Victor Chang | d8aa9d5 | 2021-01-05 23:49:57 +0000 | [diff] [blame] | 1 | // © 2020 and later: Unicode, Inc. and others. |
| 2 | // License & terms of use: http://www.unicode.org/copyright.html |
| 3 | |
| 4 | #ifndef __MEASUNIT_IMPL_H__ |
| 5 | #define __MEASUNIT_IMPL_H__ |
| 6 | |
| 7 | #include "unicode/utypes.h" |
| 8 | |
| 9 | #if !UCONFIG_NO_FORMATTING |
| 10 | |
| 11 | #include "unicode/measunit.h" |
| 12 | #include "cmemory.h" |
| 13 | #include "charstr.h" |
| 14 | |
| 15 | U_NAMESPACE_BEGIN |
| 16 | |
| 17 | |
| 18 | static const char16_t kDefaultCurrency[] = u"XXX"; |
| 19 | static const char kDefaultCurrency8[] = "XXX"; |
| 20 | |
| 21 | |
| 22 | /** |
| 23 | * A struct representing a single unit (optional SI prefix and dimensionality). |
| 24 | */ |
Victor Chang | ce4bf3c | 2021-01-19 16:34:24 +0000 | [diff] [blame^] | 25 | struct U_I18N_API SingleUnitImpl : public UMemory { |
Victor Chang | d8aa9d5 | 2021-01-05 23:49:57 +0000 | [diff] [blame] | 26 | /** |
| 27 | * Gets a single unit from the MeasureUnit. If there are multiple single units, sets an error |
| 28 | * code and returns the base dimensionless unit. Parses if necessary. |
| 29 | */ |
| 30 | static SingleUnitImpl forMeasureUnit(const MeasureUnit& measureUnit, UErrorCode& status); |
| 31 | |
| 32 | /** Transform this SingleUnitImpl into a MeasureUnit, simplifying if possible. */ |
| 33 | MeasureUnit build(UErrorCode& status) const; |
| 34 | |
| 35 | /** |
Victor Chang | ce4bf3c | 2021-01-19 16:34:24 +0000 | [diff] [blame^] | 36 | * Returns the "simple unit ID", without SI or dimensionality prefix: this |
| 37 | * instance may represent a square-kilometer, but only "meter" will be |
| 38 | * returned. |
| 39 | * |
| 40 | * The returned pointer points at memory that exists for the duration of the |
| 41 | * program's running. |
| 42 | */ |
| 43 | const char *getSimpleUnitID() const; |
| 44 | |
| 45 | /** |
Victor Chang | d8aa9d5 | 2021-01-05 23:49:57 +0000 | [diff] [blame] | 46 | * Compare this SingleUnitImpl to another SingleUnitImpl for the sake of |
| 47 | * sorting and coalescing. |
| 48 | * |
| 49 | * Takes the sign of dimensionality into account, but not the absolute |
| 50 | * value: per-meter is not considered the same as meter, but meter is |
| 51 | * considered the same as square-meter. |
| 52 | * |
| 53 | * The dimensionless unit generally does not get compared, but if it did, it |
| 54 | * would sort before other units by virtue of index being < 0 and |
| 55 | * dimensionality not being negative. |
| 56 | */ |
| 57 | int32_t compareTo(const SingleUnitImpl& other) const { |
| 58 | if (dimensionality < 0 && other.dimensionality > 0) { |
| 59 | // Positive dimensions first |
| 60 | return 1; |
| 61 | } |
| 62 | if (dimensionality > 0 && other.dimensionality < 0) { |
| 63 | return -1; |
| 64 | } |
| 65 | if (index < other.index) { |
| 66 | return -1; |
| 67 | } |
| 68 | if (index > other.index) { |
| 69 | return 1; |
| 70 | } |
| 71 | if (siPrefix < other.siPrefix) { |
| 72 | return -1; |
| 73 | } |
| 74 | if (siPrefix > other.siPrefix) { |
| 75 | return 1; |
| 76 | } |
| 77 | return 0; |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Return whether this SingleUnitImpl is compatible with another for the purpose of coalescing. |
| 82 | * |
| 83 | * Units with the same base unit and SI prefix should match, except that they must also have |
| 84 | * the same dimensionality sign, such that we don't merge numerator and denominator. |
| 85 | */ |
| 86 | bool isCompatibleWith(const SingleUnitImpl& other) const { |
| 87 | return (compareTo(other) == 0); |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Returns true if this unit is the "dimensionless base unit", as produced |
| 92 | * by the MeasureUnit() default constructor. (This does not include the |
| 93 | * likes of concentrations or angles.) |
| 94 | */ |
| 95 | bool isDimensionless() const { |
| 96 | return index == -1; |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * Simple unit index, unique for every simple unit, -1 for the dimensionless |
| 101 | * unit. This is an index into a string list in measunit_extra.cpp. |
| 102 | * |
| 103 | * The default value is -1, meaning the dimensionless unit: |
| 104 | * isDimensionless() will return true, until index is changed. |
| 105 | */ |
| 106 | int32_t index = -1; |
| 107 | |
| 108 | /** |
| 109 | * SI prefix. |
| 110 | * |
| 111 | * This is ignored for the dimensionless unit. |
| 112 | */ |
| 113 | UMeasureSIPrefix siPrefix = UMEASURE_SI_PREFIX_ONE; |
| 114 | |
| 115 | /** |
| 116 | * Dimensionality. |
| 117 | * |
| 118 | * This is meaningless for the dimensionless unit. |
| 119 | */ |
| 120 | int32_t dimensionality = 1; |
| 121 | }; |
| 122 | |
Victor Chang | ce4bf3c | 2021-01-19 16:34:24 +0000 | [diff] [blame^] | 123 | // Export explicit template instantiations of MaybeStackArray, MemoryPool and |
| 124 | // MaybeStackVector. This is required when building DLLs for Windows. (See |
| 125 | // datefmt.h, collationiterator.h, erarules.h and others for similar examples.) |
| 126 | #if U_PF_WINDOWS <= U_PLATFORM && U_PLATFORM <= U_PF_CYGWIN |
| 127 | template class U_I18N_API MaybeStackArray<SingleUnitImpl*, 8>; |
| 128 | template class U_I18N_API MemoryPool<SingleUnitImpl, 8>; |
| 129 | template class U_I18N_API MaybeStackVector<SingleUnitImpl, 8>; |
| 130 | #endif |
Victor Chang | d8aa9d5 | 2021-01-05 23:49:57 +0000 | [diff] [blame] | 131 | |
| 132 | /** |
| 133 | * Internal representation of measurement units. Capable of representing all complexities of units, |
| 134 | * including mixed and compound units. |
| 135 | */ |
Victor Chang | ce4bf3c | 2021-01-19 16:34:24 +0000 | [diff] [blame^] | 136 | struct U_I18N_API MeasureUnitImpl : public UMemory { |
| 137 | MeasureUnitImpl() = default; |
| 138 | MeasureUnitImpl(MeasureUnitImpl &&other) = default; |
| 139 | MeasureUnitImpl(const MeasureUnitImpl &other, UErrorCode &status); |
| 140 | MeasureUnitImpl(const SingleUnitImpl &singleUnit, UErrorCode &status); |
| 141 | |
| 142 | MeasureUnitImpl &operator=(MeasureUnitImpl &&other) noexcept = default; |
| 143 | |
Victor Chang | d8aa9d5 | 2021-01-05 23:49:57 +0000 | [diff] [blame] | 144 | /** Extract the MeasureUnitImpl from a MeasureUnit. */ |
| 145 | static inline const MeasureUnitImpl* get(const MeasureUnit& measureUnit) { |
| 146 | return measureUnit.fImpl; |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * Parse a unit identifier into a MeasureUnitImpl. |
| 151 | * |
| 152 | * @param identifier The unit identifier string. |
| 153 | * @param status Set if the identifier string is not valid. |
| 154 | * @return A newly parsed value object. Behaviour of this unit is |
| 155 | * unspecified if an error is returned via status. |
| 156 | */ |
| 157 | static MeasureUnitImpl forIdentifier(StringPiece identifier, UErrorCode& status); |
| 158 | |
| 159 | /** |
| 160 | * Extract the MeasureUnitImpl from a MeasureUnit, or parse if it is not present. |
| 161 | * |
| 162 | * @param measureUnit The source MeasureUnit. |
| 163 | * @param memory A place to write the new MeasureUnitImpl if parsing is required. |
| 164 | * @param status Set if an error occurs. |
| 165 | * @return A reference to either measureUnit.fImpl or memory. |
| 166 | */ |
| 167 | static const MeasureUnitImpl& forMeasureUnit( |
| 168 | const MeasureUnit& measureUnit, MeasureUnitImpl& memory, UErrorCode& status); |
| 169 | |
| 170 | /** |
| 171 | * Extract the MeasureUnitImpl from a MeasureUnit, or parse if it is not present. |
| 172 | * |
| 173 | * @param measureUnit The source MeasureUnit. |
| 174 | * @param status Set if an error occurs. |
| 175 | * @return A value object, either newly parsed or copied from measureUnit. |
| 176 | */ |
| 177 | static MeasureUnitImpl forMeasureUnitMaybeCopy( |
| 178 | const MeasureUnit& measureUnit, UErrorCode& status); |
| 179 | |
| 180 | /** |
| 181 | * Used for currency units. |
| 182 | */ |
| 183 | static inline MeasureUnitImpl forCurrencyCode(StringPiece currencyCode) { |
| 184 | MeasureUnitImpl result; |
| 185 | UErrorCode localStatus = U_ZERO_ERROR; |
| 186 | result.identifier.append(currencyCode, localStatus); |
| 187 | // localStatus is not expected to fail since currencyCode should be 3 chars long |
| 188 | return result; |
| 189 | } |
| 190 | |
| 191 | /** Transform this MeasureUnitImpl into a MeasureUnit, simplifying if possible. */ |
| 192 | MeasureUnit build(UErrorCode& status) &&; |
| 193 | |
| 194 | /** |
| 195 | * Create a copy of this MeasureUnitImpl. Don't use copy constructor to make this explicit. |
| 196 | */ |
Victor Chang | ce4bf3c | 2021-01-19 16:34:24 +0000 | [diff] [blame^] | 197 | MeasureUnitImpl copy(UErrorCode& status) const; |
| 198 | |
| 199 | /** |
| 200 | * Extracts the list of all the individual units inside the `MeasureUnitImpl`. |
| 201 | * For example: |
| 202 | * - if the `MeasureUnitImpl` is `foot-per-hour` |
| 203 | * it will return a list of 1 {`foot-per-hour`} |
| 204 | * - if the `MeasureUnitImpl` is `foot-and-inch` |
| 205 | * it will return a list of 2 { `foot`, `inch`} |
| 206 | */ |
| 207 | MaybeStackVector<MeasureUnitImpl> extractIndividualUnits(UErrorCode &status) const; |
Victor Chang | d8aa9d5 | 2021-01-05 23:49:57 +0000 | [diff] [blame] | 208 | |
| 209 | /** Mutates this MeasureUnitImpl to take the reciprocal. */ |
| 210 | void takeReciprocal(UErrorCode& status); |
| 211 | |
| 212 | /** |
| 213 | * Mutates this MeasureUnitImpl to append a single unit. |
| 214 | * |
| 215 | * @return true if a new item was added. If unit is the dimensionless unit, |
| 216 | * it is never added: the return value will always be false. |
| 217 | */ |
| 218 | bool append(const SingleUnitImpl& singleUnit, UErrorCode& status); |
| 219 | |
| 220 | /** The complexity, either SINGLE, COMPOUND, or MIXED. */ |
| 221 | UMeasureUnitComplexity complexity = UMEASURE_UNIT_SINGLE; |
| 222 | |
| 223 | /** |
| 224 | * The list of simple units. These may be summed or multiplied, based on the |
| 225 | * value of the complexity field. |
| 226 | * |
| 227 | * The "dimensionless" unit (SingleUnitImpl default constructor) must not be |
| 228 | * added to this list. |
| 229 | */ |
| 230 | MaybeStackVector<SingleUnitImpl> units; |
| 231 | |
| 232 | /** |
| 233 | * The full unit identifier. Owned by the MeasureUnitImpl. Empty if not computed. |
| 234 | */ |
| 235 | CharString identifier; |
| 236 | }; |
| 237 | |
Victor Chang | d8aa9d5 | 2021-01-05 23:49:57 +0000 | [diff] [blame] | 238 | U_NAMESPACE_END |
| 239 | |
| 240 | #endif /* #if !UCONFIG_NO_FORMATTING */ |
| 241 | #endif //__MEASUNIT_IMPL_H__ |