Check in the pristine copy of ICU 4.6...

icu46/source/i18n/unicode/utrans.h

+/*
+*******************************************************************************
+*   Copyright (C) 1997-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*******************************************************************************
+*   Date        Name        Description
+*   06/21/00    aliu        Creation.
+*******************************************************************************
+*/
+
+#ifndef UTRANS_H
+#define UTRANS_H
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_TRANSLITERATION
+
+#include "unicode/localpointer.h"
+#include "unicode/urep.h"
+#include "unicode/parseerr.h"
+#include "unicode/uenum.h"
+
+/********************************************************************
+ * General Notes
+ ********************************************************************
+ */
+/**
+ * \file
+ * \brief C API: Transliterator
+ *
+ * <h2> Transliteration </h2>
+ * The data structures and functions described in this header provide
+ * transliteration services.  Transliteration services are implemented
+ * as C++ classes.  The comments and documentation in this header
+ * assume the reader is familiar with the C++ headers translit.h and
+ * associated documentation.
+ *
+ * A significant but incomplete subset of the C++ transliteration
+ * services are available to C code through this header.  In order to
+ * access more complex transliteration services, refer to the C++
+ * headers and documentation.
+ *
+ * There are two sets of functions for working with transliterator IDs:
+ *
+ * An old, deprecated set uses char * IDs, which works for true and pure
+ * identifiers that these APIs were designed for,
+ * for example "Cyrillic-Latin".
+ * It does not work when the ID contains filters ("[:Script=Cyrl:]")
+ * or even a complete set of rules because then the ID string contains more
+ * than just "invariant" characters (see utypes.h).
+ *
+ * A new set of functions replaces the old ones and uses UChar * IDs,
+ * paralleling the UnicodeString IDs in the C++ API. (New in ICU 2.8.)
+ */
+
+/********************************************************************
+ * Data Structures
+ ********************************************************************/
+
+/**
+ * An opaque transliterator for use in C.  Open with utrans_openxxx()
+ * and close with utrans_close() when done.  Equivalent to the C++ class
+ * Transliterator and its subclasses.
+ * @see Transliterator
+ * @stable ICU 2.0
+ */
+typedef void* UTransliterator;
+
+/**
+ * Direction constant indicating the direction in a transliterator,
+ * e.g., the forward or reverse rules of a RuleBasedTransliterator.
+ * Specified when a transliterator is opened.  An "A-B" transliterator
+ * transliterates A to B when operating in the forward direction, and
+ * B to A when operating in the reverse direction.
+ * @stable ICU 2.0
+ */
+typedef enum UTransDirection {
+    
+    /**
+     * UTRANS_FORWARD means from &lt;source&gt; to &lt;target&gt; for a
+     * transliterator with ID &lt;source&gt;-&lt;target&gt;.  For a transliterator
+     * opened using a rule, it means forward direction rules, e.g.,
+     * "A > B".
+     */
+    UTRANS_FORWARD,
+
+    /**
+     * UTRANS_REVERSE means from &lt;target&gt; to &lt;source&gt; for a
+     * transliterator with ID &lt;source&gt;-&lt;target&gt;.  For a transliterator
+     * opened using a rule, it means reverse direction rules, e.g.,
+     * "A < B".
+     */
+    UTRANS_REVERSE
+
+} UTransDirection;
+
+/**
+ * Position structure for utrans_transIncremental() incremental
+ * transliteration.  This structure defines two substrings of the text
+ * being transliterated.  The first region, [contextStart,
+ * contextLimit), defines what characters the transliterator will read
+ * as context.  The second region, [start, limit), defines what
+ * characters will actually be transliterated.  The second region
+ * should be a subset of the first.
+ *
+ * <p>After a transliteration operation, some of the indices in this
+ * structure will be modified.  See the field descriptions for
+ * details.
+ *
+ * <p>contextStart <= start <= limit <= contextLimit
+ *
+ * <p>Note: All index values in this structure must be at code point
+ * boundaries.  That is, none of them may occur between two code units
+ * of a surrogate pair.  If any index does split a surrogate pair,
+ * results are unspecified.
+ *
+ * @stable ICU 2.0
+ */
+typedef struct UTransPosition {
+
+    /**
+     * Beginning index, inclusive, of the context to be considered for
+     * a transliteration operation.  The transliterator will ignore
+     * anything before this index.  INPUT/OUTPUT parameter: This parameter
+     * is updated by a transliteration operation to reflect the maximum
+     * amount of antecontext needed by a transliterator.
+     * @stable ICU 2.4
+     */
+    int32_t contextStart;
+    
+    /**
+     * Ending index, exclusive, of the context to be considered for a
+     * transliteration operation.  The transliterator will ignore
+     * anything at or after this index.  INPUT/OUTPUT parameter: This
+     * parameter is updated to reflect changes in the length of the
+     * text, but points to the same logical position in the text.
+     * @stable ICU 2.4
+     */
+    int32_t contextLimit;
+    
+    /**
+     * Beginning index, inclusive, of the text to be transliteratd.
+     * INPUT/OUTPUT parameter: This parameter is advanced past
+     * characters that have already been transliterated by a
+     * transliteration operation.
+     * @stable ICU 2.4
+     */
+    int32_t start;
+    
+    /**
+     * Ending index, exclusive, of the text to be transliteratd.
+     * INPUT/OUTPUT parameter: This parameter is updated to reflect
+     * changes in the length of the text, but points to the same
+     * logical position in the text.
+     * @stable ICU 2.4
+     */
+    int32_t limit;
+
+} UTransPosition;
+
+/********************************************************************
+ * General API
+ ********************************************************************/
+
+/**
+ * Open a custom transliterator, given a custom rules string 
+ * OR 
+ * a system transliterator, given its ID.  
+ * Any non-NULL result from this function should later be closed with
+ * utrans_close().
+ *
+ * @param id a valid transliterator ID
+ * @param idLength the length of the ID string, or -1 if NUL-terminated
+ * @param dir the desired direction
+ * @param rules the transliterator rules.  See the C++ header rbt.h for
+ *              rules syntax. If NULL then a system transliterator matching
+ *              the ID is returned.
+ * @param rulesLength the length of the rules, or -1 if the rules
+ *                    are NUL-terminated.
+ * @param parseError a pointer to a UParseError struct to receive the details
+ *                   of any parsing errors. This parameter may be NULL if no
+ *                   parsing error details are desired.
+ * @param pErrorCode a pointer to the UErrorCode
+ * @return a transliterator pointer that may be passed to other
+ *         utrans_xxx() functions, or NULL if the open call fails.
+ * @stable ICU 2.8
+ */
+U_STABLE UTransliterator* U_EXPORT2
+utrans_openU(const UChar *id,
+             int32_t idLength,
+             UTransDirection dir,
+             const UChar *rules,
+             int32_t rulesLength,
+             UParseError *parseError,
+             UErrorCode *pErrorCode);
+
+/**
+ * Open an inverse of an existing transliterator.  For this to work,
+ * the inverse must be registered with the system.  For example, if
+ * the Transliterator "A-B" is opened, and then its inverse is opened,
+ * the result is the Transliterator "B-A", if such a transliterator is
+ * registered with the system.  Otherwise the result is NULL and a
+ * failing UErrorCode is set.  Any non-NULL result from this function
+ * should later be closed with utrans_close().
+ *
+ * @param trans the transliterator to open the inverse of.
+ * @param status a pointer to the UErrorCode
+ * @return a pointer to a newly-opened transliterator that is the
+ * inverse of trans, or NULL if the open call fails.
+ * @stable ICU 2.0
+ */
+U_STABLE UTransliterator* U_EXPORT2 
+utrans_openInverse(const UTransliterator* trans,
+                   UErrorCode* status);
+
+/**
+ * Create a copy of a transliterator.  Any non-NULL result from this
+ * function should later be closed with utrans_close().
+ *
+ * @param trans the transliterator to be copied.
+ * @param status a pointer to the UErrorCode
+ * @return a transliterator pointer that may be passed to other
+ * utrans_xxx() functions, or NULL if the clone call fails.
+ * @stable ICU 2.0
+ */
+U_STABLE UTransliterator* U_EXPORT2 
+utrans_clone(const UTransliterator* trans,
+             UErrorCode* status);
+
+/**
+ * Close a transliterator.  Any non-NULL pointer returned by
+ * utrans_openXxx() or utrans_clone() should eventually be closed.
+ * @param trans the transliterator to be closed.
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+utrans_close(UTransliterator* trans);
+
+#if U_SHOW_CPLUSPLUS_API
+
+U_NAMESPACE_BEGIN
+
+/**
+ * \class LocalUTransliteratorPointer
+ * "Smart pointer" class, closes a UTransliterator via utrans_close().
+ * For most methods see the LocalPointerBase base class.
+ *
+ * @see LocalPointerBase
+ * @see LocalPointer
+ * @stable ICU 4.4
+ */
+U_DEFINE_LOCAL_OPEN_POINTER(LocalUTransliteratorPointer, UTransliterator, utrans_close);
+
+U_NAMESPACE_END
+
+#endif
+
+/**
+ * Return the programmatic identifier for this transliterator.
+ * If this identifier is passed to utrans_openU(), it will open
+ * a transliterator equivalent to this one, if the ID has been
+ * registered.
+ *
+ * @param trans the transliterator to return the ID of.
+ * @param resultLength pointer to an output variable receiving the length
+ *        of the ID string; can be NULL
+ * @return the NUL-terminated ID string. This pointer remains
+ * valid until utrans_close() is called on this transliterator.
+ *
+ * @stable ICU 2.8
+ */
+U_STABLE const UChar * U_EXPORT2
+utrans_getUnicodeID(const UTransliterator *trans,
+                    int32_t *resultLength);
+
+/**
+ * Register an open transliterator with the system.  When
+ * utrans_open() is called with an ID string that is equal to that
+ * returned by utrans_getID(adoptedTrans,...), then
+ * utrans_clone(adoptedTrans,...) is returned.
+ *
+ * <p>NOTE: After this call the system owns the adoptedTrans and will
+ * close it.  The user must not call utrans_close() on adoptedTrans.
+ *
+ * @param adoptedTrans a transliterator, typically the result of
+ * utrans_openRules(), to be registered with the system.
+ * @param status a pointer to the UErrorCode
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+utrans_register(UTransliterator* adoptedTrans,
+                UErrorCode* status);
+
+/**
+ * Unregister a transliterator from the system.  After this call the
+ * system will no longer recognize the given ID when passed to
+ * utrans_open(). If the ID is invalid then nothing is done.
+ *
+ * @param id an ID to unregister
+ * @param idLength the length of id, or -1 if id is zero-terminated
+ * @stable ICU 2.8
+ */
+U_STABLE void U_EXPORT2
+utrans_unregisterID(const UChar* id, int32_t idLength);
+
+/**
+ * Set the filter used by a transliterator.  A filter can be used to
+ * make the transliterator pass certain characters through untouched.
+ * The filter is expressed using a UnicodeSet pattern.  If the
+ * filterPattern is NULL or the empty string, then the transliterator
+ * will be reset to use no filter.
+ *
+ * @param trans the transliterator
+ * @param filterPattern a pattern string, in the form accepted by
+ * UnicodeSet, specifying which characters to apply the
+ * transliteration to.  May be NULL or the empty string to indicate no
+ * filter.
+ * @param filterPatternLen the length of filterPattern, or -1 if
+ * filterPattern is zero-terminated
+ * @param status a pointer to the UErrorCode
+ * @see UnicodeSet
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+utrans_setFilter(UTransliterator* trans,
+                 const UChar* filterPattern,
+                 int32_t filterPatternLen,
+                 UErrorCode* status);
+
+/**
+ * Return the number of system transliterators.
+ * It is recommended to use utrans_openIDs() instead.
+ *
+ * @return the number of system transliterators.
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2 
+utrans_countAvailableIDs(void);
+
+/**
+ * Return a UEnumeration for the available transliterators.
+ *
+ * @param pErrorCode Pointer to the UErrorCode in/out parameter.
+ * @return UEnumeration for the available transliterators.
+ *         Close with uenum_close().
+ *
+ * @stable ICU 2.8
+ */
+U_STABLE UEnumeration * U_EXPORT2
+utrans_openIDs(UErrorCode *pErrorCode);
+
+/********************************************************************
+ * Transliteration API
+ ********************************************************************/
+
+/**
+ * Transliterate a segment of a UReplaceable string.  The string is
+ * passed in as a UReplaceable pointer rep and a UReplaceableCallbacks
+ * function pointer struct repFunc.  Functions in the repFunc struct
+ * will be called in order to modify the rep string.
+ *
+ * @param trans the transliterator
+ * @param rep a pointer to the string.  This will be passed to the
+ * repFunc functions.
+ * @param repFunc a set of function pointers that will be used to
+ * modify the string pointed to by rep.
+ * @param start the beginning index, inclusive; <code>0 <= start <=
+ * limit</code>.
+ * @param limit pointer to the ending index, exclusive; <code>start <=
+ * limit <= repFunc->length(rep)</code>.  Upon return, *limit will
+ * contain the new limit index.  The text previously occupying
+ * <code>[start, limit)</code> has been transliterated, possibly to a
+ * string of a different length, at <code>[start,
+ * </code><em>new-limit</em><code>)</code>, where <em>new-limit</em>
+ * is the return value.
+ * @param status a pointer to the UErrorCode
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+utrans_trans(const UTransliterator* trans,
+             UReplaceable* rep,
+             UReplaceableCallbacks* repFunc,
+             int32_t start,
+             int32_t* limit,
+             UErrorCode* status);
+
+/**
+ * Transliterate the portion of the UReplaceable text buffer that can
+ * be transliterated unambiguosly.  This method is typically called
+ * after new text has been inserted, e.g. as a result of a keyboard
+ * event.  The transliterator will try to transliterate characters of
+ * <code>rep</code> between <code>index.cursor</code> and
+ * <code>index.limit</code>.  Characters before
+ * <code>index.cursor</code> will not be changed.
+ *
+ * <p>Upon return, values in <code>index</code> will be updated.
+ * <code>index.start</code> will be advanced to the first
+ * character that future calls to this method will read.
+ * <code>index.cursor</code> and <code>index.limit</code> will
+ * be adjusted to delimit the range of text that future calls to
+ * this method may change.
+ *
+ * <p>Typical usage of this method begins with an initial call
+ * with <code>index.start</code> and <code>index.limit</code>
+ * set to indicate the portion of <code>text</code> to be
+ * transliterated, and <code>index.cursor == index.start</code>.
+ * Thereafter, <code>index</code> can be used without
+ * modification in future calls, provided that all changes to
+ * <code>text</code> are made via this method.
+ *
+ * <p>This method assumes that future calls may be made that will
+ * insert new text into the buffer.  As a result, it only performs
+ * unambiguous transliterations.  After the last call to this method,
+ * there may be untransliterated text that is waiting for more input
+ * to resolve an ambiguity.  In order to perform these pending
+ * transliterations, clients should call utrans_trans() with a start
+ * of index.start and a limit of index.end after the last call to this
+ * method has been made.
+ *
+ * @param trans the transliterator
+ * @param rep a pointer to the string.  This will be passed to the
+ * repFunc functions.
+ * @param repFunc a set of function pointers that will be used to
+ * modify the string pointed to by rep.
+ * @param pos a struct containing the start and limit indices of the
+ * text to be read and the text to be transliterated
+ * @param status a pointer to the UErrorCode
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+utrans_transIncremental(const UTransliterator* trans,
+                        UReplaceable* rep,
+                        UReplaceableCallbacks* repFunc,
+                        UTransPosition* pos,
+                        UErrorCode* status);
+
+/**
+ * Transliterate a segment of a UChar* string.  The string is passed
+ * in in a UChar* buffer.  The string is modified in place.  If the
+ * result is longer than textCapacity, it is truncated.  The actual
+ * length of the result is returned in *textLength, if textLength is
+ * non-NULL. *textLength may be greater than textCapacity, but only
+ * textCapacity UChars will be written to *text, including the zero
+ * terminator.
+ *
+ * @param trans the transliterator
+ * @param text a pointer to a buffer containing the text to be
+ * transliterated on input and the result text on output.
+ * @param textLength a pointer to the length of the string in text.
+ * If the length is -1 then the string is assumed to be
+ * zero-terminated.  Upon return, the new length is stored in
+ * *textLength.  If textLength is NULL then the string is assumed to
+ * be zero-terminated.
+ * @param textCapacity a pointer to the length of the text buffer.
+ * Upon return, 
+ * @param start the beginning index, inclusive; <code>0 <= start <=
+ * limit</code>.
+ * @param limit pointer to the ending index, exclusive; <code>start <=
+ * limit <= repFunc->length(rep)</code>.  Upon return, *limit will
+ * contain the new limit index.  The text previously occupying
+ * <code>[start, limit)</code> has been transliterated, possibly to a
+ * string of a different length, at <code>[start,
+ * </code><em>new-limit</em><code>)</code>, where <em>new-limit</em>
+ * is the return value.
+ * @param status a pointer to the UErrorCode
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+utrans_transUChars(const UTransliterator* trans,
+                   UChar* text,
+                   int32_t* textLength,
+                   int32_t textCapacity,
+                   int32_t start,
+                   int32_t* limit,
+                   UErrorCode* status);
+
+/**
+ * Transliterate the portion of the UChar* text buffer that can be
+ * transliterated unambiguosly.  See utrans_transIncremental().  The
+ * string is passed in in a UChar* buffer.  The string is modified in
+ * place.  If the result is longer than textCapacity, it is truncated.
+ * The actual length of the result is returned in *textLength, if
+ * textLength is non-NULL. *textLength may be greater than
+ * textCapacity, but only textCapacity UChars will be written to
+ * *text, including the zero terminator.  See utrans_transIncremental()
+ * for usage details.
+ *
+ * @param trans the transliterator
+ * @param text a pointer to a buffer containing the text to be
+ * transliterated on input and the result text on output.
+ * @param textLength a pointer to the length of the string in text.
+ * If the length is -1 then the string is assumed to be
+ * zero-terminated.  Upon return, the new length is stored in
+ * *textLength.  If textLength is NULL then the string is assumed to
+ * be zero-terminated.
+ * @param textCapacity the length of the text buffer
+ * @param pos a struct containing the start and limit indices of the
+ * text to be read and the text to be transliterated
+ * @param status a pointer to the UErrorCode
+ * @see utrans_transIncremental
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+utrans_transIncrementalUChars(const UTransliterator* trans,
+                              UChar* text,
+                              int32_t* textLength,
+                              int32_t textCapacity,
+                              UTransPosition* pos,
+                              UErrorCode* status);
+
+/* deprecated API ----------------------------------------------------------- */
+
+/* see utrans.h documentation for why these functions are deprecated */
+
+/**
+ * Deprecated, use utrans_openU() instead.
+ * Open a custom transliterator, given a custom rules string 
+ * OR 
+ * a system transliterator, given its ID.  
+ * Any non-NULL result from this function should later be closed with
+ * utrans_close().
+ *
+ * @param id a valid ID, as returned by utrans_getAvailableID()
+ * @param dir the desired direction
+ * @param rules the transliterator rules.  See the C++ header rbt.h
+ * for rules syntax. If NULL then a system transliterator matching 
+ * the ID is returned.
+ * @param rulesLength the length of the rules, or -1 if the rules
+ * are zero-terminated.
+ * @param parseError a pointer to a UParseError struct to receive the
+ * details of any parsing errors. This parameter may be NULL if no
+ * parsing error details are desired.
+ * @param status a pointer to the UErrorCode
+ * @return a transliterator pointer that may be passed to other
+ * utrans_xxx() functions, or NULL if the open call fails.
+ * @deprecated ICU 2.8 Use utrans_openU() instead, see utrans.h
+ */
+U_DEPRECATED UTransliterator* U_EXPORT2 
+utrans_open(const char* id,
+            UTransDirection dir,
+            const UChar* rules,         /* may be Null */
+            int32_t rulesLength,        /* -1 if null-terminated */ 
+            UParseError* parseError,    /* may be Null */
+            UErrorCode* status);
+
+/**
+ * Deprecated, use utrans_getUnicodeID() instead.
+ * Return the programmatic identifier for this transliterator.
+ * If this identifier is passed to utrans_open(), it will open
+ * a transliterator equivalent to this one, if the ID has been
+ * registered.
+ * @param trans the transliterator to return the ID of.
+ * @param buf the buffer in which to receive the ID.  This may be
+ * NULL, in which case no characters are copied.
+ * @param bufCapacity the capacity of the buffer.  Ignored if buf is
+ * NULL.
+ * @return the actual length of the ID, not including
+ * zero-termination.  This may be greater than bufCapacity.
+ * @deprecated ICU 2.8 Use utrans_getUnicodeID() instead, see utrans.h
+ */
+U_DEPRECATED int32_t U_EXPORT2 
+utrans_getID(const UTransliterator* trans,
+             char* buf,
+             int32_t bufCapacity);
+
+/**
+ * Deprecated, use utrans_unregisterID() instead.
+ * Unregister a transliterator from the system.  After this call the
+ * system will no longer recognize the given ID when passed to
+ * utrans_open().  If the id is invalid then nothing is done.
+ *
+ * @param id a zero-terminated ID
+ * @deprecated ICU 2.8 Use utrans_unregisterID() instead, see utrans.h
+ */
+U_DEPRECATED void U_EXPORT2 
+utrans_unregister(const char* id);
+
+/**
+ * Deprecated, use utrans_openIDs() instead.
+ * Return the ID of the index-th system transliterator.  The result
+ * is placed in the given buffer.  If the given buffer is too small,
+ * the initial substring is copied to buf.  The result in buf is
+ * always zero-terminated.
+ *
+ * @param index the number of the transliterator to return.  Must
+ * satisfy 0 <= index < utrans_countAvailableIDs().  If index is out
+ * of range then it is treated as if it were 0.
+ * @param buf the buffer in which to receive the ID.  This may be
+ * NULL, in which case no characters are copied.
+ * @param bufCapacity the capacity of the buffer.  Ignored if buf is
+ * NULL.
+ * @return the actual length of the index-th ID, not including
+ * zero-termination.  This may be greater than bufCapacity.
+ * @deprecated ICU 2.8 Use utrans_openIDs() instead, see utrans.h
+ */
+U_DEPRECATED int32_t U_EXPORT2 
+utrans_getAvailableID(int32_t index,
+                      char* buf,
+                      int32_t bufCapacity);
+
+#endif /* #if !UCONFIG_NO_TRANSLITERATION */
+
+#endif