1/*
2**********************************************************************
3*   Copyright (C) 1999-2011, International Business Machines
4*   Corporation and others.  All Rights Reserved.
5**********************************************************************
6*
7* File USC_IMPL.H
8*
9* Modification History:
10*
11*   Date        Name        Description
12*   07/08/2002  Eric Mader  Creation.
13******************************************************************************
14*/
15
16#ifndef USC_IMPL_H
17#define USC_IMPL_H
18#include "unicode/utypes.h"
19#include "unicode/uscript.h"
20
21/**
22 * <code>UScriptRun</code> is used to find runs of characters in
23 * the same script. It implements a simple iterator over an array
24 * of characters. The iterator will resolve script-neutral characters
25 * like punctuation into the script of the surrounding characters.
26 *
27 * The iterator will try to match paired punctuation. If it sees an
28 * opening punctuation character, it will remember the script that
29 * was assigned to that character, and assign the same script to the
30 * matching closing punctuation.
31 *
32 * Scripts are chosen based on the <code>UScriptCode</code> enumeration.
33 * No attempt is made to combine related scripts into a single run. In
34 * particular, Hiragana, Katakana, and Han characters will appear in seperate
35 * runs.
36
37 * Here is an example of how to iterate over script runs:
38 * <pre>
39 * \code
40 * void printScriptRuns(const UChar *text, int32_t length)
41 * {
42 *     UErrorCode error = U_ZERO_ERROR;
43 *     UScriptRun *scriptRun = uscript_openRun(text, testLength, &error);
44 *     int32_t start = 0, limit = 0;
45 *     UScriptCode code = USCRIPT_INVALID_CODE;
46 *
47 *     while (uscript_nextRun(&start, &limit, &code)) {
48 *         printf("Script '%s' from %d to %d.\n", uscript_getName(code), start, limit);
49 *     }
50 *
51 *     uscript_closeRun(scriptRun);
52 *  }
53 * </pre>
54 */
55struct UScriptRun;
56
57typedef struct UScriptRun UScriptRun;
58
59/**
60 * Create a <code>UScriptRun</code> object for iterating over the given text. This object must
61 * be freed using <code>uscript_closeRun()</code>. Note that this object does not copy the source text,
62 * only the pointer to it. You must make sure that the pointer remains valid until you call
63 * <code>uscript_closeRun()</code> or <code>uscript_setRunText()</code>.
64 *
65 * @param src is the address of the array of characters over which to iterate.
66 *        if <code>src == NULL</code> and <code>length == 0</code>,
67 *        an empty <code>UScriptRun</code> object will be returned.
68 *
69 * @param length is the number of characters over which to iterate.
70 *
71 * @param pErrorCode is a pointer to a valid <code>UErrorCode</code> value. If this value
72 *        indicates a failure on entry, the function will immediately return.
73 *        On exit the value will indicate the success of the operation.
74 *
75 * @return the address of <code>UScriptRun</code> object which will iterate over the text,
76 *         or <code>NULL</code> if the operation failed.
77 */
78U_CAPI UScriptRun * U_EXPORT2
79uscript_openRun(const UChar *src, int32_t length, UErrorCode *pErrorCode);
80
81/**
82 * Frees the given <code>UScriptRun</code> object and any storage associated with it.
83 * On return, scriptRun no longer points to a valid <code>UScriptRun</code> object.
84 *
85 * @param scriptRun is the <code>UScriptRun</code> object which will be freed.
86 */
87U_CAPI void U_EXPORT2
88uscript_closeRun(UScriptRun *scriptRun);
89
90/**
91 * Reset the <code>UScriptRun</code> object so that it will start iterating from
92 * the beginning.
93 *
94 * @param scriptRun is the address of the <code>UScriptRun</code> object to be reset.
95 */
96U_CAPI void U_EXPORT2
97uscript_resetRun(UScriptRun *scriptRun);
98
99/**
100 * Change the text over which the given <code>UScriptRun</code> object iterates.
101 *
102 * @param scriptRun is the <code>UScriptRun</code> object which will be changed.
103 *
104 * @param src is the address of the new array of characters over which to iterate.
105 *        If <code>src == NULL</code> and <code>length == 0</code>,
106 *        the <code>UScriptRun</code> object will become empty.
107 *
108 * @param length is the new number of characters over which to iterate
109 *
110 * @param pErrorCode is a pointer to a valid <code>UErrorCode</code> value. If this value
111 *        indicates a failure on entry, the function will immediately return.
112 *        On exit the value will indicate the success of the operation.
113 */
114U_CAPI void U_EXPORT2
115uscript_setRunText(UScriptRun *scriptRun, const UChar *src, int32_t length, UErrorCode *pErrorCode);
116
117/**
118 * Advance the <code>UScriptRun</code> object to the next script run, return the start and limit
119 * offsets, and the script of the run.
120 *
121 * @param scriptRun is the address of the <code>UScriptRun</code> object.
122 *
123 * @param pRunStart is a pointer to the variable to receive the starting offset of the next run.
124 *        This pointer can be <code>NULL</code> if the value is not needed.
125 *
126 * @param pRunLimit is a pointer to the variable to receive the limit offset of the next run.
127 *        This pointer can be <code>NULL</code> if the value is not needed.
128 *
129 * @param pRunScript is a pointer to the variable to receive the UScriptCode for the
130 *        script of the current run. This pointer can be <code>NULL</code> if the value is not needed.
131 *
132 * @return true if there was another script run.
133 */
134U_CAPI UBool U_EXPORT2
135uscript_nextRun(UScriptRun *scriptRun, int32_t *pRunStart, int32_t *pRunLimit, UScriptCode *pRunScript);
136
137#endif
138