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Diffstat (limited to 'intl/icu/source/i18n/number_affixutils.h')
-rw-r--r-- | intl/icu/source/i18n/number_affixutils.h | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/number_affixutils.h b/intl/icu/source/i18n/number_affixutils.h new file mode 100644 index 0000000000..5cfde61ffd --- /dev/null +++ b/intl/icu/source/i18n/number_affixutils.h @@ -0,0 +1,244 @@ +// © 2017 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html + +#include "unicode/utypes.h" + +#if !UCONFIG_NO_FORMATTING +#ifndef __NUMBER_AFFIXUTILS_H__ +#define __NUMBER_AFFIXUTILS_H__ + +#include <cstdint> +#include "number_types.h" +#include "unicode/stringpiece.h" +#include "unicode/unistr.h" +#include "formatted_string_builder.h" +#include "unicode/uniset.h" + +U_NAMESPACE_BEGIN namespace number { +namespace impl { + +enum AffixPatternState { + STATE_BASE = 0, + STATE_FIRST_QUOTE = 1, + STATE_INSIDE_QUOTE = 2, + STATE_AFTER_QUOTE = 3, + STATE_FIRST_CURR = 4, + STATE_SECOND_CURR = 5, + STATE_THIRD_CURR = 6, + STATE_FOURTH_CURR = 7, + STATE_FIFTH_CURR = 8, + STATE_OVERFLOW_CURR = 9 +}; + +// enum AffixPatternType defined in internals.h + +struct AffixTag { + int32_t offset; + UChar32 codePoint; + AffixPatternState state; + AffixPatternType type; + + AffixTag() + : offset(0), state(STATE_BASE) {} + + AffixTag(int32_t offset) + : offset(offset) {} + + AffixTag(int32_t offset, UChar32 codePoint, AffixPatternState state, AffixPatternType type) + : offset(offset), codePoint(codePoint), state(state), type(type) {} +}; + +class TokenConsumer { + public: + virtual ~TokenConsumer(); + + virtual void consumeToken(AffixPatternType type, UChar32 cp, UErrorCode& status) = 0; +}; + +// Exported as U_I18N_API because it is a base class for other exported types +class U_I18N_API SymbolProvider { + public: + virtual ~SymbolProvider(); + + // TODO: Could this be more efficient if it returned by reference? + virtual UnicodeString getSymbol(AffixPatternType type) const = 0; +}; + +/** + * Performs manipulations on affix patterns: the prefix and suffix strings associated with a decimal + * format pattern. For example: + * + * <table> + * <tr><th>Affix Pattern</th><th>Example Unescaped (Formatted) String</th></tr> + * <tr><td>abc</td><td>abc</td></tr> + * <tr><td>ab-</td><td>ab−</td></tr> + * <tr><td>ab'-'</td><td>ab-</td></tr> + * <tr><td>ab''</td><td>ab'</td></tr> + * </table> + * + * To manually iterate over tokens in a literal string, use the following pattern, which is designed + * to be efficient. + * + * <pre> + * long tag = 0L; + * while (AffixPatternUtils.hasNext(tag, patternString)) { + * tag = AffixPatternUtils.nextToken(tag, patternString); + * int typeOrCp = AffixPatternUtils.getTypeOrCp(tag); + * switch (typeOrCp) { + * case AffixPatternUtils.TYPE_MINUS_SIGN: + * // Current token is a minus sign. + * break; + * case AffixPatternUtils.TYPE_PLUS_SIGN: + * // Current token is a plus sign. + * break; + * case AffixPatternUtils.TYPE_PERCENT: + * // Current token is a percent sign. + * break; + * // ... other types ... + * default: + * // Current token is an arbitrary code point. + * // The variable typeOrCp is the code point. + * break; + * } + * } + * </pre> + */ +class U_I18N_API AffixUtils { + + public: + + /** + * Estimates the number of code points present in an unescaped version of the affix pattern string + * (one that would be returned by {@link #unescape}), assuming that all interpolated symbols + * consume one code point and that currencies consume as many code points as their symbol width. + * Used for computing padding width. + * + * @param patternString The original string whose width will be estimated. + * @return The length of the unescaped string. + */ + static int32_t estimateLength(const UnicodeString& patternString, UErrorCode& status); + + /** + * Takes a string and escapes (quotes) characters that have special meaning in the affix pattern + * syntax. This function does not reverse-lookup symbols. + * + * <p>Example input: "-$x"; example output: "'-'$x" + * + * @param input The string to be escaped. + * @return The resulting UnicodeString. + */ + static UnicodeString escape(const UnicodeString& input); + + static Field getFieldForType(AffixPatternType type); + + /** + * Executes the unescape state machine. Replaces the unquoted characters "-", "+", "%", "‰", and + * "¤" with the corresponding symbols provided by the {@link SymbolProvider}, and inserts the + * result into the FormattedStringBuilder at the requested location. + * + * <p>Example input: "'-'¤x"; example output: "-$x" + * + * @param affixPattern The original string to be unescaped. + * @param output The FormattedStringBuilder to mutate with the result. + * @param position The index into the FormattedStringBuilder to insert the string. + * @param provider An object to generate locale symbols. + */ + static int32_t unescape(const UnicodeString& affixPattern, FormattedStringBuilder& output, + int32_t position, const SymbolProvider& provider, Field field, + UErrorCode& status); + + /** + * Sames as {@link #unescape}, but only calculates the code point count. More efficient than {@link #unescape} + * if you only need the length but not the string itself. + * + * @param affixPattern The original string to be unescaped. + * @param provider An object to generate locale symbols. + * @return The same return value as if you called {@link #unescape}. + */ + static int32_t unescapedCodePointCount(const UnicodeString& affixPattern, + const SymbolProvider& provider, UErrorCode& status); + + /** + * Checks whether the given affix pattern contains at least one token of the given type, which is + * one of the constants "TYPE_" in {@link AffixPatternUtils}. + * + * @param affixPattern The affix pattern to check. + * @param type The token type. + * @return true if the affix pattern contains the given token type; false otherwise. + */ + static bool containsType(const UnicodeString& affixPattern, AffixPatternType type, UErrorCode& status); + + /** + * Checks whether the specified affix pattern has any unquoted currency symbols ("¤"). + * + * @param affixPattern The string to check for currency symbols. + * @return true if the literal has at least one unquoted currency symbol; false otherwise. + */ + static bool hasCurrencySymbols(const UnicodeString& affixPattern, UErrorCode& status); + + /** + * Replaces all occurrences of tokens with the given type with the given replacement char. + * + * @param affixPattern The source affix pattern (does not get modified). + * @param type The token type. + * @param replacementChar The char to substitute in place of chars of the given token type. + * @return A string containing the new affix pattern. + */ + static UnicodeString replaceType(const UnicodeString& affixPattern, AffixPatternType type, + char16_t replacementChar, UErrorCode& status); + + /** + * Returns whether the given affix pattern contains only symbols and ignorables as defined by the + * given ignorables set. + */ + static bool containsOnlySymbolsAndIgnorables(const UnicodeString& affixPattern, + const UnicodeSet& ignorables, UErrorCode& status); + + /** + * Iterates over the affix pattern, calling the TokenConsumer for each token. + */ + static void iterateWithConsumer(const UnicodeString& affixPattern, TokenConsumer& consumer, + UErrorCode& status); + + /** + * Returns the next token from the affix pattern. + * + * @param tag A bitmask used for keeping track of state from token to token. The initial value + * should be 0L. + * @param patternString The affix pattern. + * @return The bitmask tag to pass to the next call of this method to retrieve the following token + * (never negative), or -1 if there were no more tokens in the affix pattern. + * @see #hasNext + */ + static AffixTag nextToken(AffixTag tag, const UnicodeString& patternString, UErrorCode& status); + + /** + * Returns whether the affix pattern string has any more tokens to be retrieved from a call to + * {@link #nextToken}. + * + * @param tag The bitmask tag of the previous token, as returned by {@link #nextToken}. + * @param string The affix pattern. + * @return true if there are more tokens to consume; false otherwise. + */ + static bool hasNext(const AffixTag& tag, const UnicodeString& string); + + private: + /** + * Encodes the given values into a tag struct. + * The order of the arguments is consistent with Java, but the order of the stored + * fields is not necessarily the same. + */ + static inline AffixTag makeTag(int32_t offset, AffixPatternType type, AffixPatternState state, + UChar32 cp) { + return {offset, cp, state, type}; + } +}; + +} // namespace impl +} // namespace number +U_NAMESPACE_END + + +#endif //__NUMBER_AFFIXUTILS_H__ + +#endif /* #if !UCONFIG_NO_FORMATTING */ |