common/ucase.h

/*
*******************************************************************************
*
*   Copyright (C) 2004-2007, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
*******************************************************************************
*   file name:  ucase.h
*   encoding:   US-ASCII
*   tab size:   8 (not used)
*   indentation:4
*
*   created on: 2004aug30
*   created by: Markus W. Scherer
*
*   Low-level Unicode character/string case mapping code.
*/

#ifndef __UCASE_H__
#define __UCASE_H__

#include "unicode/utypes.h"
#include "unicode/uset.h"
#include "uset_imp.h"
#include "udataswp.h"

U_CDECL_BEGIN

/* library API -------------------------------------------------------------- */

struct UCaseProps;
typedef struct UCaseProps UCaseProps;

U_CAPI UCaseProps * U_EXPORT2
ucase_open(UErrorCode *pErrorCode);

U_CAPI UCaseProps * U_EXPORT2
ucase_openBinary(const uint8_t *bin, int32_t length, UErrorCode *pErrorCode);

U_CAPI void U_EXPORT2
ucase_close(UCaseProps *csp);


U_CAPI const UCaseProps * U_EXPORT2
ucase_getSingleton(UErrorCode *pErrorCode);

/**
 * Get a singleton dummy object, one that works with no real data.
 * This can be used when the real data is not available.
 * Using the dummy can reduce checks for available data after an initial failure.
 */
U_CAPI const UCaseProps * U_EXPORT2
ucase_getDummy(UErrorCode *pErrorCode);


U_CAPI int32_t U_EXPORT2
ucase_swap(const UDataSwapper *ds,
           const void *inData, int32_t length, void *outData,
           UErrorCode *pErrorCode);

U_CFUNC void U_EXPORT2
ucase_addPropertyStarts(const UCaseProps *csp, const USetAdder *sa, UErrorCode *pErrorCode);

/**
 * Requires non-NULL locale ID but otherwise does the equivalent of
 * checking for language codes as if uloc_getLanguage() were called:
 * Accepts both 2- and 3-letter codes and accepts case variants.
 */
U_CFUNC int32_t
ucase_getCaseLocale(const char *locale, int32_t *locCache);

/**
 * Bit mask for getting just the options from a string compare options word
 * that are relevant for case-insensitive string comparison.
 * See uchar.h. Also include _STRNCMP_STYLE and U_COMPARE_CODE_POINT_ORDER.
 * @internal
 */
#define _STRCASECMP_OPTIONS_MASK 0xffff

/**
 * Bit mask for getting just the options from a string compare options word
 * that are relevant for case folding (of a single string or code point).
 * See uchar.h.
 * @internal
 */
#define _FOLD_CASE_OPTIONS_MASK 0xff

/* single-code point functions */

U_CAPI UChar32 U_EXPORT2
ucase_tolower(const UCaseProps *csp, UChar32 c);

U_CAPI UChar32 U_EXPORT2
ucase_toupper(const UCaseProps *csp, UChar32 c);

U_CAPI UChar32 U_EXPORT2
ucase_totitle(const UCaseProps *csp, UChar32 c);

U_CAPI UChar32 U_EXPORT2
ucase_fold(const UCaseProps *csp, UChar32 c, uint32_t options);

/**
 * Adds all simple case mappings and the full case folding for c to sa,
 * and also adds special case closure mappings.
 * c itself is not added.
 * For example, the mappings
 * - for s include long s
 * - for sharp s include ss
 * - for k include the Kelvin sign
 */
U_CFUNC void U_EXPORT2
ucase_addCaseClosure(const UCaseProps *csp, UChar32 c, const USetAdder *sa);

/**
 * Maps the string to single code points and adds the associated case closure
 * mappings.
 * The string is mapped to code points if it is their full case folding string.
 * In other words, this performs a reverse full case folding and then
 * adds the case closure items of the resulting code points.
 * If the string is found and its closure applied, then
 * the string itself is added as well as part of its code points' closure.
 * It must be length>=0.
 *
 * @return TRUE if the string was found
 */
U_CFUNC UBool U_EXPORT2
ucase_addStringCaseClosure(const UCaseProps *csp, const UChar *s, int32_t length, const USetAdder *sa);

/** @return UCASE_NONE, UCASE_LOWER, UCASE_UPPER, UCASE_TITLE */
U_CAPI int32_t U_EXPORT2
ucase_getType(const UCaseProps *csp, UChar32 c);

/** @return same as ucase_getType(), or <0 if c is case-ignorable */
U_CAPI int32_t U_EXPORT2
ucase_getTypeOrIgnorable(const UCaseProps *csp, UChar32 c);

U_CAPI UBool U_EXPORT2
ucase_isSoftDotted(const UCaseProps *csp, UChar32 c);

U_CAPI UBool U_EXPORT2
ucase_isCaseSensitive(const UCaseProps *csp, UChar32 c);

/* string case mapping functions */

/**
 * Iterator function for string case mappings, which need to look at the
 * context (surrounding text) of a given character for conditional mappings.
 *
 * The iterator only needs to go backward or forward away from the
 * character in question. It does not use any indexes on this interface.
 * It does not support random access or an arbitrary change of
 * iteration direction.
 *
 * The code point being case-mapped itself is never returned by
 * this iterator.
 *
 * @param context A pointer to the iterator's working data.
 * @param dir If <0 then start iterating backward from the character;
 *            if >0 then start iterating forward from the character;
 *            if 0 then continue iterating in the current direction.
 * @return Next code point, or <0 when the iteration is done.
 */
typedef UChar32 U_CALLCONV
UCaseContextIterator(void *context, int8_t dir);

/**
 * Sample struct which may be used by some implementations of
 * UCaseContextIterator.
 */
struct UCaseContext {
    void *p;
    int32_t start, index, limit;
    int32_t cpStart, cpLimit;
    int8_t dir;
    int8_t b1, b2, b3;
};
typedef struct UCaseContext UCaseContext;

enum {
    /**
     * For string case mappings, a single character (a code point) is mapped
     * either to itself (in which case in-place mapping functions do nothing),
     * or to another single code point, or to a string.
     * Aside from the string contents, these are indicated with a single int32_t
     * value as follows:
     *
     * Mapping to self: Negative values (~self instead of -self to support U+0000)
     *
     * Mapping to another code point: Positive values >UCASE_MAX_STRING_LENGTH
     *
     * Mapping to a string: The string length (0..UCASE_MAX_STRING_LENGTH) is
     * returned. Note that the string result may indeed have zero length.
     */
    UCASE_MAX_STRING_LENGTH=0x1f
};

/**
 * Get the full lowercase mapping for c.
 *
 * @param csp Case mapping properties.
 * @param c Character to be mapped.
 * @param iter Character iterator, used for context-sensitive mappings.
 *             See UCaseContextIterator for details.
 *             If iter==NULL then a context-independent result is returned.
 * @param context Pointer to be passed into iter.
 * @param pString If the mapping result is a string, then the pointer is
 *                written to *pString.
 * @param locale Locale ID for locale-dependent mappings.
 * @param locCache Initialize to 0; may be used to cache the result of parsing
 *                 the locale ID for subsequent calls.
 *                 Can be NULL.
 * @return Output code point or string length, see UCASE_MAX_STRING_LENGTH.
 *
 * @see UCaseContextIterator
 * @see UCASE_MAX_STRING_LENGTH
 * @internal
 */
U_CAPI int32_t U_EXPORT2
ucase_toFullLower(const UCaseProps *csp, UChar32 c,
                  UCaseContextIterator *iter, void *context,
                  const UChar **pString,
                  const char *locale, int32_t *locCache);

U_CAPI int32_t U_EXPORT2
ucase_toFullUpper(const UCaseProps *csp, UChar32 c,
                  UCaseContextIterator *iter, void *context,
                  const UChar **pString,
                  const char *locale, int32_t *locCache);

U_CAPI int32_t U_EXPORT2
ucase_toFullTitle(const UCaseProps *csp, UChar32 c,
                  UCaseContextIterator *iter, void *context,
                  const UChar **pString,
                  const char *locale, int32_t *locCache);

U_CAPI int32_t U_EXPORT2
ucase_toFullFolding(const UCaseProps *csp, UChar32 c,
                    const UChar **pString,
                    uint32_t options);

U_CFUNC int32_t U_EXPORT2
ucase_hasBinaryProperty(UChar32 c, UProperty which);


U_CDECL_BEGIN

/**
 * @internal
 */
typedef int32_t U_CALLCONV
UCaseMapFull(const UCaseProps *csp, UChar32 c,
             UCaseContextIterator *iter, void *context,
             const UChar **pString,
             const char *locale, int32_t *locCache);

U_CDECL_END

/* file definitions --------------------------------------------------------- */

#define UCASE_DATA_NAME "ucase"
#define UCASE_DATA_TYPE "icu"

/* format "cAsE" */
#define UCASE_FMT_0 0x63
#define UCASE_FMT_1 0x41
#define UCASE_FMT_2 0x53
#define UCASE_FMT_3 0x45

/* indexes into indexes[] */
enum {
    UCASE_IX_INDEX_TOP,
    UCASE_IX_LENGTH,
    UCASE_IX_TRIE_SIZE,
    UCASE_IX_EXC_LENGTH,
    UCASE_IX_UNFOLD_LENGTH,

    UCASE_IX_MAX_FULL_LENGTH=15,
    UCASE_IX_TOP=16
};

/* definitions for 16-bit case properties word ------------------------------ */

/* 2-bit constants for types of cased characters */
#define UCASE_TYPE_MASK     3
enum {
    UCASE_NONE,
    UCASE_LOWER,
    UCASE_UPPER,
    UCASE_TITLE
};

#define UCASE_GET_TYPE(props) ((props)&UCASE_TYPE_MASK)

#define UCASE_SENSITIVE     4
#define UCASE_EXCEPTION     8

#define UCASE_DOT_MASK      0x30
enum {
    UCASE_NO_DOT=0,         /* normal characters with cc=0 */
    UCASE_SOFT_DOTTED=0x10, /* soft-dotted characters with cc=0 */
    UCASE_ABOVE=0x20,       /* "above" accents with cc=230 */
    UCASE_OTHER_ACCENT=0x30 /* other accent character (0<cc!=230) */
};

/* no exception: bits 15..6 are a 10-bit signed case mapping delta */
#define UCASE_DELTA_SHIFT   6
#define UCASE_DELTA_MASK    0xffc0
#define UCASE_MAX_DELTA     0x1ff
#define UCASE_MIN_DELTA     (-UCASE_MAX_DELTA-1)

#define UCASE_GET_DELTA(props) ((int16_t)(props)>>UCASE_DELTA_SHIFT)

/* case-ignorable uses one of the delta bits, see gencase/store.c */
#define UCASE_CASE_IGNORABLE 0x40

/* exception: bits 15..4 are an unsigned 12-bit index into the exceptions array */
#define UCASE_EXC_SHIFT     4
#define UCASE_EXC_MASK      0xfff0
#define UCASE_MAX_EXCEPTIONS 0x1000

/* definitions for 16-bit main exceptions word ------------------------------ */

/* first 8 bits indicate values in optional slots */
enum {
    UCASE_EXC_LOWER,
    UCASE_EXC_FOLD,
    UCASE_EXC_UPPER,
    UCASE_EXC_TITLE,
    UCASE_EXC_4,            /* reserved */
    UCASE_EXC_5,            /* reserved */
    UCASE_EXC_CLOSURE,
    UCASE_EXC_FULL_MAPPINGS,
    UCASE_EXC_ALL_SLOTS     /* one past the last slot */
};

/* each slot is 2 uint16_t instead of 1 */
#define UCASE_EXC_DOUBLE_SLOTS      0x100

/* reserved: exception bits 11..9 */

/* UCASE_EXC_DOT_MASK=UCASE_DOT_MASK<<UCASE_EXC_DOT_SHIFT */
#define UCASE_EXC_DOT_SHIFT     8

/* normally stored in the main word, but pushed out for larger exception indexes */
#define UCASE_EXC_DOT_MASK      0x3000
enum {
    UCASE_EXC_NO_DOT=0,
    UCASE_EXC_SOFT_DOTTED=0x1000,
    UCASE_EXC_ABOVE=0x2000,         /* "above" accents with cc=230 */
    UCASE_EXC_OTHER_ACCENT=0x3000   /* other character (0<cc!=230) */
};

/* complex/conditional mappings */
#define UCASE_EXC_CONDITIONAL_SPECIAL   0x4000
#define UCASE_EXC_CONDITIONAL_FOLD      0x8000

/* definitions for lengths word for full case mappings */
#define UCASE_FULL_LOWER    0xf
#define UCASE_FULL_FOLDING  0xf0
#define UCASE_FULL_UPPER    0xf00
#define UCASE_FULL_TITLE    0xf000

/* maximum lengths */
#define UCASE_FULL_MAPPINGS_MAX_LENGTH (4*0xf)
#define UCASE_CLOSURE_MAX_LENGTH 0xf

/* constants for reverse case folding ("unfold") data */
enum {
    UCASE_UNFOLD_ROWS,
    UCASE_UNFOLD_ROW_WIDTH,
    UCASE_UNFOLD_STRING_WIDTH
};

U_CDECL_END

#endif