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icu::UCharsTrie Class Reference

Light-weight, non-const reader class for a UCharsTrie. More...

#include <ucharstrie.h>

Inheritance diagram for icu::UCharsTrie:
icu::UMemory

Data Structures

class  Iterator
 Iterator for all of the (string, value) pairs in a UCharsTrie. More...
class  State
 UCharsTrie state object, for saving a trie's current state and resetting the trie back to this state later. More...

Public Member Functions

 UCharsTrie (const UChar *trieUChars)
 Constructs a UCharsTrie reader instance.
 ~UCharsTrie ()
 Destructor.
 UCharsTrie (const UCharsTrie &other)
 Copy constructor, copies the other trie reader object and its state, but not the UChar array which will be shared.
UCharsTriereset ()
 Resets this trie to its initial state.
const UCharsTriesaveState (State &state) const
 Saves the state of this trie.
UCharsTrieresetToState (const State &state)
 Resets this trie to the saved state.
UStringTrieResult current () const
 Determines whether the string so far matches, whether it has a value, and whether another input UChar can continue a matching string.
UStringTrieResult first (int32_t uchar)
 Traverses the trie from the initial state for this input UChar.
UStringTrieResult firstForCodePoint (UChar32 cp)
 Traverses the trie from the initial state for the one or two UTF-16 code units for this input code point.
UStringTrieResult next (int32_t uchar)
 Traverses the trie from the current state for this input UChar.
UStringTrieResult nextForCodePoint (UChar32 cp)
 Traverses the trie from the current state for the one or two UTF-16 code units for this input code point.
UStringTrieResult next (const UChar *s, int32_t length)
 Traverses the trie from the current state for this string.
int32_t getValue () const
 Returns a matching string's value if called immediately after current()/first()/next() returned USTRINGTRIE_INTERMEDIATE_VALUE or USTRINGTRIE_FINAL_VALUE.
UBool hasUniqueValue (int32_t &uniqueValue) const
 Determines whether all strings reachable from the current state map to the same value.
int32_t getNextUChars (Appendable &out) const
 Finds each UChar which continues the string from the current state.

Friends

class UCharsTrieBuilder

Detailed Description

Light-weight, non-const reader class for a UCharsTrie.

Traverses a UChar-serialized data structure with minimal state, for mapping strings (16-bit-unit sequences) to non-negative integer values.

This class owns the serialized trie data only if it was constructed by the builder's build() method. The public constructor and the copy constructor only alias the data (only copy the pointer). There is no assignment operator.

This class is not intended for public subclassing.

Stable:
ICU 4.8

Definition at line 48 of file ucharstrie.h.

Constructor & Destructor Documentation

icu::UCharsTrie::UCharsTrie ( const UChar trieUChars)
inline

Constructs a UCharsTrie reader instance.

The trieUChars must contain a copy of a UChar sequence from the UCharsTrieBuilder, starting with the first UChar of that sequence. The UCharsTrie object will not read more UChars than the UCharsTrieBuilder generated in the corresponding build() call.

The array is not copied/cloned and must not be modified while the UCharsTrie object is in use.

Parameters
trieUCharsThe UChar array that contains the serialized trie.
Stable:
ICU 4.8

Definition at line 64 of file ucharstrie.h.

icu::UCharsTrie::~UCharsTrie ( )

Destructor.

Stable:
ICU 4.8
icu::UCharsTrie::UCharsTrie ( const UCharsTrie other)
inline

Copy constructor, copies the other trie reader object and its state, but not the UChar array which will be shared.

(Shallow copy.)

Parameters
otherAnother UCharsTrie object.
Stable:
ICU 4.8

Definition at line 80 of file ucharstrie.h.

Member Function Documentation

UStringTrieResult icu::UCharsTrie::current ( ) const

Determines whether the string so far matches, whether it has a value, and whether another input UChar can continue a matching string.

Returns
The match/value Result.
Stable:
ICU 4.8
UStringTrieResult icu::UCharsTrie::first ( int32_t  uchar)
inline

Traverses the trie from the initial state for this input UChar.

Equivalent to reset().next(uchar).

Parameters
ucharInput char value. Values below 0 and above 0xffff will never match.
Returns
The match/value Result.
Stable:
ICU 4.8

Definition at line 162 of file ucharstrie.h.

UStringTrieResult icu::UCharsTrie::firstForCodePoint ( UChar32  cp)

Traverses the trie from the initial state for the one or two UTF-16 code units for this input code point.

Equivalent to reset().nextForCodePoint(cp).

Parameters
cpA Unicode code point 0..0x10ffff.
Returns
The match/value Result.
Stable:
ICU 4.8
int32_t icu::UCharsTrie::getNextUChars ( Appendable out) const

Finds each UChar which continues the string from the current state.

That is, each UChar c for which it would be next(c)!=USTRINGTRIE_NO_MATCH now.

Parameters
outEach next UChar is appended to this object.
Returns
the number of UChars which continue the string from here
Stable:
ICU 4.8
int32_t icu::UCharsTrie::getValue ( ) const
inline

Returns a matching string's value if called immediately after current()/first()/next() returned USTRINGTRIE_INTERMEDIATE_VALUE or USTRINGTRIE_FINAL_VALUE.

getValue() can be called multiple times.

Do not call getValue() after USTRINGTRIE_NO_MATCH or USTRINGTRIE_NO_VALUE!

Returns
The value for the string so far.
Stable:
ICU 4.8

Definition at line 220 of file ucharstrie.h.

UBool icu::UCharsTrie::hasUniqueValue ( int32_t &  uniqueValue) const
inline

Determines whether all strings reachable from the current state map to the same value.

Parameters
uniqueValueReceives the unique value, if this function returns TRUE. (output-only)
Returns
TRUE if all strings reachable from the current state map to the same value.
Stable:
ICU 4.8

Definition at line 237 of file ucharstrie.h.

References FALSE, and NULL.

UStringTrieResult icu::UCharsTrie::next ( int32_t  uchar)

Traverses the trie from the current state for this input UChar.

Parameters
ucharInput char value. Values below 0 and above 0xffff will never match.
Returns
The match/value Result.
Stable:
ICU 4.8
UStringTrieResult icu::UCharsTrie::next ( const UChar s,
int32_t  length 
)

Traverses the trie from the current state for this string.

Equivalent to

Result result=current();
for(each c in s)
result=next(c);
return result;
Parameters
sA string. Can be NULL if length is 0.
lengthThe length of the string. Can be -1 if NUL-terminated.
Returns
The match/value Result.
Stable:
ICU 4.8
UStringTrieResult icu::UCharsTrie::nextForCodePoint ( UChar32  cp)

Traverses the trie from the current state for the one or two UTF-16 code units for this input code point.

Parameters
cpA Unicode code point 0..0x10ffff.
Returns
The match/value Result.
Stable:
ICU 4.8
UCharsTrie& icu::UCharsTrie::reset ( void  )
inline

Resets this trie to its initial state.

Returns
*this
Stable:
ICU 4.8

Definition at line 89 of file ucharstrie.h.

UCharsTrie& icu::UCharsTrie::resetToState ( const State state)
inline

Resets this trie to the saved state.

If the state object contains no state, or the state of a different trie, then this trie remains unchanged.

Parameters
stateThe State object which holds a saved trie state.
Returns
*this
See Also
saveState
reset
Stable:
ICU 4.8

Definition at line 139 of file ucharstrie.h.

References NULL.

const UCharsTrie& icu::UCharsTrie::saveState ( State state) const
inline

Saves the state of this trie.

Parameters
stateThe State object to hold the trie's state.
Returns
*this
See Also
resetToState
Stable:
ICU 4.8

Definition at line 122 of file ucharstrie.h.


The documentation for this class was generated from the following file: