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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 "number_stringbuilder.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 
     41     AffixTag()
     42             : offset(0), state(STATE_BASE) {}
     43 
     44     AffixTag(int32_t offset)
     45             : offset(offset) {}
     46 
     47     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 NumberStringBuilder 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 NumberStringBuilder to mutate with the result.
    143      * @param position The index into the NumberStringBuilder to insert the string.
    144      * @param provider An object to generate locale symbols.
    145      */
    146     static int32_t unescape(const UnicodeString& affixPattern, NumberStringBuilder& output,
    147                             int32_t position, const SymbolProvider& provider, UErrorCode& status);
    148 
    149     /**
    150    * Sames as {@link #unescape}, but only calculates the code point count.  More efficient than {@link #unescape}
    151    * if you only need the length but not the string itself.
    152      *
    153      * @param affixPattern The original string to be unescaped.
    154      * @param provider An object to generate locale symbols.
    155      * @return The same return value as if you called {@link #unescape}.
    156      */
    157     static int32_t unescapedCodePointCount(const UnicodeString& affixPattern,
    158                                            const SymbolProvider& provider, UErrorCode& status);
    159 
    160     /**
    161      * Checks whether the given affix pattern contains at least one token of the given type, which is
    162      * one of the constants "TYPE_" in {@link AffixPatternUtils}.
    163      *
    164      * @param affixPattern The affix pattern to check.
    165      * @param type The token type.
    166      * @return true if the affix pattern contains the given token type; false otherwise.
    167      */
    168     static bool containsType(const UnicodeString& affixPattern, AffixPatternType type, UErrorCode& status);
    169 
    170     /**
    171      * Checks whether the specified affix pattern has any unquoted currency symbols ("").
    172      *
    173      * @param affixPattern The string to check for currency symbols.
    174      * @return true if the literal has at least one unquoted currency symbol; false otherwise.
    175      */
    176     static bool hasCurrencySymbols(const UnicodeString& affixPattern, UErrorCode& status);
    177 
    178     /**
    179      * Replaces all occurrences of tokens with the given type with the given replacement char.
    180      *
    181      * @param affixPattern The source affix pattern (does not get modified).
    182      * @param type The token type.
    183      * @param replacementChar The char to substitute in place of chars of the given token type.
    184      * @return A string containing the new affix pattern.
    185      */
    186     static UnicodeString replaceType(const UnicodeString& affixPattern, AffixPatternType type,
    187                                      char16_t replacementChar, UErrorCode& status);
    188 
    189     /**
    190      * Returns whether the given affix pattern contains only symbols and ignorables as defined by the
    191      * given ignorables set.
    192      */
    193     static bool containsOnlySymbolsAndIgnorables(const UnicodeString& affixPattern,
    194                                                  const UnicodeSet& ignorables, UErrorCode& status);
    195 
    196     /**
    197      * Iterates over the affix pattern, calling the TokenConsumer for each token.
    198      */
    199     static void iterateWithConsumer(const UnicodeString& affixPattern, TokenConsumer& consumer,
    200                                     UErrorCode& status);
    201 
    202     /**
    203      * Returns the next token from the affix pattern.
    204      *
    205      * @param tag A bitmask used for keeping track of state from token to token. The initial value
    206      *     should be 0L.
    207      * @param patternString The affix pattern.
    208      * @return The bitmask tag to pass to the next call of this method to retrieve the following token
    209      *     (never negative), or -1 if there were no more tokens in the affix pattern.
    210      * @see #hasNext
    211      */
    212     static AffixTag nextToken(AffixTag tag, const UnicodeString& patternString, UErrorCode& status);
    213 
    214     /**
    215      * Returns whether the affix pattern string has any more tokens to be retrieved from a call to
    216      * {@link #nextToken}.
    217      *
    218      * @param tag The bitmask tag of the previous token, as returned by {@link #nextToken}.
    219      * @param string The affix pattern.
    220      * @return true if there are more tokens to consume; false otherwise.
    221      */
    222     static bool hasNext(const AffixTag& tag, const UnicodeString& string);
    223 
    224   private:
    225     /**
    226      * Encodes the given values into a tag struct.
    227      * The order of the arguments is consistent with Java, but the order of the stored
    228      * fields is not necessarily the same.
    229      */
    230     static inline AffixTag makeTag(int32_t offset, AffixPatternType type, AffixPatternState state,
    231                                    UChar32 cp) {
    232         return {offset, cp, state, type};
    233     }
    234 };
    235 
    236 } // namespace impl
    237 } // namespace number
    238 U_NAMESPACE_END
    239 
    240 
    241 #endif //__NUMBER_AFFIXUTILS_H__
    242 
    243 #endif /* #if !UCONFIG_NO_FORMATTING */
    244