xref: /aosp_15_r20/external/icu/libicu/cts_headers/mlbe.h (revision 0e209d3975ff4a8c132096b14b0e9364a753506e)
1 // © 2022 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 
4 #ifndef MLBREAKENGINE_H
5 #define MLBREAKENGINE_H
6 
7 #include "hash.h"
8 #include "unicode/resbund.h"
9 #include "unicode/uniset.h"
10 #include "unicode/utext.h"
11 #include "uvectr32.h"
12 
13 U_NAMESPACE_BEGIN
14 
15 #if !UCONFIG_NO_BREAK_ITERATION
16 
17 /**
18  * A machine learning break engine for the phrase breaking in Japanese.
19  */
20 class MlBreakEngine : public UMemory {
21    public:
22     /**
23      * Constructor.
24      *
25      * @param digitOrOpenPunctuationOrAlphabetSet An UnicodeSet with the digit, open punctuation and
26      * alphabet.
27      * @param closePunctuationSet An UnicodeSet with close punctuation.
28      * @param status Information on any errors encountered.
29      */
30     MlBreakEngine(const UnicodeSet &digitOrOpenPunctuationOrAlphabetSet,
31                   const UnicodeSet &closePunctuationSet, UErrorCode &status);
32 
33     /**
34      * Virtual destructor.
35      */
36     virtual ~MlBreakEngine();
37 
38    public:
39     /**
40      * Divide up a range of characters handled by this break engine.
41      *
42      * @param inText A UText representing the text
43      * @param rangeStart The start of the range of the characters
44      * @param rangeEnd The end of the range of the characters
45      * @param foundBreaks Output of C array of int32_t break positions, or 0
46      * @param inString The normalized string of text ranging from rangeStart to rangeEnd
47      * @param inputMap The vector storing the native index of inText
48      * @param status Information on any errors encountered.
49      * @return The number of breaks found
50      */
51     int32_t divideUpRange(UText *inText, int32_t rangeStart, int32_t rangeEnd,
52                           UVector32 &foundBreaks, const UnicodeString &inString,
53                           const LocalPointer<UVector32> &inputMap, UErrorCode &status) const;
54 
55    private:
56     /**
57      * Load the machine learning's model file.
58      *
59      * @param error Information on any errors encountered.
60      */
61     void loadMLModel(UErrorCode &error);
62 
63     /**
64      * In the machine learning's model file, specify the name of the key and value to load the
65      * corresponding feature and its score.
66      *
67      * @param rb A ResouceBundle corresponding to the model file.
68      * @param keyName The kay name in the model file.
69      * @param valueName The value name in the model file.
70      * @param model A hashtable to store the pairs of the feature and its score.
71      * @param error Information on any errors encountered.
72      */
73     void initKeyValue(UResourceBundle *rb, const char *keyName, const char *valueName,
74                       Hashtable &model, UErrorCode &error);
75 
76     /**
77      * Initialize the index list from the input string.
78      *
79      * @param inString A input string to be segmented.
80      * @param indexList A code unit index list of inString.
81      * @param status Information on any errors encountered.
82      * @return The number of code units of the first four characters in inString.
83      */
84     int32_t initIndexList(const UnicodeString &inString, int32_t *indexList,
85                           UErrorCode &status) const;
86 
87     /**
88      * Evaluate whether the index is a potential breakpoint.
89      *
90      * @param inString A input string to be segmented.
91      * @param indexList A code unit index list of the inString.
92      * @param startIdx The start index of the indexList.
93      * @param numCodeUnits  The current code unit boundary of the indexList.
94      * @param numBreaks The accumulated number of breakpoints.
95      * @param boundary A vector including the index of the breakpoint.
96      * @param status Information on any errors encountered.
97      * @return The number of breakpoints
98      */
99     int32_t evaluateBreakpoint(const UnicodeString &inString, int32_t *indexList, int32_t startIdx,
100                                int32_t numCodeUnits, int32_t numBreaks, UVector32 &boundary,
101                                UErrorCode &status) const;
102 
103     void printUnicodeString(const UnicodeString &s) const;
104 
105     UnicodeSet fDigitOrOpenPunctuationOrAlphabetSet;
106     UnicodeSet fClosePunctuationSet;
107     Hashtable fModel[13];  // {UW1, UW2, ... UW6, BW1, ... BW3, TW1, TW2, ... TW4} 6+3+4= 13
108     int32_t fNegativeSum;
109 };
110 
111 #endif
112 
113 U_NAMESPACE_END
114 
115 /* MLBREAKENGINE_H */
116 #endif
117