1 /*

     2 **********************************************************************

     3 *   Copyright (C) 1999-2002, 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  *

    55  * @draft ICU 2.2

    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  * @draft ICU 2.2

    81  */

    82 U_CAPI UScriptRun * U_EXPORT2

    83 uscript_openRun(const UChar *src, int32_t length, UErrorCode *pErrorCode);

    84 

    85 /**

    86  * Frees the given <code>UScriptRun</code> object and any storage associated with it.

    87  * On return, scriptRun no longer points to a valid <code>UScriptRun</code> object.

    88  *

    89  * @param scriptRun is the <code>UScriptRun</code> object which will be freed.

    90  *

    91  * @draft ICU 2.2

    92  */

    93 U_CAPI void U_EXPORT2

    94 uscript_closeRun(UScriptRun *scriptRun);

    95 

    96 /**

    97  * Reset the <code>UScriptRun</code> object so that it will start iterating from

    98  * the beginning.

    99  *

   100  * @param scriptRun is the address of the <code>UScriptRun</code> object to be reset.

   101  *

   102  * @draft ICU 2.2

   103  */

   104 U_CAPI void U_EXPORT2

   105 uscript_resetRun(UScriptRun *scriptRun);

   106 

   107 /**

   108  * Change the text over which the given <code>UScriptRun</code> object iterates.

   109  *

   110  * @param scriptRun is the <code>UScriptRun</code> object which will be changed.

   111  *

   112  * @param src is the address of the new array of characters over which to iterate.

   113  *        If <code>src == NULL</code> and <code>length == 0</code>,

   114  *        the <code>UScriptRun</code> object will become empty.

   115  *

   116  * @param length is the new number of characters over which to iterate

   117  *

   118  * @param pErrorCode is a pointer to a valid <code>UErrorCode</code> value. If this value

   119  *        indicates a failure on entry, the function will immediately return.

   120  *        On exit the value will indicate the success of the operation.

   121  *

   122  * @draft ICU 2.2

   123  */

   124 U_CAPI void U_EXPORT2

   125 uscript_setRunText(UScriptRun *scriptRun, const UChar *src, int32_t length, UErrorCode *pErrorCode);

   126 

   127 /**

   128  * Advance the <code>UScriptRun</code> object to the next script run, return the start and limit

   129  * offsets, and the script of the run.

   130  *

   131  * @param scriptRun is the address of the <code>UScriptRun</code> object.

   132  *

   133  * @param pRunStart is a pointer to the variable to receive the starting offset of the next run.

   134  *        This pointer can be <code>NULL</code> if the value is not needed.

   135  *

   136  * @param pRunLimit is a pointer to the variable to receive the limit offset of the next run.

   137  *        This pointer can be <code>NULL</code> if the value is not needed.

   138  *

   139  * @param pRunScript is a pointer to the variable to receive the UScriptCode for the

   140  *        script of the current run. This pointer can be <code>NULL</code> if the value is not needed.

   141  *

   142  * @return true if there was another script run.

   143  *

   144  * @draft ICU 2.2

   145  */

   146 U_CAPI UBool U_EXPORT2

   147 uscript_nextRun(UScriptRun *scriptRun, int32_t *pRunStart, int32_t *pRunLimit, UScriptCode *pRunScript);

   148 

   149 #endif