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Diffstat (limited to 'intl/icu/source/common/unicode/ucpmap.h')
-rw-r--r-- | intl/icu/source/common/unicode/ucpmap.h | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/intl/icu/source/common/unicode/ucpmap.h b/intl/icu/source/common/unicode/ucpmap.h new file mode 100644 index 0000000000..a740bd160f --- /dev/null +++ b/intl/icu/source/common/unicode/ucpmap.h @@ -0,0 +1,158 @@ +// © 2018 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html + +// ucpmap.h +// created: 2018sep03 Markus W. Scherer + +#ifndef __UCPMAP_H__ +#define __UCPMAP_H__ + +#include "unicode/utypes.h" + +U_CDECL_BEGIN + +/** + * \file + * \brief C API: This file defines an abstract map from Unicode code points to integer values. + * + * @see UCPMap + * @see UCPTrie + * @see UMutableCPTrie + */ + +/** + * Abstract map from Unicode code points (U+0000..U+10FFFF) to integer values. + * + * @see UCPTrie + * @see UMutableCPTrie + * @stable ICU 63 + */ +typedef struct UCPMap UCPMap; + +/** + * Selectors for how ucpmap_getRange() etc. should report value ranges overlapping with surrogates. + * Most users should use UCPMAP_RANGE_NORMAL. + * + * @see ucpmap_getRange + * @see ucptrie_getRange + * @see umutablecptrie_getRange + * @stable ICU 63 + */ +enum UCPMapRangeOption { + /** + * ucpmap_getRange() enumerates all same-value ranges as stored in the map. + * Most users should use this option. + * @stable ICU 63 + */ + UCPMAP_RANGE_NORMAL, + /** + * ucpmap_getRange() enumerates all same-value ranges as stored in the map, + * except that lead surrogates (U+D800..U+DBFF) are treated as having the + * surrogateValue, which is passed to getRange() as a separate parameter. + * The surrogateValue is not transformed via filter(). + * See U_IS_LEAD(c). + * + * Most users should use UCPMAP_RANGE_NORMAL instead. + * + * This option is useful for maps that map surrogate code *units* to + * special values optimized for UTF-16 string processing + * or for special error behavior for unpaired surrogates, + * but those values are not to be associated with the lead surrogate code *points*. + * @stable ICU 63 + */ + UCPMAP_RANGE_FIXED_LEAD_SURROGATES, + /** + * ucpmap_getRange() enumerates all same-value ranges as stored in the map, + * except that all surrogates (U+D800..U+DFFF) are treated as having the + * surrogateValue, which is passed to getRange() as a separate parameter. + * The surrogateValue is not transformed via filter(). + * See U_IS_SURROGATE(c). + * + * Most users should use UCPMAP_RANGE_NORMAL instead. + * + * This option is useful for maps that map surrogate code *units* to + * special values optimized for UTF-16 string processing + * or for special error behavior for unpaired surrogates, + * but those values are not to be associated with the lead surrogate code *points*. + * @stable ICU 63 + */ + UCPMAP_RANGE_FIXED_ALL_SURROGATES +}; +#ifndef U_IN_DOXYGEN +typedef enum UCPMapRangeOption UCPMapRangeOption; +#endif + +/** + * Returns the value for a code point as stored in the map, with range checking. + * Returns an implementation-defined error value if c is not in the range 0..U+10FFFF. + * + * @param map the map + * @param c the code point + * @return the map value, + * or an implementation-defined error value if the code point is not in the range 0..U+10FFFF + * @stable ICU 63 + */ +U_CAPI uint32_t U_EXPORT2 +ucpmap_get(const UCPMap *map, UChar32 c); + +/** + * Callback function type: Modifies a map value. + * Optionally called by ucpmap_getRange()/ucptrie_getRange()/umutablecptrie_getRange(). + * The modified value will be returned by the getRange function. + * + * Can be used to ignore some of the value bits, + * make a filter for one of several values, + * return a value index computed from the map value, etc. + * + * @param context an opaque pointer, as passed into the getRange function + * @param value a value from the map + * @return the modified value + * @stable ICU 63 + */ +typedef uint32_t U_CALLCONV +UCPMapValueFilter(const void *context, uint32_t value); + +/** + * Returns the last code point such that all those from start to there have the same value. + * Can be used to efficiently iterate over all same-value ranges in a map. + * (This is normally faster than iterating over code points and get()ting each value, + * but much slower than a data structure that stores ranges directly.) + * + * If the UCPMapValueFilter function pointer is not NULL, then + * the value to be delivered is passed through that function, and the return value is the end + * of the range where all values are modified to the same actual value. + * The value is unchanged if that function pointer is NULL. + * + * Example: + * \code + * UChar32 start = 0, end; + * uint32_t value; + * while ((end = ucpmap_getRange(map, start, UCPMAP_RANGE_NORMAL, 0, + * NULL, NULL, &value)) >= 0) { + * // Work with the range start..end and its value. + * start = end + 1; + * } + * \endcode + * + * @param map the map + * @param start range start + * @param option defines whether surrogates are treated normally, + * or as having the surrogateValue; usually UCPMAP_RANGE_NORMAL + * @param surrogateValue value for surrogates; ignored if option==UCPMAP_RANGE_NORMAL + * @param filter a pointer to a function that may modify the map data value, + * or NULL if the values from the map are to be used unmodified + * @param context an opaque pointer that is passed on to the filter function + * @param pValue if not NULL, receives the value that every code point start..end has; + * may have been modified by filter(context, map value) + * if that function pointer is not NULL + * @return the range end code point, or -1 if start is not a valid code point + * @stable ICU 63 + */ +U_CAPI UChar32 U_EXPORT2 +ucpmap_getRange(const UCPMap *map, UChar32 start, + UCPMapRangeOption option, uint32_t surrogateValue, + UCPMapValueFilter *filter, const void *context, uint32_t *pValue); + +U_CDECL_END + +#endif |