/*

**********************************************************************

*   Copyright (C) 1999-2002, International Business Machines

*   Corporation and others.  All Rights Reserved.

**********************************************************************

*

* File USC_IMPL.H

*

* Modification History:

*

*   Date        Name        Description

*   07/08/2002  Eric Mader  Creation.

******************************************************************************

*/

#ifndef USC_IMPL_H

#define USC_IMPL_H

#include "unicode/utypes.h"

#include "unicode/uscript.h"

/**

 * <code>UScriptRun</code> is used to find runs of characters in

 * the same script. It implements a simple iterator over an array

 * of characters. The iterator will resolve script-neutral characters

 * like punctuation into the script of the surrounding characters.

 *

 * The iterator will try to match paired punctuation. If it sees an

 * opening punctuation character, it will remember the script that

 * was assigned to that character, and assign the same script to the

 * matching closing punctuation.

 *

 * Scripts are chosen based on the <code>UScriptCode</code> enumeration.

 * No attempt is made to combine related scripts into a single run. In

 * particular, Hiragana, Katakana, and Han characters will appear in seperate

 * runs.

 * Here is an example of how to iterate over script runs:

 * <pre>

 * \code

 * void printScriptRuns(const UChar *text, int32_t length)

 * {

 *     UErrorCode error = U_ZERO_ERROR;

 *     UScriptRun *scriptRun = uscript_openRun(text, testLength, &error);

 *     int32_t start = 0, limit = 0;

 *     UScriptCode code = USCRIPT_INVALID_CODE;

 *

 *     while (uscript_nextRun(&start, &limit, &code)) {

 *         printf("Script '%s' from %d to %d.\n", uscript_getName(code), start, limit);

 *     }

 *

 *     uscript_closeRun(scriptRun);

 *  }

 * </pre>

 *

 * @draft ICU 2.2

 */

struct UScriptRun;

typedef struct UScriptRun UScriptRun;

/**

 * Create a <code>UScriptRun</code> object for iterating over the given text. This object must

 * be freed using <code>uscript_closeRun()</code>. Note that this object does not copy the source text,

 * only the pointer to it. You must make sure that the pointer remains valid until you call

 * <code>uscript_closeRun()</code> or <code>uscript_setRunText()</code>.

 *

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

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

 *        an empty <code>UScriptRun</code> object will be returned.

 *

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

 *

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

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

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

 *

 * @return the address of <code>UScriptRun</code> object which will iterate over the text,

 *         or <code>NULL</code> if the operation failed.

 *

 * @draft ICU 2.2

 */

U_CAPI UScriptRun * U_EXPORT2

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

/**

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

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

 *

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

 *

 * @draft ICU 2.2

 */

U_CAPI void U_EXPORT2

uscript_closeRun(UScriptRun *scriptRun);

/**

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

 * the beginning.

 *

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

 *

 * @draft ICU 2.2

 */

U_CAPI void U_EXPORT2

uscript_resetRun(UScriptRun *scriptRun);

/**

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

 *

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

 *

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

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

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

 *

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

 *

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

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

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

 *

 * @draft ICU 2.2

 */

U_CAPI void U_EXPORT2

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

/**

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

 * offsets, and the script of the run.

 *

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

 *

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

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

 *

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

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

 *

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

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

 *

 * @return true if there was another script run.

 *

 * @draft ICU 2.2

 */

U_CAPI UBool U_EXPORT2

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

#endif