Scripts

## Scripts Scripts — Identifying writing systems |

## Synopsis

                        PangoScriptIter;
    enum                PangoScript;
    #define             PANGO_TYPE_SCRIPT
    PangoScript         pango_script_for_unichar            (gunichar ch);
    PangoLanguage*      pango_script_get_sample_language    (PangoScript script);
    gboolean            pango_language_includes_script      (PangoLanguage *language,
                                                             PangoScript script);
    PangoScriptIter*    pango_script_iter_new               (const char *text,
                                                             int length);
    void                pango_script_iter_get_range         (PangoScriptIter *iter,
                                                             G_CONST_RETURN char **start,
                                                             G_CONST_RETURN char **end,
                                                             PangoScript *script);
    gboolean            pango_script_iter_next              (PangoScriptIter *iter);
    void                pango_script_iter_free              (PangoScriptIter *iter);

## Description

The functions in this section are used to identify the writing system, or script of individual characters and of ranges within a larger text string.

## Details

### PangoScriptIter

    typedef struct _PangoScriptIter PangoScriptIter;

A PangoScriptIter is used to iterate through a string and identify ranges in different scripts.

### enum PangoScript

    typedef enum {                         /* ISO 15924 code */
          PANGO_SCRIPT_INVALID_CODE = -1,
          PANGO_SCRIPT_COMMON       = 0,   /* Zyyy */
          PANGO_SCRIPT_INHERITED,          /* Qaai */
          PANGO_SCRIPT_ARABIC,             /* Arab */
          PANGO_SCRIPT_ARMENIAN,           /* Armn */
          PANGO_SCRIPT_BENGALI,            /* Beng */
          PANGO_SCRIPT_BOPOMOFO,           /* Bopo */
          PANGO_SCRIPT_CHEROKEE,           /* Cher */
          PANGO_SCRIPT_COPTIC,             /* Qaac */
          PANGO_SCRIPT_CYRILLIC,           /* Cyrl (Cyrs) */
          PANGO_SCRIPT_DESERET,            /* Dsrt */
          PANGO_SCRIPT_DEVANAGARI,         /* Deva */
          PANGO_SCRIPT_ETHIOPIC,           /* Ethi */
          PANGO_SCRIPT_GEORGIAN,           /* Geor (Geon, Geoa) */
          PANGO_SCRIPT_GOTHIC,             /* Goth */
          PANGO_SCRIPT_GREEK,              /* Grek */
          PANGO_SCRIPT_GUJARATI,           /* Gujr */
          PANGO_SCRIPT_GURMUKHI,           /* Guru */
          PANGO_SCRIPT_HAN,                /* Hani */
          PANGO_SCRIPT_HANGUL,             /* Hang */
          PANGO_SCRIPT_HEBREW,             /* Hebr */
          PANGO_SCRIPT_HIRAGANA,           /* Hira */
          PANGO_SCRIPT_KANNADA,            /* Knda */
          PANGO_SCRIPT_KATAKANA,           /* Kana */
          PANGO_SCRIPT_KHMER,              /* Khmr */
          PANGO_SCRIPT_LAO,                /* Laoo */
          PANGO_SCRIPT_LATIN,              /* Latn (Latf, Latg) */
          PANGO_SCRIPT_MALAYALAM,          /* Mlym */
          PANGO_SCRIPT_MONGOLIAN,          /* Mong */
          PANGO_SCRIPT_MYANMAR,            /* Mymr */
          PANGO_SCRIPT_OGHAM,              /* Ogam */
          PANGO_SCRIPT_OLD_ITALIC,         /* Ital */
          PANGO_SCRIPT_ORIYA,              /* Orya */
          PANGO_SCRIPT_RUNIC,              /* Runr */
          PANGO_SCRIPT_SINHALA,            /* Sinh */
          PANGO_SCRIPT_SYRIAC,             /* Syrc (Syrj, Syrn, Syre) */
          PANGO_SCRIPT_TAMIL,              /* Taml */
          PANGO_SCRIPT_TELUGU,             /* Telu */
          PANGO_SCRIPT_THAANA,             /* Thaa */
          PANGO_SCRIPT_THAI,               /* Thai */
          PANGO_SCRIPT_TIBETAN,            /* Tibt */
          PANGO_SCRIPT_CANADIAN_ABORIGINAL, /* Cans */
          PANGO_SCRIPT_YI,                 /* Yiii */
          PANGO_SCRIPT_TAGALOG,            /* Tglg */
          PANGO_SCRIPT_HANUNOO,            /* Hano */
          PANGO_SCRIPT_BUHID,              /* Buhd */
          PANGO_SCRIPT_TAGBANWA,           /* Tagb */

          /* Unicode-4.0 additions */
          PANGO_SCRIPT_BRAILLE,            /* Brai */
          PANGO_SCRIPT_CYPRIOT,            /* Cprt */
          PANGO_SCRIPT_LIMBU,              /* Limb */
          PANGO_SCRIPT_OSMANYA,            /* Osma */
          PANGO_SCRIPT_SHAVIAN,            /* Shaw */
          PANGO_SCRIPT_LINEAR_B,           /* Linb */
          PANGO_SCRIPT_TAI_LE,             /* Tale */
          PANGO_SCRIPT_UGARITIC,           /* Ugar */

          /* Unicode-4.1 additions */
          PANGO_SCRIPT_NEW_TAI_LUE,        /* Talu */
          PANGO_SCRIPT_BUGINESE,           /* Bugi */
          PANGO_SCRIPT_GLAGOLITIC,         /* Glag */
          PANGO_SCRIPT_TIFINAGH,           /* Tfng */
          PANGO_SCRIPT_SYLOTI_NAGRI,       /* Sylo */
          PANGO_SCRIPT_OLD_PERSIAN,        /* Xpeo */
          PANGO_SCRIPT_KHAROSHTHI,         /* Khar */

          /* Unicode-5.0 additions */
          PANGO_SCRIPT_UNKNOWN,            /* Zzzz */
          PANGO_SCRIPT_BALINESE,           /* Bali */
          PANGO_SCRIPT_CUNEIFORM,          /* Xsux */
          PANGO_SCRIPT_PHOENICIAN,         /* Phnx */
          PANGO_SCRIPT_PHAGS_PA,           /* Phag */
          PANGO_SCRIPT_NKO                 /* Nkoo */
    } PangoScript;

The PangoScript enumeration identifies different writing systems. The values correspond to the names as defined in the Unicode standard. Note that new types may be added in the future. Applications should be ready to handle unknown values. This enumeration is interchangeable with GUnicodeScript. See Unicode Standard Annex "" Script names.

`PANGO_SCRIPT_INVALID_CODE` | a value never returned from `pango_script_for_unichar()`
`PANGO_SCRIPT_COMMON` | a character used by multiple different scripts
`PANGO_SCRIPT_INHERITED` | a mark glyph that takes its script from the base glyph to which it is attached
`PANGO_SCRIPT_ARABIC` | Arabic
`PANGO_SCRIPT_ARMENIAN` | Armenian
`PANGO_SCRIPT_BENGALI` | Bengali
`PANGO_SCRIPT_BOPOMOFO` | Bopomofo
`PANGO_SCRIPT_CHEROKEE` | Cherokee
`PANGO_SCRIPT_COPTIC` | Coptic
`PANGO_SCRIPT_CYRILLIC` | Cyrillic
`PANGO_SCRIPT_DESERET` | Deseret
`PANGO_SCRIPT_DEVANAGARI` | Devanagari
`PANGO_SCRIPT_ETHIOPIC` | Ethiopic
`PANGO_SCRIPT_GEORGIAN` | Georgian
`PANGO_SCRIPT_GOTHIC` | Gothic
`PANGO_SCRIPT_GREEK` | Greek
`PANGO_SCRIPT_GUJARATI` | Gujarati
`PANGO_SCRIPT_GURMUKHI` | Gurmukhi
`PANGO_SCRIPT_HAN` | Han
`PANGO_SCRIPT_HANGUL` | Hangul
`PANGO_SCRIPT_HEBREW` | Hebrew
`PANGO_SCRIPT_HIRAGANA` | Hiragana
`PANGO_SCRIPT_KANNADA` | Kannada
`PANGO_SCRIPT_KATAKANA` | Katakana
`PANGO_SCRIPT_KHMER` | Khmer
`PANGO_SCRIPT_LAO` | Lao
`PANGO_SCRIPT_LATIN` | Latin
`PANGO_SCRIPT_MALAYALAM` | Malayalam
`PANGO_SCRIPT_MONGOLIAN` | Mongolian
`PANGO_SCRIPT_MYANMAR` | Myanmar
`PANGO_SCRIPT_OGHAM` | Ogham
`PANGO_SCRIPT_OLD_ITALIC` | Old Italic
`PANGO_SCRIPT_ORIYA` | Oriya
`PANGO_SCRIPT_RUNIC` | Runic
`PANGO_SCRIPT_SINHALA` | Sinhala
`PANGO_SCRIPT_SYRIAC` | Syriac
`PANGO_SCRIPT_TAMIL` | Tamil
`PANGO_SCRIPT_TELUGU` | Telugu
`PANGO_SCRIPT_THAANA` | Thaana
`PANGO_SCRIPT_THAI` | Thai
`PANGO_SCRIPT_TIBETAN` | Tibetan
`PANGO_SCRIPT_CANADIAN_ABORIGINAL` | Canadian Aboriginal
`PANGO_SCRIPT_YI` | Yi
`PANGO_SCRIPT_TAGALOG` | Tagalog
`PANGO_SCRIPT_HANUNOO` | Hanunoo
`PANGO_SCRIPT_BUHID` | Buhid
`PANGO_SCRIPT_TAGBANWA` | Tagbanwa
`PANGO_SCRIPT_BRAILLE` | Braille
`PANGO_SCRIPT_CYPRIOT` | Cypriot
`PANGO_SCRIPT_LIMBU` | Limbu
`PANGO_SCRIPT_OSMANYA` | Osmanya
`PANGO_SCRIPT_SHAVIAN` | Shavian
`PANGO_SCRIPT_LINEAR_B` | Linear B
`PANGO_SCRIPT_TAI_LE` | Tai Le
`PANGO_SCRIPT_UGARITIC` | Ugaritic
`PANGO_SCRIPT_NEW_TAI_LUE` | New Tai Lue
`PANGO_SCRIPT_BUGINESE` | Buginese
`PANGO_SCRIPT_GLAGOLITIC` | Glagolitic
`PANGO_SCRIPT_TIFINAGH` | Tifinagh
`PANGO_SCRIPT_SYLOTI_NAGRI` | Syloti Nagri
`PANGO_SCRIPT_OLD_PERSIAN` | Old Persian
`PANGO_SCRIPT_KHAROSHTHI` | Kharoshthi
`PANGO_SCRIPT_UNKNOWN` | an unassigned code point
`PANGO_SCRIPT_BALINESE` | Balinese
`PANGO_SCRIPT_CUNEIFORM` | Cuneiform
`PANGO_SCRIPT_PHOENICIAN` | Phoenician
`PANGO_SCRIPT_PHAGS_PA` | Phags-pa
`PANGO_SCRIPT_NKO` | N'Ko

### PANGO_TYPE_SCRIPT

    #define PANGO_TYPE_SCRIPT (pango_script_get_type())

The GObject type for PangoScript

### pango_script_for_unichar ()

    PangoScript         pango_script_for_unichar            (gunichar ch);

Looks up the PangoScript for a particular character (as defined by Unicode Standard Annex 24). No check is made for `ch` being a valid Unicode character; if you pass in invalid character, the result is undefined.

As of Pango 1.18, this function simply returns the return value of `g_unichar_get_script()`.

`ch` : | a Unicode character
Returns : | the PangoScript for the character.

Since 1.4

### pango_script_get_sample_language ()

    PangoLanguage*      pango_script_get_sample_language    (PangoScript script);

Given a script, finds a language tag that is reasonably representative of that script. This will usually be the most widely spoken or used language written in that script: for instance, the sample language for `PANGO_SCRIPT_CYRILLIC` is `ru` (Russian), the sample language for `PANGO_SCRIPT_ARABIC` is `ar`.

For some scripts, no sample language will be returned because there is no language that is sufficiently representative. The best example of this is `PANGO_SCRIPT_HAN`, where various different variants of written Chinese, Japanese, and Korean all use significantly different sets of Han characters and forms of shared characters. No sample language can be provided for many historical scripts as well.

As of 1.18, this function checks the environment variables PANGO_LANGUAGE and LANGUAGE (checked in that order) first. If one of them is set, it is parsed as a list of language tags separated by colons or other separators. This function will return the first language in the parsed list that Pango believes may use `script` for writing. This last predicate is tested using `pango_language_includes_script()`. This can be used to control Pango's font selection for non-primary languages. For example, a PANGO_LANGUAGE enviroment variable set to "en:fa" makes Pango choose fonts suitable for Persian (fa) instead of Arabic (ar) when a segment of Arabic text is found in an otherwise non-Arabic text. The same trick can be used to choose a default language for `PANGO_SCRIPT_HAN` when setting context language is not feasible.

`script` : | a PangoScript
Returns : | a PangoLanguage that is representative of the script, or `NULL` if no such language exists.

Since 1.4

### pango_language_includes_script ()

    gboolean            pango_language_includes_script      (PangoLanguage *language,
                                                             PangoScript script);

Determines if `script` is one of the scripts used to write `language`. The returned value is conservative; if nothing is known about the language tag `language`, `TRUE` will be returned, since, as far as Pango knows, `script` might be used to write `language`.

This routine is used in Pango's itemization process when determining if a supplied language tag is relevant to a particular section of text. It probably is not useful for applications in most circumstances.

`language` : | a PangoLanguage, or `NULL`
`script` : | a PangoScript
Returns : | `TRUE` if `script` is one of the scripts used to write `language` or if nothing is known about `language` (including the case that `language` is `NULL`), `FALSE` otherwise.

Since 1.4

### pango_script_iter_new ()

    PangoScriptIter*    pango_script_iter_new               (const char *text,
                                                             int length);

Create a new PangoScriptIter, used to break a string of Unicode into runs by text. No copy is made of `text`, so the caller needs to make sure it remains valid until the iterator is freed with `pango_script_iter_free()`.x

`text` : | a UTF-8 string
`length` : | length of `text`, or -1 if `text` is nul-terminated.
Returns : | the new script iterator, initialized to point at the first range in the text, which should be freed with `pango_script_iter_free()`. If the string is empty, it will point at an empty range.

Since 1.4

### pango_script_iter_get_range ()

    void                pango_script_iter_get_range         (PangoScriptIter *iter,
                                                             G_CONST_RETURN char **start,
                                                             G_CONST_RETURN char **end,
                                                             PangoScript *script);

Gets information about the range to which `iter` currently points. The range is the set of locations p where *start <= p < *end. (That is, it doesn't include the character stored at *end)

`iter` : | a PangoScriptIter
`start` : | location to store start position of the range, or `NULL`
`end` : | location to store end position of the range, or `NULL`
`script` : | location to store script for range, or `NULL`

Since 1.4

### pango_script_iter_next ()

    gboolean            pango_script_iter_next              (PangoScriptIter *iter);

Advances a PangoScriptIter to the next range. If `iter` is already at the end, it is left unchanged and `FALSE` is returned.

`iter` : | a PangoScriptIter
Returns : | `TRUE` if `iter` was successfully advanced.

Since 1.4

### pango_script_iter_free ()

    void                pango_script_iter_free              (PangoScriptIter *iter);

Frees a PangoScriptIter created with `pango_script_iter_new()`.

`iter` : | a PangoScriptIter

Since 1.4