Victor Chang | 7322950 | 2020-09-17 13:39:19 +0100 | [diff] [blame] | 1 | // © 2016 and later: Unicode, Inc. and others. |
| 2 | // License & terms of use: http://www.unicode.org/copyright.html |
| 3 | /* |
| 4 | ********************************************************************** |
| 5 | * Copyright (C) 1999-2011, International Business Machines |
| 6 | * Corporation and others. All Rights Reserved. |
| 7 | ********************************************************************** |
| 8 | * |
| 9 | * File USC_IMPL.H |
| 10 | * |
| 11 | * Modification History: |
| 12 | * |
| 13 | * Date Name Description |
| 14 | * 07/08/2002 Eric Mader Creation. |
| 15 | ****************************************************************************** |
| 16 | */ |
| 17 | |
| 18 | #ifndef USC_IMPL_H |
| 19 | #define USC_IMPL_H |
| 20 | #include "unicode/utypes.h" |
| 21 | #include "unicode/uscript.h" |
| 22 | |
| 23 | /** |
| 24 | * <code>UScriptRun</code> is used to find runs of characters in |
| 25 | * the same script. It implements a simple iterator over an array |
| 26 | * of characters. The iterator will resolve script-neutral characters |
| 27 | * like punctuation into the script of the surrounding characters. |
| 28 | * |
| 29 | * The iterator will try to match paired punctuation. If it sees an |
| 30 | * opening punctuation character, it will remember the script that |
| 31 | * was assigned to that character, and assign the same script to the |
| 32 | * matching closing punctuation. |
| 33 | * |
| 34 | * Scripts are chosen based on the <code>UScriptCode</code> enumeration. |
| 35 | * No attempt is made to combine related scripts into a single run. In |
| 36 | * particular, Hiragana, Katakana, and Han characters will appear in seperate |
| 37 | * runs. |
| 38 | |
| 39 | * Here is an example of how to iterate over script runs: |
| 40 | * <pre> |
| 41 | * \code |
| 42 | * void printScriptRuns(const UChar *text, int32_t length) |
| 43 | * { |
| 44 | * UErrorCode error = U_ZERO_ERROR; |
| 45 | * UScriptRun *scriptRun = uscript_openRun(text, testLength, &error); |
| 46 | * int32_t start = 0, limit = 0; |
| 47 | * UScriptCode code = USCRIPT_INVALID_CODE; |
| 48 | * |
| 49 | * while (uscript_nextRun(&start, &limit, &code)) { |
| 50 | * printf("Script '%s' from %d to %d.\n", uscript_getName(code), start, limit); |
| 51 | * } |
| 52 | * |
| 53 | * uscript_closeRun(scriptRun); |
| 54 | * } |
| 55 | * </pre> |
| 56 | */ |
| 57 | struct UScriptRun; |
| 58 | |
| 59 | typedef struct UScriptRun UScriptRun; |
| 60 | |
| 61 | /** |
| 62 | * Create a <code>UScriptRun</code> object for iterating over the given text. This object must |
| 63 | * be freed using <code>uscript_closeRun()</code>. Note that this object does not copy the source text, |
| 64 | * only the pointer to it. You must make sure that the pointer remains valid until you call |
| 65 | * <code>uscript_closeRun()</code> or <code>uscript_setRunText()</code>. |
| 66 | * |
| 67 | * @param src is the address of the array of characters over which to iterate. |
| 68 | * if <code>src == NULL</code> and <code>length == 0</code>, |
| 69 | * an empty <code>UScriptRun</code> object will be returned. |
| 70 | * |
| 71 | * @param length is the number of characters over which to iterate. |
| 72 | * |
| 73 | * @param pErrorCode is a pointer to a valid <code>UErrorCode</code> value. If this value |
| 74 | * indicates a failure on entry, the function will immediately return. |
| 75 | * On exit the value will indicate the success of the operation. |
| 76 | * |
| 77 | * @return the address of <code>UScriptRun</code> object which will iterate over the text, |
| 78 | * or <code>NULL</code> if the operation failed. |
| 79 | */ |
| 80 | U_CAPI UScriptRun * U_EXPORT2 |
| 81 | uscript_openRun(const UChar *src, int32_t length, UErrorCode *pErrorCode); |
| 82 | |
| 83 | /** |
| 84 | * Frees the given <code>UScriptRun</code> object and any storage associated with it. |
| 85 | * On return, scriptRun no longer points to a valid <code>UScriptRun</code> object. |
| 86 | * |
| 87 | * @param scriptRun is the <code>UScriptRun</code> object which will be freed. |
| 88 | */ |
| 89 | U_CAPI void U_EXPORT2 |
| 90 | uscript_closeRun(UScriptRun *scriptRun); |
| 91 | |
| 92 | /** |
| 93 | * Reset the <code>UScriptRun</code> object so that it will start iterating from |
| 94 | * the beginning. |
| 95 | * |
| 96 | * @param scriptRun is the address of the <code>UScriptRun</code> object to be reset. |
| 97 | */ |
| 98 | U_CAPI void U_EXPORT2 |
| 99 | uscript_resetRun(UScriptRun *scriptRun); |
| 100 | |
| 101 | /** |
| 102 | * Change the text over which the given <code>UScriptRun</code> object iterates. |
| 103 | * |
| 104 | * @param scriptRun is the <code>UScriptRun</code> object which will be changed. |
| 105 | * |
| 106 | * @param src is the address of the new array of characters over which to iterate. |
| 107 | * If <code>src == NULL</code> and <code>length == 0</code>, |
| 108 | * the <code>UScriptRun</code> object will become empty. |
| 109 | * |
| 110 | * @param length is the new number of characters over which to iterate |
| 111 | * |
| 112 | * @param pErrorCode is a pointer to a valid <code>UErrorCode</code> value. If this value |
| 113 | * indicates a failure on entry, the function will immediately return. |
| 114 | * On exit the value will indicate the success of the operation. |
| 115 | */ |
| 116 | U_CAPI void U_EXPORT2 |
| 117 | uscript_setRunText(UScriptRun *scriptRun, const UChar *src, int32_t length, UErrorCode *pErrorCode); |
| 118 | |
| 119 | /** |
| 120 | * Advance the <code>UScriptRun</code> object to the next script run, return the start and limit |
| 121 | * offsets, and the script of the run. |
| 122 | * |
| 123 | * @param scriptRun is the address of the <code>UScriptRun</code> object. |
| 124 | * |
| 125 | * @param pRunStart is a pointer to the variable to receive the starting offset of the next run. |
| 126 | * This pointer can be <code>NULL</code> if the value is not needed. |
| 127 | * |
| 128 | * @param pRunLimit is a pointer to the variable to receive the limit offset of the next run. |
| 129 | * This pointer can be <code>NULL</code> if the value is not needed. |
| 130 | * |
| 131 | * @param pRunScript is a pointer to the variable to receive the UScriptCode for the |
| 132 | * script of the current run. This pointer can be <code>NULL</code> if the value is not needed. |
| 133 | * |
| 134 | * @return true if there was another script run. |
| 135 | */ |
| 136 | U_CAPI UBool U_EXPORT2 |
| 137 | uscript_nextRun(UScriptRun *scriptRun, int32_t *pRunStart, int32_t *pRunLimit, UScriptCode *pRunScript); |
| 138 | |
| 139 | #endif |