ushape.h File Reference

C API: Arabic shaping. More...

#include "unicode/utypes.h"

Go to the source code of this file.

Defines

#define U_SHAPE_LENGTH_GROW_SHRINK   0
 Memory option: allow the result to have a different length than the source.
#define U_SHAPE_LENGTH_FIXED_SPACES_NEAR   1
 Memory option: the result must have the same length as the source.
#define U_SHAPE_LENGTH_FIXED_SPACES_AT_END   2
 Memory option: the result must have the same length as the source.
#define U_SHAPE_LENGTH_FIXED_SPACES_AT_BEGINNING   3
 Memory option: the result must have the same length as the source.
#define U_SHAPE_LENGTH_MASK   3
 Bit mask for memory options.
#define U_SHAPE_TEXT_DIRECTION_LOGICAL   0
 Direction indicator: the source is in logical (keyboard) order.
#define U_SHAPE_TEXT_DIRECTION_VISUAL_LTR   4
 Direction indicator: the source is in visual LTR order, the leftmost displayed character stored first.
#define U_SHAPE_TEXT_DIRECTION_MASK   4
 Bit mask for direction indicators.
#define U_SHAPE_LETTERS_NOOP   0
 Letter shaping option: do not perform letter shaping.
#define U_SHAPE_LETTERS_SHAPE   8
 Letter shaping option: replace abstract letter characters by "shaped" ones.
#define U_SHAPE_LETTERS_UNSHAPE   0x10
 Letter shaping option: replace "shaped" letter characters by abstract ones.
#define U_SHAPE_LETTERS_SHAPE_TASHKEEL_ISOLATED   0x18
 Letter shaping option: replace abstract letter characters by "shaped" ones.
#define U_SHAPE_LETTERS_MASK   0x18
 Bit mask for letter shaping options.
#define U_SHAPE_DIGITS_NOOP   0
 Digit shaping option: do not perform digit shaping.
#define U_SHAPE_DIGITS_EN2AN   0x20
 Digit shaping option: Replace European digits (U+0030.
#define U_SHAPE_DIGITS_AN2EN   0x40
 Digit shaping option: Replace Arabic-Indic digits by European digits (U+0030.
#define U_SHAPE_DIGITS_ALEN2AN_INIT_LR   0x60
 Digit shaping option: Replace European digits (U+0030.
#define U_SHAPE_DIGITS_ALEN2AN_INIT_AL   0x80
 Digit shaping option: Replace European digits (U+0030.
#define U_SHAPE_DIGITS_RESERVED   0xa0
 Not a valid option value.
#define U_SHAPE_DIGITS_MASK   0xe0
 Bit mask for digit shaping options.
#define U_SHAPE_DIGIT_TYPE_AN   0
 Digit type option: Use Arabic-Indic digits (U+0660.
#define U_SHAPE_DIGIT_TYPE_AN_EXTENDED   0x100
 Digit type option: Use Eastern (Extended) Arabic-Indic digits (U+06f0.
#define U_SHAPE_DIGIT_TYPE_RESERVED   0x200
 Not a valid option value.
#define U_SHAPE_DIGIT_TYPE_MASK   0x3f00
 Bit mask for digit type options.

Functions

int32_t u_shapeArabic (const UChar *source, int32_t sourceLength, UChar *dest, int32_t destSize, uint32_t options, UErrorCode *pErrorCode)
 Shape Arabic text on a character basis.


Detailed Description

C API: Arabic shaping.

Definition in file ushape.h.


Define Documentation

#define U_SHAPE_DIGIT_TYPE_AN   0

Digit type option: Use Arabic-Indic digits (U+0660.

..U+0669).

Stable:
ICU 2.0

Definition at line 223 of file ushape.h.

#define U_SHAPE_DIGIT_TYPE_AN_EXTENDED   0x100

Digit type option: Use Eastern (Extended) Arabic-Indic digits (U+06f0.

..U+06f9).

Stable:
ICU 2.0

Definition at line 226 of file ushape.h.

#define U_SHAPE_DIGIT_TYPE_MASK   0x3f00

Bit mask for digit type options.

Stable:
ICU 2.0

Definition at line 232 of file ushape.h.

#define U_SHAPE_DIGIT_TYPE_RESERVED   0x200

Not a valid option value.

May be replaced by a new option.

Stable:
ICU 2.0

Definition at line 229 of file ushape.h.

#define U_SHAPE_DIGITS_ALEN2AN_INIT_AL   0x80

Digit shaping option: Replace European digits (U+0030.

..) by Arabic-Indic digits if the most recent strongly directional character is an Arabic letter (u_charDirection() result U_RIGHT_TO_LEFT_ARABIC [AL]).
The direction of "preceding" depends on the direction indicator option. For the first characters, the preceding strongly directional character (initial state) is assumed to be an Arabic letter.

Stable:
ICU 2.0

Definition at line 213 of file ushape.h.

#define U_SHAPE_DIGITS_ALEN2AN_INIT_LR   0x60

Digit shaping option: Replace European digits (U+0030.

..) by Arabic-Indic digits if the most recent strongly directional character is an Arabic letter (u_charDirection() result U_RIGHT_TO_LEFT_ARABIC [AL]).
The direction of "preceding" depends on the direction indicator option. For the first characters, the preceding strongly directional character (initial state) is assumed to be not an Arabic letter (it is U_LEFT_TO_RIGHT [L] or U_RIGHT_TO_LEFT [R]).

Stable:
ICU 2.0

Definition at line 201 of file ushape.h.

#define U_SHAPE_DIGITS_AN2EN   0x40

Digit shaping option: Replace Arabic-Indic digits by European digits (U+0030.

..).

Stable:
ICU 2.0

Definition at line 188 of file ushape.h.

#define U_SHAPE_DIGITS_EN2AN   0x20

Digit shaping option: Replace European digits (U+0030.

..) by Arabic-Indic digits.

Stable:
ICU 2.0

Definition at line 181 of file ushape.h.

#define U_SHAPE_DIGITS_MASK   0xe0

Bit mask for digit shaping options.

Stable:
ICU 2.0

Definition at line 219 of file ushape.h.

#define U_SHAPE_DIGITS_NOOP   0

Digit shaping option: do not perform digit shaping.

Stable:
ICU 2.0

Definition at line 174 of file ushape.h.

#define U_SHAPE_DIGITS_RESERVED   0xa0

Not a valid option value.

May be replaced by a new option.

Stable:
ICU 2.0

Definition at line 216 of file ushape.h.

#define U_SHAPE_LENGTH_FIXED_SPACES_AT_BEGINNING   3

Memory option: the result must have the same length as the source.

If more room is necessary, then try to consume spaces at the beginning of the text.

Stable:
ICU 2.0

Definition at line 130 of file ushape.h.

#define U_SHAPE_LENGTH_FIXED_SPACES_AT_END   2

Memory option: the result must have the same length as the source.

If more room is necessary, then try to consume spaces at the end of the text.

Stable:
ICU 2.0

Definition at line 123 of file ushape.h.

#define U_SHAPE_LENGTH_FIXED_SPACES_NEAR   1

Memory option: the result must have the same length as the source.

If more room is necessary, then try to consume spaces next to modified characters.

Stable:
ICU 2.0

Definition at line 116 of file ushape.h.

#define U_SHAPE_LENGTH_GROW_SHRINK   0

Memory option: allow the result to have a different length than the source.

Stable:
ICU 2.0

Definition at line 109 of file ushape.h.

#define U_SHAPE_LENGTH_MASK   3

Bit mask for memory options.

Stable:
ICU 2.0

Definition at line 133 of file ushape.h.

#define U_SHAPE_LETTERS_MASK   0x18

Bit mask for letter shaping options.

Stable:
ICU 2.0

Definition at line 170 of file ushape.h.

#define U_SHAPE_LETTERS_NOOP   0

Letter shaping option: do not perform letter shaping.

Stable:
ICU 2.0

Definition at line 152 of file ushape.h.

#define U_SHAPE_LETTERS_SHAPE   8

Letter shaping option: replace abstract letter characters by "shaped" ones.

Stable:
ICU 2.0

Definition at line 155 of file ushape.h.

#define U_SHAPE_LETTERS_SHAPE_TASHKEEL_ISOLATED   0x18

Letter shaping option: replace abstract letter characters by "shaped" ones.

The only difference with U_SHAPE_LETTERS_SHAPE is that Tashkeel letters are always "shaped" into the isolated form instead of the medial form (selecting code points from the Arabic Presentation Forms-B block).

Stable:
ICU 2.0

Definition at line 167 of file ushape.h.

#define U_SHAPE_LETTERS_UNSHAPE   0x10

Letter shaping option: replace "shaped" letter characters by abstract ones.

Stable:
ICU 2.0

Definition at line 158 of file ushape.h.

#define U_SHAPE_TEXT_DIRECTION_LOGICAL   0

Direction indicator: the source is in logical (keyboard) order.

Stable:
ICU 2.0

Definition at line 137 of file ushape.h.

#define U_SHAPE_TEXT_DIRECTION_MASK   4

Bit mask for direction indicators.

Stable:
ICU 2.0

Definition at line 148 of file ushape.h.

#define U_SHAPE_TEXT_DIRECTION_VISUAL_LTR   4

Direction indicator: the source is in visual LTR order, the leftmost displayed character stored first.

Stable:
ICU 2.0

Definition at line 145 of file ushape.h.


Function Documentation

int32_t u_shapeArabic ( const UChar *  source,
int32_t  sourceLength,
UChar *  dest,
int32_t  destSize,
uint32_t  options,
UErrorCode pErrorCode 
)

Shape Arabic text on a character basis.

This function performs basic operations for "shaping" Arabic text. It is most useful for use with legacy data formats and legacy display technology (simple terminals). All operations are performed on Unicode characters.

Text-based shaping means that some character code points in the text are replaced by others depending on the context. It transforms one kind of text into another. In comparison, modern displays for Arabic text select appropriate, context-dependent font glyphs for each text element, which means that they transform text into a glyph vector.

Text transformations are necessary when modern display technology is not available or when text needs to be transformed to or from legacy formats that use "shaped" characters. Since the Arabic script is cursive, connecting adjacent letters to each other, computers select images for each letter based on the surrounding letters. This usually results in four images per Arabic letter: initial, middle, final, and isolated forms. In Unicode, on the other hand, letters are normally stored abstract, and a display system is expected to select the necessary glyphs. (This makes searching and other text processing easier because the same letter has only one code.) It is possible to mimic this with text transformations because there are characters in Unicode that are rendered as letters with a specific shape (or cursive connectivity). They were included for interoperability with legacy systems and codepages, and for unsophisticated display systems.

A second kind of text transformations is supported for Arabic digits: For compatibility with legacy codepages that only include European digits, it is possible to replace one set of digits by another, changing the character code points. These operations can be performed for either Arabic-Indic Digits (U+0660...U+0669) or Eastern (Extended) Arabic-Indic digits (U+06f0...U+06f9).

Some replacements may result in more or fewer characters (code points). By default, this means that the destination buffer may receive text with a length different from the source length. Some legacy systems rely on the length of the text to be constant. They expect extra spaces to be added or consumed either next to the affected character or at the end of the text.

For details about the available operations, see the description of the U_SHAPE_... options.

Parameters:
source The input text.
sourceLength The number of UChars in source.
dest The destination buffer that will receive the results of the requested operations. It may be NULL only if destSize is 0. The source and destination must not overlap.
destSize The size (capacity) of the destination buffer in UChars. If destSize is 0, then no output is produced, but the necessary buffer size is returned ("preflighting").
options This is a 32-bit set of flags that specify the operations that are performed on the input text. If no error occurs, then the result will always be written to the destination buffer.
pErrorCode must be a valid pointer to an error code value, which must not indicate a failure before the function call.
Returns:
The number of UChars written to the destination buffer. If an error occured, then no output was written, or it may be incomplete. If U_BUFFER_OVERFLOW_ERROR is set, then the return value indicates the necessary destination buffer size.
Stable:
ICU 2.0


Generated on Mon Aug 13 07:17:28 2007 for ICU 3.6 by  doxygen 1.5.2