * public rule set names, in the same order as they were listed in the first arrray.</p>
490 * <p>In the syntax, angle brackets '<', '>' are used to delimit the arrays, and comma ',' is used
491 * to separate elements of an array.  Whitespace is ignored, unless quoted.</p>
492 * <p>For example:<pre>
493 * < < %foo, %bar, %baz >,
494 *   < en, Foo, Bar, Baz >,
495 *   < fr, 'le Foo', 'le Bar', 'le Baz' >
496 *   < zh, \\u7532, \\u4e59, \\u4e19 > >
497 * </pre></p>
498 * @author Richard Gillam
499 * @see NumberFormat
500 * @see DecimalFormat
501 * @stable ICU 2.0
502 */
503class U_I18N_API RuleBasedNumberFormat : public NumberFormat {
504public:
505
506  //-----------------------------------------------------------------------
507  // constructors
508  //-----------------------------------------------------------------------
509
510    /**
511     * Creates a RuleBasedNumberFormat that behaves according to the description
512     * passed in.  The formatter uses the default locale.
513     * @param rules A description of the formatter's desired behavior.
514     * See the class documentation for a complete explanation of the description
515     * syntax.
516     * @param perror The parse error if an error was encountered.
517     * @param status The status indicating whether the constructor succeeded.
518     * @stable ICU 3.2
519     */
520    RuleBasedNumberFormat(const UnicodeString& rules, UParseError& perror, UErrorCode& status);
521
522    /**
523     * Creates a RuleBasedNumberFormat that behaves according to the description
524     * passed in.  The formatter uses the default locale.
525     * <p>
526     * The localizations data provides information about the public
527     * rule sets and their localized display names for different
528     * locales. The first element in the list is an array of the names
529     * of the public rule sets.  The first element in this array is
530     * the initial default ruleset.  The remaining elements in the
531     * list are arrays of localizations of the names of the public
532     * rule sets.  Each of these is one longer than the initial array,
533     * with the first String being the ULocale ID, and the remaining
534     * Strings being the localizations of the rule set names, in the
535     * same order as the initial array.  Arrays are NULL-terminated.
536     * @param rules A description of the formatter's desired behavior.
537     * See the class documentation for a complete explanation of the description
538     * syntax.
539     * @param localizations the localization information.
540     * names in the description.  These will be copied by the constructor.
541     * @param perror The parse error if an error was encountered.
542     * @param status The status indicating whether the constructor succeeded.
543     * @stable ICU 3.2
544     */
545    RuleBasedNumberFormat(const UnicodeString& rules, const UnicodeString& localizations,
546                        UParseError& perror, UErrorCode& status);
547
548  /**
549   * Creates a RuleBasedNumberFormat that behaves according to the rules
550   * passed in.  The formatter uses the specified locale to determine the
551   * characters to use when formatting numerals, and to define equivalences
552   * for lenient parsing.
553   * @param rules The formatter rules.
554   * See the class documentation for a complete explanation of the rule
555   * syntax.
556   * @param locale A locale that governs which characters are used for
557   * formatting values in numerals and which characters are equivalent in
558   * lenient parsing.
559   * @param perror The parse error if an error was encountered.
560   * @param status The status indicating whether the constructor succeeded.
561   * @stable ICU 2.0
562   */
563  RuleBasedNumberFormat(const UnicodeString& rules, const Locale& locale,
564                        UParseError& perror, UErrorCode& status);
565
566    /**
567     * Creates a RuleBasedNumberFormat that behaves according to the description
568     * passed in.  The formatter uses the default locale.
569     * <p>
570     * The localizations data provides information about the public
571     * rule sets and their localized display names for different
572     * locales. The first element in the list is an array of the names
573     * of the public rule sets.  The first element in this array is
574     * the initial default ruleset.  The remaining elements in the
575     * list are arrays of localizations of the names of the public
576     * rule sets.  Each of these is one longer than the initial array,
577     * with the first String being the ULocale ID, and the remaining
578     * Strings being the localizations of the rule set names, in the
579     * same order as the initial array.  Arrays are NULL-terminated.
580     * @param rules A description of the formatter's desired behavior.
581     * See the class documentation for a complete explanation of the description
582     * syntax.
583     * @param localizations a list of localizations for the rule set
584     * names in the description.  These will be copied by the constructor.
585     * @param locale A locale that governs which characters are used for
586     * formatting values in numerals and which characters are equivalent in
587     * lenient parsing.
588     * @param perror The parse error if an error was encountered.
589     * @param status The status indicating whether the constructor succeeded.
590     * @stable ICU 3.2
591     */
592    RuleBasedNumberFormat(const UnicodeString& rules, const UnicodeString& localizations,
593                        const Locale& locale, UParseError& perror, UErrorCode& status);
594
595  /**
596   * Creates a RuleBasedNumberFormat from a predefined ruleset.  The selector
597   * code choosed among three possible predefined formats: spellout, ordinal,
598   * and duration.
599   * @param tag A selector code specifying which kind of formatter to create for that
600   * locale.  There are four legal values: URBNF_SPELLOUT, which creates a formatter that
601   * spells out a value in words in the desired language, URBNF_ORDINAL, which attaches
602   * an ordinal suffix from the desired language to the end of a number (e.g. "123rd"),
603   * URBNF_DURATION, which formats a duration in seconds as hours, minutes, and seconds,
604   * and URBNF_NUMBERING_SYSTEM, which is used to invoke rules for alternate numbering
605   * systems such as the Hebrew numbering system, or for Roman Numerals, etc.
606   * @param locale The locale for the formatter.
607   * @param status The status indicating whether the constructor succeeded.
608   * @stable ICU 2.0
609   */
610  RuleBasedNumberFormat(URBNFRuleSetTag tag, const Locale& locale, UErrorCode& status);
611
612  //-----------------------------------------------------------------------
613  // boilerplate
614  //-----------------------------------------------------------------------
615
616  /**
617   * Copy constructor
618   * @param rhs    the object to be copied from.
619   * @stable ICU 2.6
620   */
621  RuleBasedNumberFormat(const RuleBasedNumberFormat& rhs);
622
623  /**
624   * Assignment operator
625   * @param rhs    the object to be copied from.
626   * @stable ICU 2.6
627   */
628  RuleBasedNumberFormat& operator=(const RuleBasedNumberFormat& rhs);
629
630  /**
631   * Release memory allocated for a RuleBasedNumberFormat when you are finished with it.
632   * @stable ICU 2.6
633   */
634  virtual ~RuleBasedNumberFormat();
635
636  /**
637   * Clone this object polymorphically.  The caller is responsible
638   * for deleting the result when done.
639   * @return  A copy of the object.
640   * @stable ICU 2.6
641   */
642  virtual Format* clone(void) const;
643
644  /**
645   * Return true if the given Format objects are semantically equal.
646   * Objects of different subclasses are considered unequal.
647   * @param other    the object to be compared with.
648   * @return        true if the given Format objects are semantically equal.
649   * @stable ICU 2.6
650   */
651  virtual UBool operator==(const Format& other) const;
652
653//-----------------------------------------------------------------------
654// public API functions
655//-----------------------------------------------------------------------
656
657  /**
658   * return the rules that were provided to the RuleBasedNumberFormat.
659   * @return the result String that was passed in
660   * @stable ICU 2.0
661   */
662  virtual UnicodeString getRules() const;
663
664  /**
665   * Return the number of public rule set names.
666   * @return the number of public rule set names.
667   * @stable ICU 2.0
668   */
669  virtual int32_t getNumberOfRuleSetNames() const;
670
671  /**
672   * Return the name of the index'th public ruleSet.  If index is not valid,
673   * the function returns null.
674   * @param index the index of the ruleset
675   * @return the name of the index'th public ruleSet.
676   * @stable ICU 2.0
677   */
678  virtual UnicodeString getRuleSetName(int32_t index) const;
679
680  /**
681   * Return the number of locales for which we have localized rule set display names.
682   * @return the number of locales for which we have localized rule set display names.
683   * @stable ICU 3.2
684   */
685  virtual int32_t getNumberOfRuleSetDisplayNameLocales(void) const;
686
687  /**
688   * Return the index'th display name locale.
689   * @param index the index of the locale
690   * @param status set to a failure code when this function fails
691   * @return the locale
692   * @see #getNumberOfRuleSetDisplayNameLocales
693   * @stable ICU 3.2
694   */
695  virtual Locale getRuleSetDisplayNameLocale(int32_t index, UErrorCode& status) const;
696
697    /**
698     * Return the rule set display names for the provided locale.  These are in the same order
699     * as those returned by getRuleSetName.  The locale is matched against the locales for
700     * which there is display name data, using normal fallback rules.  If no locale matches,
701     * the default display names are returned.  (These are the internal rule set names minus
702     * the leading '%'.)
703     * @param index the index of the rule set
704     * @param locale the locale (returned by getRuleSetDisplayNameLocales) for which the localized
705     * display name is desired
706     * @return the display name for the given index, which might be bogus if there is an error
707     * @see #getRuleSetName
708     * @stable ICU 3.2
709     */
710  virtual UnicodeString getRuleSetDisplayName(int32_t index,
711                          const Locale& locale = Locale::getDefault());
712
713    /**
714     * Return the rule set display name for the provided rule set and locale.
715     * The locale is matched against the locales for which there is display name data, using
716     * normal fallback rules.  If no locale matches, the default display name is returned.
717     * @return the display name for the rule set
718     * @stable ICU 3.2
719     * @see #getRuleSetDisplayName
720     */
721  virtual UnicodeString getRuleSetDisplayName(const UnicodeString& ruleSetName,
722                          const Locale& locale = Locale::getDefault());
723
724
725  using NumberFormat::format;
726
727  /**
728   * Formats the specified 32-bit number using the default ruleset.
729   * @param number The number to format.
730   * @param toAppendTo the string that will hold the (appended) result
731   * @param pos the fieldposition
732   * @return A textual representation of the number.
733   * @stable ICU 2.0
734   */
735  virtual UnicodeString& format(int32_t number,
736                                UnicodeString& toAppendTo,
737                                FieldPosition& pos) const;
738
739  /**
740   * Formats the specified 64-bit number using the default ruleset.
741   * @param number The number to format.
742   * @param toAppendTo the string that will hold the (appended) result
743   * @param pos the fieldposition
744   * @return A textual representation of the number.
745   * @stable ICU 2.1
746   */
747  virtual UnicodeString& format(int64_t number,
748                                UnicodeString& toAppendTo,
749                                FieldPosition& pos) const;
750  /**
751   * Formats the specified number using the default ruleset.
752   * @param number The number to format.
753   * @param toAppendTo the string that will hold the (appended) result
754   * @param pos the fieldposition
755   * @return A textual representation of the number.
756   * @stable ICU 2.0
757   */
758  virtual UnicodeString& format(double number,
759                                UnicodeString& toAppendTo,
760                                FieldPosition& pos) const;
761
762  /**
763   * Formats the specified number using the named ruleset.
764   * @param number The number to format.
765   * @param ruleSetName The name of the rule set to format the number with.
766   * This must be the name of a valid public rule set for this formatter.
767   * @param toAppendTo the string that will hold the (appended) result
768   * @param pos the fieldposition
769   * @param status the status
770   * @return A textual representation of the number.
771   * @stable ICU 2.0
772   */
773  virtual UnicodeString& format(int32_t number,
774                                const UnicodeString& ruleSetName,
775                                UnicodeString& toAppendTo,
776                                FieldPosition& pos,
777                                UErrorCode& status) const;
778  /**
779   * Formats the specified 64-bit number using the named ruleset.
780   * @param number The number to format.
781   * @param ruleSetName The name of the rule set to format the number with.
782   * This must be the name of a valid public rule set for this formatter.
783   * @param toAppendTo the string that will hold the (appended) result
784   * @param pos the fieldposition
785   * @param status the status
786   * @return A textual representation of the number.
787   * @stable ICU 2.1
788   */
789  virtual UnicodeString& format(int64_t number,
790                                const UnicodeString& ruleSetName,
791                                UnicodeString& toAppendTo,
792                                FieldPosition& pos,
793                                UErrorCode& status) const;
794  /**
795   * Formats the specified number using the named ruleset.
796   * @param number The number to format.
797   * @param ruleSetName The name of the rule set to format the number with.
798   * This must be the name of a valid public rule set for this formatter.
799   * @param toAppendTo the string that will hold the (appended) result
800   * @param pos the fieldposition
801   * @param status the status
802   * @return A textual representation of the number.
803   * @stable ICU 2.0
804   */
805  virtual UnicodeString& format(double number,
806                                const UnicodeString& ruleSetName,
807                                UnicodeString& toAppendTo,
808                                FieldPosition& pos,
809                                UErrorCode& status) const;
810
811  /**
812   * Formats the specified number using the default ruleset.
813   * @param obj The number to format.
814   * @param toAppendTo the string that will hold the (appended) result
815   * @param pos the fieldposition
816   * @param status the status
817   * @return A textual representation of the number.
818   * @stable ICU 2.0
819   */
820  virtual UnicodeString& format(const Formattable& obj,
821                                UnicodeString& toAppendTo,
822                                FieldPosition& pos,
823                                UErrorCode& status) const;
824  /**
825   * Redeclared Format method.
826   * @param obj    the object to be formatted.
827   * @param result Output param which will receive the formatted string.
828   * @param status Output param set to success/failure code
829   * @return       A reference to 'result'.
830   * @stable ICU 2.0
831   */
832  UnicodeString& format(const Formattable& obj,
833                        UnicodeString& result,
834                        UErrorCode& status) const;
835
836  /**
837   * Redeclared NumberFormat method.
838   * @param number    the double value to be formatted.
839   * @param output    Output param which will receive the formatted string.
840   * @return          A reference to 'output'.
841   * @stable ICU 2.0
842   */
843   UnicodeString& format(double number,
844                         UnicodeString& output) const;
845
846  /**
847   * Redeclared NumberFormat method.
848   * @param number    the long value to be formatted.
849   * @param output    Output param which will receive the formatted string.
850   * @return          A reference to 'output'.
851   * @stable ICU 2.0
852   */
853   UnicodeString& format(int32_t number,
854                         UnicodeString& output) const;
855
856  /**
857   * Parses the specfied string, beginning at the specified position, according
858   * to this formatter's rules.  This will match the string against all of the
859   * formatter's public rule sets and return the value corresponding to the longest
860   * parseable substring.  This function's behavior is affected by the lenient
861   * parse mode.
862   * @param text The string to parse
863   * @param result the result of the parse, either a double or a long.
864   * @param parsePosition On entry, contains the position of the first character
865   * in "text" to examine.  On exit, has been updated to contain the position
866   * of the first character in "text" that wasn't consumed by the parse.
867   * @see #setLenient
868   * @stable ICU 2.0
869   */
870  virtual void parse(const UnicodeString& text,
871                     Formattable& result,
872                     ParsePosition& parsePosition) const;
873
874
875  /**
876   * Redeclared Format method.
877   * @param text   The string to parse
878   * @param result the result of the parse, either a double or a long.
879   * @param status Output param set to failure code when a problem occurs.
880   * @stable ICU 2.0
881   */
882  virtual inline void parse(const UnicodeString& text,
883                      Formattable& result,
884                      UErrorCode& status) const;
885
886#if !UCONFIG_NO_COLLATION
887
888  /**
889   * Turns lenient parse mode on and off.
890   *
891   * When in lenient parse mode, the formatter uses a Collator for parsing the text.
892   * Only primary differences are treated as significant.  This means that case
893   * differences, accent differences, alternate spellings of the same letter
894   * (e.g., ae and a-umlaut in German), ignorable characters, etc. are ignored in
895   * matching the text.  In many cases, numerals will be accepted in place of words
896   * or phrases as well.
897   *
898   * For example, all of the following will correctly parse as 255 in English in
899   * lenient-parse mode:
900   * <br>"two hundred fifty-five"
901   * <br>"two hundred fifty five"
902   * <br>"TWO HUNDRED FIFTY-FIVE"
903   * <br>"twohundredfiftyfive"
904   * <br>"2 hundred fifty-5"
905   *
906   * The Collator used is determined by the locale that was
907   * passed to this object on construction.  The description passed to this object
908   * on construction may supply additional collation rules that are appended to the
909   * end of the default collator for the locale, enabling additional equivalences
910   * (such as adding more ignorable characters or permitting spelled-out version of
911   * symbols; see the demo program for examples).
912   *
913   * It's important to emphasize that even strict parsing is relatively lenient: it
914   * will accept some text that it won't produce as output.  In English, for example,
915   * it will correctly parse "two hundred zero" and "fifteen hundred".
916   *
917   * @param enabled If true, turns lenient-parse mode on; if false, turns it off.
918   * @see RuleBasedCollator
919   * @stable ICU 2.0
920   */
921  virtual void setLenient(UBool enabled);
922
923  /**
924   * Returns true if lenient-parse mode is turned on.  Lenient parsing is off
925   * by default.
926   * @return true if lenient-parse mode is turned on.
927   * @see #setLenient
928   * @stable ICU 2.0
929   */
930  virtual inline UBool isLenient(void) const;
931
932#endif
933
934  /**
935   * Override the default rule set to use.  If ruleSetName is null, reset
936   * to the initial default rule set.  If the rule set is not a public rule set name,
937   * U_ILLEGAL_ARGUMENT_ERROR is returned in status.
938   * @param ruleSetName the name of the rule set, or null to reset the initial default.
939   * @param status set to failure code when a problem occurs.
940   * @stable ICU 2.6
941   */
942  virtual void setDefaultRuleSet(const UnicodeString& ruleSetName, UErrorCode& status);
943
944  /**
945   * Return the name of the current default rule set.  If the current rule set is
946   * not public, returns a bogus (and empty) UnicodeString.
947   * @return the name of the current default rule set
948   * @stable ICU 3.0
949   */
950  virtual UnicodeString getDefaultRuleSetName() const;
951
952public:
953    /**
954     * ICU "poor man's RTTI", returns a UClassID for this class.
955     *
956     * @stable ICU 2.8
957     */
958    static UClassID U_EXPORT2 getStaticClassID(void);
959
960    /**
961     * ICU "poor man's RTTI", returns a UClassID for the actual class.
962     *
963     * @stable ICU 2.8
964     */
965    virtual UClassID getDynamicClassID(void) const;
966
967private:
968    RuleBasedNumberFormat(); // default constructor not implemented
969
970    // this will ref the localizations if they are not NULL
971    // caller must deref to get adoption
972    RuleBasedNumberFormat(const UnicodeString& description, LocalizationInfo* localizations,
973              const Locale& locale, UParseError& perror, UErrorCode& status);
974
975    void init(const UnicodeString& rules, LocalizationInfo* localizations, UParseError& perror, UErrorCode& status);
976    void dispose();
977    void stripWhitespace(UnicodeString& src);
978    void initDefaultRuleSet();
979    void format(double number, NFRuleSet& ruleSet);
980    NFRuleSet* findRuleSet(const UnicodeString& name, UErrorCode& status) const;
981
982    /* friend access */
983    friend class NFSubstitution;
984    friend class NFRule;
985    friend class FractionalPartSubstitution;
986
987    inline NFRuleSet * getDefaultRuleSet() const;
988    Collator * getCollator() const;
989    DecimalFormatSymbols * getDecimalFormatSymbols() const;
990
991private:
992    NFRuleSet **ruleSets;
993    NFRuleSet *defaultRuleSet;
994    Locale locale;
995    Collator* collator;
996    DecimalFormatSymbols* decimalFormatSymbols;
997    UBool lenient;
998    UnicodeString* lenientParseRules;
999    LocalizationInfo* localizations;
1000
1001    // Temporary workaround - when noParse is true, do noting in parse.
1002    // TODO: We need a real fix - see #6895/#6896
1003    UBool noParse;
1004};
1005
1006// ---------------
1007
1008inline UnicodeString&
1009RuleBasedNumberFormat::format(const Formattable& obj,
1010                              UnicodeString& result,
1011                              UErrorCode& status) const
1012{
1013    // Don't use Format:: - use immediate base class only,
1014    // in case immediate base modifies behavior later.
1015    // dlf - the above comment is bogus, if there were a reason to modify
1016    // it, it would be virtual, and there's no reason because it is
1017    // a one-line macro in NumberFormat anyway, just like this one.
1018    return NumberFormat::format(obj, result, status);
1019}
1020
1021inline UnicodeString&
1022RuleBasedNumberFormat::format(double number, UnicodeString& output) const {
1023    FieldPosition pos(0);
1024    return format(number, output, pos);
1025}
1026
1027inline UnicodeString&
1028RuleBasedNumberFormat::format(int32_t number, UnicodeString& output) const {
1029    FieldPosition pos(0);
1030    return format(number, output, pos);
1031}
1032
1033inline void
1034RuleBasedNumberFormat::parse(const UnicodeString& text, Formattable& result, UErrorCode& status) const
1035{
1036    NumberFormat::parse(text, result, status);
1037}
1038
1039#if !UCONFIG_NO_COLLATION
1040
1041inline UBool
1042RuleBasedNumberFormat::isLenient(void) const {
1043    return lenient;
1044}
1045
1046#endif
1047
1048inline NFRuleSet*
1049RuleBasedNumberFormat::getDefaultRuleSet() const {
1050    return defaultRuleSet;
1051}
1052
1053U_NAMESPACE_END
1054
1055/* U_HAVE_RBNF */
1056#endif
1057
1058/* RBNF_H */
1059#endif
1060