ICU 70.1  70.1
localematcher.h
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1 // © 2019 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 
4 // localematcher.h
5 // created: 2019may08 Markus W. Scherer
6 
7 #ifndef __LOCALEMATCHER_H__
8 #define __LOCALEMATCHER_H__
9 
10 #include "unicode/utypes.h"
11 
12 #if U_SHOW_CPLUSPLUS_API
13 
14 #include "unicode/locid.h"
15 #include "unicode/stringpiece.h"
16 #include "unicode/uobject.h"
17 
43 };
44 #ifndef U_IN_DOXYGEN
46 #endif
47 
89 };
90 #ifndef U_IN_DOXYGEN
92 #endif
93 
125 };
126 #ifndef U_IN_DOXYGEN
128 #endif
129 
130 struct UHashtable;
131 
132 U_NAMESPACE_BEGIN
133 
134 struct LSR;
135 
136 class LocaleDistance;
137 class LocaleLsrIterator;
138 class UVector;
139 class XLikelySubtags;
140 
185 public:
192  class U_COMMON_API Result : public UMemory {
193  public:
202 
209 
218 
226  inline const Locale *getDesiredLocale() const { return desiredLocale; }
227 
237  inline const Locale *getSupportedLocale() const { return supportedLocale; }
238 
246  inline int32_t getDesiredIndex() const { return desiredIndex; }
247 
258  inline int32_t getSupportedIndex() const { return supportedIndex; }
259 
273 
274  private:
275  Result(const Locale *desired, const Locale *supported,
276  int32_t desIndex, int32_t suppIndex, UBool owned) :
277  desiredLocale(desired), supportedLocale(supported),
278  desiredIndex(desIndex), supportedIndex(suppIndex),
279  desiredIsOwned(owned) {}
280 
281  Result(const Result &other) = delete;
282  Result &operator=(const Result &other) = delete;
283 
284  const Locale *desiredLocale;
285  const Locale *supportedLocale;
286  int32_t desiredIndex;
287  int32_t supportedIndex;
288  UBool desiredIsOwned;
289 
290  friend class LocaleMatcher;
291  };
292 
299  class U_COMMON_API Builder : public UMemory {
300  public:
307  Builder() {}
308 
317 
324 
333 
346 
357 
371  template<typename Iter>
372  Builder &setSupportedLocales(Iter begin, Iter end) {
373  if (U_FAILURE(errorCode_)) { return *this; }
374  clearSupportedLocales();
375  while (begin != end) {
376  addSupportedLocale(*begin++);
377  }
378  return *this;
379  }
380 
396  template<typename Iter, typename Conv>
397  Builder &setSupportedLocalesViaConverter(Iter begin, Iter end, Conv converter) {
398  if (U_FAILURE(errorCode_)) { return *this; }
399  clearSupportedLocales();
400  while (begin != end) {
401  addSupportedLocale(converter(*begin++));
402  }
403  return *this;
404  }
405 
415 
425 
436  Builder &setDefaultLocale(const Locale *defaultLocale);
437 
449 
459 
469  if (U_SUCCESS(errorCode_)) {
470  direction_ = direction;
471  }
472  return *this;
473  }
474 
496  Builder &setMaxDistance(const Locale &desired, const Locale &supported);
497 
508  UBool copyErrorTo(UErrorCode &outErrorCode) const;
509 
520  LocaleMatcher build(UErrorCode &errorCode) const;
521 
522  private:
523  friend class LocaleMatcher;
524 
525  Builder(const Builder &other) = delete;
526  Builder &operator=(const Builder &other) = delete;
527 
528  void clearSupportedLocales();
529  bool ensureSupportedLocaleVector();
530 
531  UErrorCode errorCode_ = U_ZERO_ERROR;
532  UVector *supportedLocales_ = nullptr;
533  int32_t thresholdDistance_ = -1;
535  Locale *defaultLocale_ = nullptr;
536  bool withDefault_ = true;
539  Locale *maxDistanceDesired_ = nullptr;
540  Locale *maxDistanceSupported_ = nullptr;
541  };
542 
543  // FYI No public LocaleMatcher constructors in C++; use the Builder.
544 
552 
558 
568 
579  const Locale *getBestMatch(const Locale &desiredLocale, UErrorCode &errorCode) const;
580 
591  const Locale *getBestMatch(Locale::Iterator &desiredLocales, UErrorCode &errorCode) const;
592 
607  const Locale *getBestMatchForListString(StringPiece desiredLocaleList, UErrorCode &errorCode) const;
608 
621  Result getBestMatchResult(const Locale &desiredLocale, UErrorCode &errorCode) const;
622 
635  Result getBestMatchResult(Locale::Iterator &desiredLocales, UErrorCode &errorCode) const;
636 
650  UBool isMatch(const Locale &desired, const Locale &supported, UErrorCode &errorCode) const;
651 
652 #ifndef U_HIDE_INTERNAL_API
671  double internalMatch(const Locale &desired, const Locale &supported, UErrorCode &errorCode) const;
672 #endif // U_HIDE_INTERNAL_API
673 
674 private:
675  LocaleMatcher(const Builder &builder, UErrorCode &errorCode);
676  LocaleMatcher(const LocaleMatcher &other) = delete;
677  LocaleMatcher &operator=(const LocaleMatcher &other) = delete;
678 
679  int32_t putIfAbsent(const LSR &lsr, int32_t i, int32_t suppLength, UErrorCode &errorCode);
680 
681  int32_t getBestSuppIndex(LSR desiredLSR, LocaleLsrIterator *remainingIter, UErrorCode &errorCode) const;
682 
683  const XLikelySubtags &likelySubtags;
684  const LocaleDistance &localeDistance;
685  int32_t thresholdDistance;
686  int32_t demotionPerDesiredLocale;
687  ULocMatchFavorSubtag favorSubtag;
688  ULocMatchDirection direction;
689 
690  // These are in input order.
691  const Locale ** supportedLocales;
692  LSR *lsrs;
693  int32_t supportedLocalesLength;
694  // These are in preference order: 1. Default locale 2. paradigm locales 3. others.
695  UHashtable *supportedLsrToIndex; // Map<LSR, Integer>
696  // Array versions of the supportedLsrToIndex keys and values.
697  // The distance lookup loops over the supportedLSRs and returns the index of the best match.
698  const LSR **supportedLSRs;
699  int32_t *supportedIndexes;
700  int32_t supportedLSRsLength;
701  Locale *ownedDefaultLocale;
702  const Locale *defaultLocale;
703 };
704 
705 U_NAMESPACE_END
706 
707 #endif // U_SHOW_CPLUSPLUS_API
708 #endif // __LOCALEMATCHER_H__
LocaleMatcher builder.
Builder & setDirection(ULocMatchDirection direction)
Option for whether to include or ignore one-way (fallback) match data.
Builder & setFavorSubtag(ULocMatchFavorSubtag subtag)
If ULOCMATCH_FAVOR_SCRIPT, then the language differences are smaller than script differences.
Builder & addSupportedLocale(const Locale &locale)
Adds another supported locale.
Builder & setSupportedLocales(Locale::Iterator &locales)
Copies the supported locales, preserving iteration order.
Builder & setSupportedLocales(Iter begin, Iter end)
Copies the supported locales from the begin/end range, preserving iteration order.
Builder & setSupportedLocalesViaConverter(Iter begin, Iter end, Conv converter)
Copies the supported locales from the begin/end range, preserving iteration order.
LocaleMatcher build(UErrorCode &errorCode) const
Builds and returns a new locale matcher.
Builder & operator=(Builder &&src) U_NOEXCEPT
Move assignment; might modify the source.
Builder & setSupportedLocalesFromListString(StringPiece locales)
Parses an Accept-Language string (RFC 2616 Section 14.4), such as "af, en, fr;q=0....
Builder & setMaxDistance(const Locale &desired, const Locale &supported)
Sets the maximum distance for an acceptable match.
Builder & setNoDefaultLocale()
Sets no default locale.
Builder & setDefaultLocale(const Locale *defaultLocale)
Sets the default locale; if nullptr, or if it is not set explicitly, then the first supported locale ...
Builder(Builder &&src) U_NOEXCEPT
Move constructor; might modify the source.
Builder & setDemotionPerDesiredLocale(ULocMatchDemotion demotion)
Option for whether all desired locales are treated equally or earlier ones are preferred (this is the...
UBool copyErrorTo(UErrorCode &outErrorCode) const
Sets the UErrorCode if an error occurred while setting parameters.
Builder()
Constructs a builder used in chaining parameters for building a LocaleMatcher.
Data for the best-matching pair of a desired and a supported locale.
int32_t getSupportedIndex() const
Returns the index of the best-matching supported locale in the constructor’s or builder’s input order...
Result & operator=(Result &&src) U_NOEXCEPT
Move assignment; might modify the source.
const Locale * getSupportedLocale() const
Returns the best-matching supported locale.
int32_t getDesiredIndex() const
Returns the index of the best-matching desired locale in the input Iterable order.
Locale makeResolvedLocale(UErrorCode &errorCode) const
Takes the best-matching supported locale and adds relevant fields of the best-matching desired locale...
const Locale * getDesiredLocale() const
Returns the best-matching desired locale.
Result(Result &&src) U_NOEXCEPT
Move constructor; might modify the source.
Immutable class that picks the best match between a user's desired locales and an application's suppo...
LocaleMatcher(LocaleMatcher &&src) U_NOEXCEPT
Move copy constructor; might modify the source.
const Locale * getBestMatch(const Locale &desiredLocale, UErrorCode &errorCode) const
Returns the supported locale which best matches the desired locale.
UBool isMatch(const Locale &desired, const Locale &supported, UErrorCode &errorCode) const
Returns true if the pair of locales matches acceptably.
Result getBestMatchResult(const Locale &desiredLocale, UErrorCode &errorCode) const
Returns the best match between the desired locale and the supported locales.
Result getBestMatchResult(Locale::Iterator &desiredLocales, UErrorCode &errorCode) const
Returns the best match between the desired and supported locales.
LocaleMatcher & operator=(LocaleMatcher &&src) U_NOEXCEPT
Move assignment operator; might modify the source.
double internalMatch(const Locale &desired, const Locale &supported, UErrorCode &errorCode) const
Returns a fraction between 0 and 1, where 1 means that the languages are a perfect match,...
const Locale * getBestMatchForListString(StringPiece desiredLocaleList, UErrorCode &errorCode) const
Parses an Accept-Language string (RFC 2616 Section 14.4), such as "af, en, fr;q=0....
~LocaleMatcher()
Destructor.
const Locale * getBestMatch(Locale::Iterator &desiredLocales, UErrorCode &errorCode) const
Returns the supported locale which best matches one of the desired locales.
A Locale iterator interface similar to a Java Iterator<Locale>.
Definition: locid.h:1014
A Locale object represents a specific geographical, political, or cultural region.
Definition: locid.h:195
A string-like object that points to a sized piece of memory.
Definition: stringpiece.h:60
UMemory is the common ICU base class.
Definition: uobject.h:115
ULocMatchDemotion
Builder option for whether all desired locales are treated equally or earlier ones are preferred.
Definition: localematcher.h:55
@ ULOCMATCH_DEMOTION_REGION
Earlier desired locales are preferred.
Definition: localematcher.h:88
@ ULOCMATCH_DEMOTION_NONE
All desired locales are treated equally.
Definition: localematcher.h:61
ULocMatchDirection
Builder option for whether to include or ignore one-way (fallback) match data.
@ ULOCMATCH_DIRECTION_ONLY_TWO_WAY
Locale matching limited to two-way matches including e.g.
@ ULOCMATCH_DIRECTION_WITH_ONE_WAY
Locale matching includes one-way matches such as Breton→French.
ULocMatchFavorSubtag
Builder option for whether the language subtag or the script subtag is most important.
Definition: localematcher.h:29
@ ULOCMATCH_FAVOR_SCRIPT
Makes script differences matter relatively more than language differences.
Definition: localematcher.h:42
@ ULOCMATCH_FAVOR_LANGUAGE
Language differences are most important, then script differences, then region differences.
Definition: localematcher.h:36
C++ API: Locale ID object.
struct UHashtable UHashtable
Definition: msgfmt.h:43
#define U_NOEXCEPT
"noexcept" if supported, otherwise empty.
Definition: platform.h:529
C++ API: StringPiece: Read-only byte string wrapper class.
int8_t UBool
The ICU boolean type, a signed-byte integer.
Definition: umachine.h:269
C++ API: Common ICU base class UObject.
Basic definitions for ICU, for both C and C++ APIs.
UErrorCode
Standard ICU4C error code type, a substitute for exceptions.
Definition: utypes.h:415
@ U_ZERO_ERROR
No error, no warning.
Definition: utypes.h:449
#define U_FAILURE(x)
Does the error code indicate a failure?
Definition: utypes.h:717
#define U_SUCCESS(x)
Does the error code indicate success?
Definition: utypes.h:712
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside.
Definition: utypes.h:300