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1 // © 2017 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 
4 #include "unicode/utypes.h"
5 
6 #if !UCONFIG_NO_FORMATTING
7 #ifndef __NUMBER_AFFIXUTILS_H__
8 #define __NUMBER_AFFIXUTILS_H__
9 
10 #include <cstdint>
11 #include "number_types.h"
12 #include "unicode/stringpiece.h"
13 #include "unicode/unistr.h"
14 #include "formatted_string_builder.h"
15 #include "unicode/uniset.h"
16 
17 U_NAMESPACE_BEGIN namespace number {
18 namespace impl {
19 
20 enum AffixPatternState {
21     STATE_BASE = 0,
22     STATE_FIRST_QUOTE = 1,
23     STATE_INSIDE_QUOTE = 2,
24     STATE_AFTER_QUOTE = 3,
25     STATE_FIRST_CURR = 4,
26     STATE_SECOND_CURR = 5,
27     STATE_THIRD_CURR = 6,
28     STATE_FOURTH_CURR = 7,
29     STATE_FIFTH_CURR = 8,
30     STATE_OVERFLOW_CURR = 9
31 };
32 
33 // enum AffixPatternType defined in internals.h
34 
35 struct AffixTag {
36     int32_t offset;
37     UChar32 codePoint;
38     AffixPatternState state;
39     AffixPatternType type;
40 
AffixTagAffixTag41     AffixTag()
42             : offset(0), state(STATE_BASE) {}
43 
AffixTagAffixTag44     AffixTag(int32_t offset)
45             : offset(offset) {}
46 
AffixTagAffixTag47     AffixTag(int32_t offset, UChar32 codePoint, AffixPatternState state, AffixPatternType type)
48             : offset(offset), codePoint(codePoint), state(state), type(type) {}
49 };
50 
51 class TokenConsumer {
52   public:
53     virtual ~TokenConsumer();
54 
55     virtual void consumeToken(AffixPatternType type, UChar32 cp, UErrorCode& status) = 0;
56 };
57 
58 // Exported as U_I18N_API because it is a base class for other exported types
59 class U_I18N_API SymbolProvider {
60   public:
61     virtual ~SymbolProvider();
62 
63     // TODO: Could this be more efficient if it returned by reference?
64     virtual UnicodeString getSymbol(AffixPatternType type) const = 0;
65 };
66 
67 /**
68  * Performs manipulations on affix patterns: the prefix and suffix strings associated with a decimal
69  * format pattern. For example:
70  *
71  * <table>
72  * <tr><th>Affix Pattern</th><th>Example Unescaped (Formatted) String</th></tr>
73  * <tr><td>abc</td><td>abc</td></tr>
74  * <tr><td>ab-</td><td>ab−</td></tr>
75  * <tr><td>ab'-'</td><td>ab-</td></tr>
76  * <tr><td>ab''</td><td>ab'</td></tr>
77  * </table>
78  *
79  * To manually iterate over tokens in a literal string, use the following pattern, which is designed
80  * to be efficient.
81  *
82  * <pre>
83  * long tag = 0L;
84  * while (AffixPatternUtils.hasNext(tag, patternString)) {
85  *   tag = AffixPatternUtils.nextToken(tag, patternString);
86  *   int typeOrCp = AffixPatternUtils.getTypeOrCp(tag);
87  *   switch (typeOrCp) {
88  *     case AffixPatternUtils.TYPE_MINUS_SIGN:
89  *       // Current token is a minus sign.
90  *       break;
91  *     case AffixPatternUtils.TYPE_PLUS_SIGN:
92  *       // Current token is a plus sign.
93  *       break;
94  *     case AffixPatternUtils.TYPE_PERCENT:
95  *       // Current token is a percent sign.
96  *       break;
97  *     // ... other types ...
98  *     default:
99  *       // Current token is an arbitrary code point.
100  *       // The variable typeOrCp is the code point.
101  *       break;
102  *   }
103  * }
104  * </pre>
105  */
106 class U_I18N_API AffixUtils {
107 
108   public:
109 
110     /**
111      * Estimates the number of code points present in an unescaped version of the affix pattern string
112      * (one that would be returned by {@link #unescape}), assuming that all interpolated symbols
113      * consume one code point and that currencies consume as many code points as their symbol width.
114      * Used for computing padding width.
115      *
116      * @param patternString The original string whose width will be estimated.
117      * @return The length of the unescaped string.
118      */
119     static int32_t estimateLength(const UnicodeString& patternString, UErrorCode& status);
120 
121     /**
122      * Takes a string and escapes (quotes) characters that have special meaning in the affix pattern
123      * syntax. This function does not reverse-lookup symbols.
124      *
125      * <p>Example input: "-$x"; example output: "'-'$x"
126      *
127      * @param input The string to be escaped.
128      * @return The resulting UnicodeString.
129      */
130     static UnicodeString escape(const UnicodeString& input);
131 
132     static Field getFieldForType(AffixPatternType type);
133 
134     /**
135      * Executes the unescape state machine. Replaces the unquoted characters "-", "+", "%", "‰", and
136      * "¤" with the corresponding symbols provided by the {@link SymbolProvider}, and inserts the
137      * result into the FormattedStringBuilder at the requested location.
138      *
139      * <p>Example input: "'-'¤x"; example output: "-$x"
140      *
141      * @param affixPattern The original string to be unescaped.
142      * @param output The FormattedStringBuilder to mutate with the result.
143      * @param position The index into the FormattedStringBuilder to insert the string.
144      * @param provider An object to generate locale symbols.
145      */
146     static int32_t unescape(const UnicodeString& affixPattern, FormattedStringBuilder& output,
147                             int32_t position, const SymbolProvider& provider, Field field,
148                             UErrorCode& status);
149 
150     /**
151    * Sames as {@link #unescape}, but only calculates the code point count.  More efficient than {@link #unescape}
152    * if you only need the length but not the string itself.
153      *
154      * @param affixPattern The original string to be unescaped.
155      * @param provider An object to generate locale symbols.
156      * @return The same return value as if you called {@link #unescape}.
157      */
158     static int32_t unescapedCodePointCount(const UnicodeString& affixPattern,
159                                            const SymbolProvider& provider, UErrorCode& status);
160 
161     /**
162      * Checks whether the given affix pattern contains at least one token of the given type, which is
163      * one of the constants "TYPE_" in {@link AffixPatternUtils}.
164      *
165      * @param affixPattern The affix pattern to check.
166      * @param type The token type.
167      * @return true if the affix pattern contains the given token type; false otherwise.
168      */
169     static bool containsType(const UnicodeString& affixPattern, AffixPatternType type, UErrorCode& status);
170 
171     /**
172      * Checks whether the specified affix pattern has any unquoted currency symbols ("¤").
173      *
174      * @param affixPattern The string to check for currency symbols.
175      * @return true if the literal has at least one unquoted currency symbol; false otherwise.
176      */
177     static bool hasCurrencySymbols(const UnicodeString& affixPattern, UErrorCode& status);
178 
179     /**
180      * Replaces all occurrences of tokens with the given type with the given replacement char.
181      *
182      * @param affixPattern The source affix pattern (does not get modified).
183      * @param type The token type.
184      * @param replacementChar The char to substitute in place of chars of the given token type.
185      * @return A string containing the new affix pattern.
186      */
187     static UnicodeString replaceType(const UnicodeString& affixPattern, AffixPatternType type,
188                                      char16_t replacementChar, UErrorCode& status);
189 
190     /**
191      * Returns whether the given affix pattern contains only symbols and ignorables as defined by the
192      * given ignorables set.
193      */
194     static bool containsOnlySymbolsAndIgnorables(const UnicodeString& affixPattern,
195                                                  const UnicodeSet& ignorables, UErrorCode& status);
196 
197     /**
198      * Iterates over the affix pattern, calling the TokenConsumer for each token.
199      */
200     static void iterateWithConsumer(const UnicodeString& affixPattern, TokenConsumer& consumer,
201                                     UErrorCode& status);
202 
203     /**
204      * Returns the next token from the affix pattern.
205      *
206      * @param tag A bitmask used for keeping track of state from token to token. The initial value
207      *     should be 0L.
208      * @param patternString The affix pattern.
209      * @return The bitmask tag to pass to the next call of this method to retrieve the following token
210      *     (never negative), or -1 if there were no more tokens in the affix pattern.
211      * @see #hasNext
212      */
213     static AffixTag nextToken(AffixTag tag, const UnicodeString& patternString, UErrorCode& status);
214 
215     /**
216      * Returns whether the affix pattern string has any more tokens to be retrieved from a call to
217      * {@link #nextToken}.
218      *
219      * @param tag The bitmask tag of the previous token, as returned by {@link #nextToken}.
220      * @param string The affix pattern.
221      * @return true if there are more tokens to consume; false otherwise.
222      */
223     static bool hasNext(const AffixTag& tag, const UnicodeString& string);
224 
225   private:
226     /**
227      * Encodes the given values into a tag struct.
228      * The order of the arguments is consistent with Java, but the order of the stored
229      * fields is not necessarily the same.
230      */
makeTag(int32_t offset,AffixPatternType type,AffixPatternState state,UChar32 cp)231     static inline AffixTag makeTag(int32_t offset, AffixPatternType type, AffixPatternState state,
232                                    UChar32 cp) {
233         return {offset, cp, state, type};
234     }
235 };
236 
237 } // namespace impl
238 } // namespace number
239 U_NAMESPACE_END
240 
241 
242 #endif //__NUMBER_AFFIXUTILS_H__
243 
244 #endif /* #if !UCONFIG_NO_FORMATTING */
245