scuffed-code/icu4c/source/i18n/wdbktbl.h

120 lines
3.5 KiB
C++

/*
*****************************************************************************************
*
* Copyright © {1997-1999}, International Business Machines Corporation and others. All Rights Reserved.
*****************************************************************************************
*
* File WDBKTBL.H
*
* WordBreakTable implements a state transition table.
*
* @package Text and International
* @category Text Scanning
*
* Modification History:
*
* Date Name Description
* 02/18/97 aliu Converted from OpenClass. Made statics const.
*****************************************************************************************
*/
#ifndef WDBKTBL_H
#define WDBKTBL_H
#include "unicode/utypes.h"
#include "txtbdat.h"
/**
* This class implements a state transition table.
* After each transition, using the get method, the
* new state is returned along with information about
* the state change (ex. was it a "marked" transition").
* For efficiency, none of the arguments to any of these
* methods are validated.
*/
class WordBreakTable {
public:
// For convenience
typedef TextBoundaryData::Node Node;
typedef TextBoundaryData::Type Type;
/**
* Construct a table from the provided data. See CharacterBreakData or
* the other TextBoundaryData subclasses for examples. Each row represents
* a state, each column within a row represents a transition. The values
* in the table represent the new state and mark information.
* @param cols number of columns in the table (transitions)
* @param data an encoded byte array containing state and transition data
* @param data_length the length of the byte array data
*/
WordBreakTable(int32_t cols, const Node data[], int32_t data_length);
/**
* Get the resulting state moving from oldState accepting input.
* @param oldState current state
* @param input input
* @return resulting state and transition data
*/
Node get(Node oldState, Type input) const;
/**
* Checks to see if the transition into the specified state was "marked."
* @param state the state as returned by get, initialState, or endState
* @return true if transition into state was marked.
*/
bool_t isMarkState(Node state) const;
/**
* Check to see if the state is the end state
* @param state the state to check
* @return true if state is an end state
*/
bool_t isEndState(Node state) const;
/**
* Get the initial state
* @return the initial state
*/
Node initialState(void) const;
private:
static const Node kMark_mask;
static const Node kIndex_mask;
static const Node kInitial_state;
static const Node kEnd_state;
const TextBoundaryData::Node* fData;
int32_t fData_length;
int32_t fCols;
};
// -------------------------------------
inline WordBreakTable::Node
WordBreakTable::get(WordBreakTable::Node oldState, WordBreakTable::Type input) const
{
return fData[(oldState & kIndex_mask) * fCols + input];
}
inline bool_t
WordBreakTable::isMarkState(WordBreakTable::Node state) const
{
return (state & kMark_mask) != 0;
}
inline bool_t
WordBreakTable::isEndState(WordBreakTable::Node state) const
{
return (state & kIndex_mask) == kEnd_state;
}
inline WordBreakTable::Node
WordBreakTable::initialState() const
{
return kInitial_state;
}
#endif // _WDBKTBL
//eof