ICU 64.2
64.2
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This file defines an abstract map from Unicode code points to integer values. More...
#include "unicode/utypes.h"
Go to the source code of this file.
Typedefs | |
typedef struct UCPMap | UCPMap |
Abstract map from Unicode code points (U+0000..U+10FFFF) to integer values. More... | |
typedef uint32_t | UCPMapValueFilter(const void *context, uint32_t value) |
Callback function type: Modifies a map value. More... | |
Enumerations | |
enum | UCPMapRangeOption { UCPMAP_RANGE_NORMAL, UCPMAP_RANGE_FIXED_LEAD_SURROGATES, UCPMAP_RANGE_FIXED_ALL_SURROGATES } |
Selectors for how ucpmap_getRange() etc. More... | |
Functions | |
U_CAPI uint32_t | ucpmap_get (const UCPMap *map, UChar32 c) |
Returns the value for a code point as stored in the map, with range checking. More... | |
U_CAPI UChar32 | ucpmap_getRange (const UCPMap *map, UChar32 start, UCPMapRangeOption option, uint32_t surrogateValue, UCPMapValueFilter *filter, const void *context, uint32_t *pValue) |
Returns the last code point such that all those from start to there have the same value. More... | |
This file defines an abstract map from Unicode code points to integer values.
Definition in file ucpmap.h.
Abstract map from Unicode code points (U+0000..U+10FFFF) to integer values.
typedef uint32_t UCPMapValueFilter(const void *context, uint32_t value) |
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.
context | an opaque pointer, as passed into the getRange function |
value | a value from the map |
enum UCPMapRangeOption |
Selectors for how ucpmap_getRange() etc.
should report value ranges overlapping with surrogates. Most users should use UCPMAP_RANGE_NORMAL.
Enumerator | |
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UCPMAP_RANGE_NORMAL | ucpmap_getRange() enumerates all same-value ranges as stored in the map. Most users should use this option.
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UCPMAP_RANGE_FIXED_LEAD_SURROGATES | 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.
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UCPMAP_RANGE_FIXED_ALL_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.
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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.
map | the map |
c | the code point |
U_CAPI UChar32 ucpmap_getRange | ( | const UCPMap * | map, |
UChar32 | start, | ||
UCPMapRangeOption | option, | ||
uint32_t | surrogateValue, | ||
UCPMapValueFilter * | filter, | ||
const void * | context, | ||
uint32_t * | pValue | ||
) |
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:
map | the map |
start | range start |
option | defines whether surrogates are treated normally, or as having the surrogateValue; usually UCPMAP_RANGE_NORMAL |
surrogateValue | value for surrogates; ignored if option==UCPMAP_RANGE_NORMAL |
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 |
context | an opaque pointer that is passed on to the filter function |
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 |