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

#include <bytestrie.h>

Inheritance diagram for icu::BytesTrie:

Data Structures
class	Iterator
	Iterator for all of the (byte sequence, value) pairs in a BytesTrie. More...

class	State
	BytesTrie state object, for saving a trie's current state and resetting the trie back to this state later. More...

Public Member Functions
	BytesTrie (const void *trieBytes)
	Constructs a BytesTrie reader instance.

	~BytesTrie ()
	Destructor.

	BytesTrie (const BytesTrie &other)
	Copy constructor, copies the other trie reader object and its state, but not the byte array which will be shared.

BytesTrie &	reset ()
	Resets this trie to its initial state.

uint64_t	getState64 () const
	Returns the state of this trie as a 64-bit integer.

BytesTrie &	resetToState64 (uint64_t state)
	Resets this trie to the saved state.

const BytesTrie &	saveState (State &state) const
	Saves the state of this trie.

BytesTrie &	resetToState (const State &state)
	Resets this trie to the saved state.

UStringTrieResult	current () const
	Determines whether the byte sequence so far matches, whether it has a value, and whether another input byte can continue a matching byte sequence.

UStringTrieResult	first (int32_t inByte)
	Traverses the trie from the initial state for this input byte.

UStringTrieResult	next (int32_t inByte)
	Traverses the trie from the current state for this input byte.

UStringTrieResult	next (const char *s, int32_t length)
	Traverses the trie from the current state for this byte sequence.

int32_t	getValue () const
	Returns a matching byte sequence'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 byte sequences reachable from the current state map to the same value.

int32_t	getNextBytes (ByteSink &out) const
	Finds each byte which continues the byte sequence from the current state.

Friends
class	BytesTrieBuilder

class	::BytesTrieTest

Detailed Description

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

Traverses a byte-serialized data structure with minimal state, for mapping byte 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 55 of file bytestrie.h.

Constructor & Destructor Documentation

◆ BytesTrie() [1/2]

icu::BytesTrie::BytesTrie ( const void * trieBytes )

inline

Constructs a BytesTrie reader instance.

The trieBytes must contain a copy of a byte sequence from the BytesTrieBuilder, starting with the first byte of that sequence. The BytesTrie object will not read more bytes than the BytesTrieBuilder generated in the corresponding build() call.

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

Parameters

trieBytes The byte array that contains the serialized trie.

Stable:: ICU 4.8

Definition at line 71 of file bytestrie.h.

◆ ~BytesTrie()

icu::BytesTrie::~BytesTrie ( )

Destructor.

Stable:: ICU 4.8

◆ BytesTrie() [2/2]

icu::BytesTrie::BytesTrie ( const BytesTrie & other )

inline

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

(Shallow copy.)

Parameters

other Another BytesTrie object.

Stable:: ICU 4.8

Definition at line 87 of file bytestrie.h.

Member Function Documentation

◆ current()

UStringTrieResult icu::BytesTrie::current ( ) const

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

Returns: The match/value Result.

Stable:: ICU 4.8

◆ first()

UStringTrieResult icu::BytesTrie::first ( int32_t inByte )

inline

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

Equivalent to reset().next(inByte).

Parameters

inByte Input byte value. Values -0x100..-1 are treated like 0..0xff. Values below -0x100 and above 0xff will never match.

Returns: The match/value Result.

Stable:: ICU 4.8

Definition at line 203 of file bytestrie.h.

◆ getNextBytes()

int32_t icu::BytesTrie::getNextBytes ( ByteSink & out ) const

Finds each byte which continues the byte sequence from the current state.

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

Parameters

out	Each next byte is appended to this object. (Only uses the out.Append(s, length) method.)

Returns: the number of bytes which continue the byte sequence from here

Stable:: ICU 4.8

◆ getState64()

uint64_t icu::BytesTrie::getState64 ( ) const

inline

Returns the state of this trie as a 64-bit integer.

The state value is never 0.

Returns: opaque state value

See also: resetToState64

Stable:: ICU 65

Definition at line 110 of file bytestrie.h.

◆ getValue()

int32_t icu::BytesTrie::getValue ( ) const

inline

Returns a matching byte sequence'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 byte sequence so far.

Stable:: ICU 4.8

Definition at line 246 of file bytestrie.h.

◆ hasUniqueValue()

UBool icu::BytesTrie::hasUniqueValue ( int32_t & uniqueValue ) const

inline

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

Parameters

uniqueValue Receives the unique value, if this function returns true. (output-only)

Returns: true if all byte sequences reachable from the current state map to the same value.

Stable:: ICU 4.8

Definition at line 262 of file bytestrie.h.

◆ next() [1/2]

UStringTrieResult icu::BytesTrie::next	(	const char *	s,
		int32_t	length
	)

Traverses the trie from the current state for this byte sequence.

Equivalent to

Result result=current();
for(each c in s)
  if(!USTRINGTRIE_HAS_NEXT(result)) return USTRINGTRIE_NO_MATCH;
  result=next(c);
return result;

Parameters

s	A string or byte sequence. Can be nullptr if length is 0.
length	The length of the byte sequence. Can be -1 if NUL-terminated.

Returns: The match/value Result.

Stable:: ICU 4.8

◆ next() [2/2]

UStringTrieResult icu::BytesTrie::next ( int32_t inByte )

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

Parameters

inByte Input byte value. Values -0x100..-1 are treated like 0..0xff. Values below -0x100 and above 0xff will never match.

Returns: The match/value Result.

Stable:: ICU 4.8

◆ reset()

BytesTrie & icu::BytesTrie::reset ( )

inline

Resets this trie to its initial state.

Returns: *this

Stable:: ICU 4.8

Definition at line 96 of file bytestrie.h.

◆ resetToState()

BytesTrie & icu::BytesTrie::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

state The State object which holds a saved trie state.

Returns: *this

See also: saveState; reset

Stable:: ICU 4.8

Definition at line 179 of file bytestrie.h.

◆ resetToState64()

BytesTrie & icu::BytesTrie::resetToState64 ( uint64_t state )

inline

Resets this trie to the saved state.

Unlike resetToState(State), the 64-bit state value must be from getState64() from the same trie object or from one initialized the exact same way. Because of no validation, this method is faster.

Parameters

state The opaque trie state value from getState64().

Returns: *this

See also: getState64; resetToState; reset

Stable:: ICU 65

Definition at line 129 of file bytestrie.h.

◆ saveState()

const BytesTrie & icu::BytesTrie::saveState ( State & state ) const

inline

Saves the state of this trie.

Parameters

state The State object to hold the trie's state.

Returns: *this

See also: resetToState

Stable:: ICU 4.8

Definition at line 162 of file bytestrie.h.

Friends And Related Symbol Documentation

◆ ::BytesTrieTest

friend class ::BytesTrieTest

friend

Definition at line 383 of file bytestrie.h.

◆ BytesTrieBuilder

friend class BytesTrieBuilder

friend

Definition at line 382 of file bytestrie.h.

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

common/unicode/bytestrie.h

Data Structures

Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ BytesTrie() [1/2]

◆ ~BytesTrie()

◆ BytesTrie() [2/2]

Member Function Documentation

◆ current()

◆ first()

◆ getNextBytes()

◆ getState64()

◆ getValue()

◆ hasUniqueValue()

◆ next() [1/2]

◆ next() [2/2]

◆ reset()

◆ resetToState()

◆ resetToState64()

◆ saveState()

Friends And Related Symbol Documentation

◆ ::BytesTrieTest

◆ BytesTrieBuilder