ICU 76.1 76.1
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umutablecptrie.h File Reference

C API: This file defines a mutable Unicode code point trie. More...

#include "unicode/utypes.h"
#include "unicode/ucpmap.h"
#include "unicode/ucptrie.h"
#include "unicode/utf8.h"
#include "unicode/localpointer.h"

Go to the source code of this file.

Namespaces

namespace  icu
 File coll.h.
 

Typedefs

typedef struct UMutableCPTrie UMutableCPTrie
 Mutable Unicode code point trie.
 

Functions

U_CAPI UMutableCPTrieumutablecptrie_open (uint32_t initialValue, uint32_t errorValue, UErrorCode *pErrorCode)
 Creates a mutable trie that initially maps each Unicode code point to the same value.
 
U_CAPI UMutableCPTrieumutablecptrie_clone (const UMutableCPTrie *other, UErrorCode *pErrorCode)
 Clones a mutable trie.
 
U_CAPI void umutablecptrie_close (UMutableCPTrie *trie)
 Closes a mutable trie and releases associated memory.
 
U_CAPI UMutableCPTrieumutablecptrie_fromUCPMap (const UCPMap *map, UErrorCode *pErrorCode)
 Creates a mutable trie with the same contents as the UCPMap.
 
U_CAPI UMutableCPTrieumutablecptrie_fromUCPTrie (const UCPTrie *trie, UErrorCode *pErrorCode)
 Creates a mutable trie with the same contents as the immutable one.
 
U_CAPI uint32_t umutablecptrie_get (const UMutableCPTrie *trie, UChar32 c)
 Returns the value for a code point as stored in the trie.
 
U_CAPI UChar32 umutablecptrie_getRange (const UMutableCPTrie *trie, 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.
 
U_CAPI void umutablecptrie_set (UMutableCPTrie *trie, UChar32 c, uint32_t value, UErrorCode *pErrorCode)
 Sets a value for a code point.
 
U_CAPI void umutablecptrie_setRange (UMutableCPTrie *trie, UChar32 start, UChar32 end, uint32_t value, UErrorCode *pErrorCode)
 Sets a value for each code point [start..end].
 
U_CAPI UCPTrieumutablecptrie_buildImmutable (UMutableCPTrie *trie, UCPTrieType type, UCPTrieValueWidth valueWidth, UErrorCode *pErrorCode)
 Compacts the data and builds an immutable UCPTrie according to the parameters.
 

Detailed Description

C API: This file defines a mutable Unicode code point trie.

See also
UCPTrie
UMutableCPTrie

Definition in file umutablecptrie.h.

Typedef Documentation

◆ UMutableCPTrie

Mutable Unicode code point trie.

Fast map from Unicode code points (U+0000..U+10FFFF) to 32-bit integer values. For details see https://icu.unicode.org/design/struct/utrie

Setting values (especially ranges) and lookup is fast. The mutable trie is only somewhat space-efficient. It builds a compacted, immutable UCPTrie.

This trie can be modified while iterating over its contents. For example, it is possible to merge its values with those from another set of ranges (e.g., another mutable or immutable trie): Iterate over those source ranges; for each of them iterate over this trie; add the source value into the value of each trie range.

See also
UCPTrie
umutablecptrie_buildImmutable
Stable:
ICU 63

Definition at line 49 of file umutablecptrie.h.

Function Documentation

◆ umutablecptrie_buildImmutable()

U_CAPI UCPTrie * umutablecptrie_buildImmutable ( UMutableCPTrie trie,
UCPTrieType  type,
UCPTrieValueWidth  valueWidth,
UErrorCode pErrorCode 
)

Compacts the data and builds an immutable UCPTrie according to the parameters.

After this, the mutable trie will be empty.

The mutable trie stores 32-bit values until buildImmutable() is called. If values shorter than 32 bits are to be stored in the immutable trie, then the upper bits are discarded. For example, when the mutable trie contains values 0x81, -0x7f, and 0xa581, and the value width is 8 bits, then each of these is stored as 0x81 and the immutable trie will return that as an unsigned value. (Some implementations may want to make productive temporary use of the upper bits until buildImmutable() discards them.)

Not every possible set of mappings can be built into a UCPTrie, because of limitations resulting from speed and space optimizations. Every Unicode assigned character can be mapped to a unique value. Typical data yields data structures far smaller than the limitations.

It is possible to construct extremely unusual mappings that exceed the data structure limits. In such a case this function will fail with a U_INDEX_OUTOFBOUNDS_ERROR.

Parameters
triethe trie trie
typeselects the trie type
valueWidthselects the number of bits in a trie data value; if smaller than 32 bits, then the values stored in the trie will be truncated first
pErrorCodean in/out ICU UErrorCode
See also
umutablecptrie_fromUCPTrie
Stable:
ICU 63

◆ umutablecptrie_clone()

U_CAPI UMutableCPTrie * umutablecptrie_clone ( const UMutableCPTrie other,
UErrorCode pErrorCode 
)

Clones a mutable trie.

You must umutablecptrie_close() the clone once you are done using it.

Parameters
otherthe trie to clone
pErrorCodean in/out ICU UErrorCode
Returns
the trie clone
Stable:
ICU 63

◆ umutablecptrie_close()

U_CAPI void umutablecptrie_close ( UMutableCPTrie trie)

Closes a mutable trie and releases associated memory.

Parameters
triethe trie
Stable:
ICU 63

◆ umutablecptrie_fromUCPMap()

U_CAPI UMutableCPTrie * umutablecptrie_fromUCPMap ( const UCPMap map,
UErrorCode pErrorCode 
)

Creates a mutable trie with the same contents as the UCPMap.

You must umutablecptrie_close() the mutable trie once you are done using it.

Parameters
mapthe source map
pErrorCodean in/out ICU UErrorCode
Returns
the mutable trie
Stable:
ICU 63

◆ umutablecptrie_fromUCPTrie()

U_CAPI UMutableCPTrie * umutablecptrie_fromUCPTrie ( const UCPTrie trie,
UErrorCode pErrorCode 
)

Creates a mutable trie with the same contents as the immutable one.

You must umutablecptrie_close() the mutable trie once you are done using it.

Parameters
triethe immutable trie
pErrorCodean in/out ICU UErrorCode
Returns
the mutable trie
Stable:
ICU 63

◆ umutablecptrie_get()

U_CAPI uint32_t umutablecptrie_get ( const UMutableCPTrie trie,
UChar32  c 
)

Returns the value for a code point as stored in the trie.

Parameters
triethe trie
cthe code point
Returns
the value
Stable:
ICU 63

◆ umutablecptrie_getRange()

U_CAPI UChar32 umutablecptrie_getRange ( const UMutableCPTrie trie,
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 trie. (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.)

The trie can be modified between calls to this function.

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.

See the same-signature ucptrie_getRange() for a code sample.

Parameters
triethe trie
startrange start
optiondefines whether surrogates are treated normally, or as having the surrogateValue; usually UCPMAP_RANGE_NORMAL
surrogateValuevalue for surrogates; ignored if option==UCPMAP_RANGE_NORMAL
filtera pointer to a function that may modify the trie data value, or NULL if the values from the trie are to be used unmodified
contextan opaque pointer that is passed on to the filter function
pValueif not NULL, receives the value that every code point start..end has; may have been modified by filter(context, trie value) if that function pointer is not NULL
Returns
the range end code point, or -1 if start is not a valid code point
Stable:
ICU 63

◆ umutablecptrie_open()

U_CAPI UMutableCPTrie * umutablecptrie_open ( uint32_t  initialValue,
uint32_t  errorValue,
UErrorCode pErrorCode 
)

Creates a mutable trie that initially maps each Unicode code point to the same value.

It uses 32-bit data values until umutablecptrie_buildImmutable() is called. umutablecptrie_buildImmutable() takes a valueWidth parameter which determines the number of bits in the data value in the resulting UCPTrie. You must umutablecptrie_close() the trie once you are done using it.

Parameters
initialValuethe initial value that is set for all code points
errorValuethe value for out-of-range code points and ill-formed UTF-8/16
pErrorCodean in/out ICU UErrorCode
Returns
the trie
Stable:
ICU 63

◆ umutablecptrie_set()

U_CAPI void umutablecptrie_set ( UMutableCPTrie trie,
UChar32  c,
uint32_t  value,
UErrorCode pErrorCode 
)

Sets a value for a code point.

Parameters
triethe trie
cthe code point
valuethe value
pErrorCodean in/out ICU UErrorCode
Stable:
ICU 63

◆ umutablecptrie_setRange()

U_CAPI void umutablecptrie_setRange ( UMutableCPTrie trie,
UChar32  start,
UChar32  end,
uint32_t  value,
UErrorCode pErrorCode 
)

Sets a value for each code point [start..end].

Faster and more space-efficient than setting the value for each code point separately.

Parameters
triethe trie
startthe first code point to get the value
endthe last code point to get the value (inclusive)
valuethe value
pErrorCodean in/out ICU UErrorCode
Stable:
ICU 63