/ 
ShiftJIS-Collate-1.10
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/ ShiftJIS::Collate

NAME

ShiftJIS::Collate - collation of Shift-JIS strings

SYNOPSIS

use ShiftJIS::Collate;

@sorted = ShiftJIS::Collate->new(%tailoring)->sort(@source);

DESCRIPTION

This module provides some functions to compare and sort strings in Shift-JIS based on JIS X 4061:1996, collation of Japanese character strings, "Nihongo mojiretsu shogo junban".

This module is an implementation of JIS X 4061:1996 and the collation rules are based on that standard. See Conformance to the Standard.

Constructor and Tailoring

The new method returns a collator object.

$Collator = ShiftJIS::Collate->new(
   ignoreChar => $regexIgnoredChar,
   kanji => $kanji_class,
   katakana_before_hiragana => $bool,
   level => $collationLevel,
   position_in_bytes => $bool,
   tounicode  => \&sjis_to_unicode,
   preprocess => \&preprocess,
   upper_before_lower => $bool,
);
# if %tailoring is false (empty),
# $Collator should do the default collation.
ignoreChar

If specified as a regular expression, any characters that match it are ignored on collation.

e.g. If you want to ignore KATAKANA-HIRAGANA PROLONGED SOUND MARK and its halfwidth form, say

ignoreChar => '^(?:\x81\x5B|\xB0)',
katakana_before_hiragana

By default, hiragana is before katakana.

If the parameter is true, this is reversed.

kanji

Set the kanji class. See "Kanji Classes".

Class 1: 'saisho' (minimal)
Class 2: 'kihon' (basic)
Class 3: 'kakucho' (extended)

The kanji class is specified as 1, 2, or 3. If omitted, class 2 is applied.

This module does not support 'kakucho' kanji class, since the repertoire of Shift-JIS does not define all the Unicode CJK unified ideographs.

But if the kanji class 3 is specified, you can collate kanji in the unicode order. In this case you must provide tounicode coderef which gives a unicode codepoint from a Shift-JIS character.

level

Set the maximum level. See "Collation Levels". Any higher levels than the specified one are ignored.

Level 1: alphabetic ordering
Level 2: diacritic ordering
Level 3: case ordering
Level 4: script ordering
Level 5: width ordering

The collation level is specified as a number between 1 and 5. If omitted, level 4 is applied.

tounicode

If you want to collate kanji in the unicode order, specify a coderef which gives a unicode codepoint from a Shift-JIS character.

Such a subroutine should map a string comprising of a kanji of level 1 and 2 in Shift-JIS to a codepoint in the range between 0x4E00 and 0x9FFF.

position_in_bytes

By default, the index method returns its results in characters.

If this parameter is true, it returns the results in bytes.

preprocess

If specified, the coderef is used to preprocess before the formation of sort keys. I.e. a sort key is formed from a return value returned by the coderef.

upper_before_lower

By default, lowercase is before uppercase.

If the parameter is true, this is reversed.

Comparison

$result = $Collator->cmp($a, $b)

Returns 1 (when $a is greater than $b) or 0 (when $a is equal to $b) or -1 (when $a is lesser than $b).

$result = $Collator->eq($a, $b)
$result = $Collator->ne($a, $b)
$result = $Collator->gt($a, $b)
$result = $Collator->ge($a, $b)
$result = $Collator->lt($a, $b)
$result = $Collator->le($a, $b)

They works like the same name operators as theirs.

Sorting

$sortKey = $Collator->getSortKey($string)

Returns a sort key.

You compare the sort keys using a binary comparison and get the result of the comparison of the strings.

$Collator->getSortKey($a) cmp $Collator->getSortKey($b)

   is equivalent to

$Collator->cmp($a, $b)
@sorted = $Collator->sort(@source)

Sorts a list of strings by tanjun shogo: 'the simple collation'.

@sorted = $Collator->sortYomi(@source)

Sorts a list of references to arrays of (spell, reading) by yomi-hyoki shogo: 'the collation using readings and spells'.

Yomi-hyoki shogo is carried out through two comparison stages.

First, order by reading; next, order by spelling among strings having the same reading.

See also sample/yomi.txt.

@sorted = $Collator->sortDaihyo(@source)

Sorts a list of references to arrays of (spell, reading) by kan'i-daihyo-yomi shogo: 'the simplified representative reading collation'.

Note: This module does not support kihon-daihyo-yomi shogo: 'the basic representative reading collation', in which daihyo-yomi jisho, a dictionary of representative readings, is required.

kan'i-daihyo-yomi shogo is carried out through five comparison stages. This ordered list is an example of the result of "kan'i-daihyo-yomi shogo".

(1) Compare the character class of the first character of the spell.

(2) Compare the first character of the reading.

(3) Compare the first character of the spell.

(4) Compare the whole string of the reading.

(5) Compare the whole string of the spell.

See also sample/daihyo.txt.

Searching

$position = $Collator->index($string, $substring)
($position, $length) = $Collator->index($string, $substring)

If $substring matches a part of $string, returns the position of the first occurrence of the matching part in scalar context; in list context, returns a two-element list of the position and the length of the matching part.

Notice that the length of the matching part may differ from the length of $substring.

If $substring does not match any part of $string, returns -1 in scalar context and an empty list in list context.

If your substr function is aware of Shift-JIS, specify true as position_in_bytes. See "Constructor and Tailoring".

NOTE

Collation Levels

The following criteria are considered in order until the collation order is determined. By default, Levels 1 to 4 are applied and Level 5 is ignored, for JIS X 4061 does not specify level 5.

Level 1: alphabetic ordering.

Character classes ordered as following:

 1    space
 2   'kijutsu kigou' (punctuation marks)
 3   'kakko kigou' (quotes, parentheses, and braces)
 4   'gakujutsu kigou' (mathematical and technical signs)
 5   'ippan kigou' (general symbols)
 6   'tan-i kigou' (unit signs)
 7    digits (European)
 8   'ouji kigou' (Greek and Cyrillic letters, as "European signs")
 9    Latin alphabets
10    kana (hiragana and katakana)
11    kanji
12   'geta' mark

In the class, alphabets are collated alphabetically; kana letters are AIUEO-betically (in the Gozyuon order); kanji are in the JIS X 0208 order.

According to JIS X 4061, GETA MARK (0x81AC, U+3013) must be the greatest character (ordered at the last).

Any character for which the order is no defined, like control characters, box drawings, unassigned characters, etc. is regarded as a completely ignorable character.

Level 2: diacritic ordering.

In kana, the order is as shown the following list.

A voiceless kana, the voiced, then the semi-voiced (if exists).
Level 3: case ordering.

A small Latin is lesser than the corresponding Capital.

In kana, the order is as shown the following list. see Replacement of PROLONGED SOUND MARK and ITERATION MARKs.

Replaced PROLONGED SOUND MARKs (U+30FC and U+FF70);
Small Kana;
Replaced ITERATION MARKs (U+309D, U+309E, U+30FD, and U+30FE);
then, Normal Kana.
Level 4: script ordering.

Any hiragana is lesser than the corresponding katakana.

Level 5: width ordering.

A character that belongs to the block Halfwidth and Fullwidth Forms is greater than the corresponding normal character.

BN: JIS X 4061 does not mention this level. Level 5 is an extention by this module.

Kanji Classes

JIS X 4061 specifies three Kanji Classes. This modules supports 'Saisho' and 'Kihon' Kanji Classes.

the 'saisho' (minimal) kanji class

It comprises five kanji-like characters:

0x8156 (U+3003)
0x8157 (U+4EDD)
0x8158 (U+3005)
0x8159 (U+3006)
0x815A (U+3007)

Any kanji except U+4EDD are ignored on collation.

the 'kihon' (basic) kanji class

It comprises JIS level 1 and 2 kanji in addition to the minimal kanji class. Sorted in the JIS codepoint order. Any kanji excepting those defined by JIS X 0208 are ignored on collation.

the 'kakucho' (extended) kanji class

All the CJK Unified Ideographs in addition to the minimal kanji class. Sorted in the Unicode codepoint order.

Replacement of PROLONGED SOUND MARKs and ITERATION MARKs

SJIS    UCS     Name

0x815B  U+30FC  KATAKANA-HIRAGANA PROLONGED SOUND MARK
0xB0    U+FF70  HALFWIDTH KATAKANA-HIRAGANA PROLONGED SOUND MARK
0x8154  U+309D  HIRAGANA ITERATION MARK
0x8155  U+309E  HIRAGANA VOICED ITERATION MARK
0x8152  U+30FD  KATAKANA ITERATION MARK
0x8153  U+30FE  KATAKANA VOICED ITERATION MARK

These characters, if replaced, are secondary equal to the replacing kana, while ternary not equal to.

KATAKANA-HIRAGANA PROLONGED SOUND MARKs

The PROLONGED MARKs (including the halfwidth equivalent) are repleced to a normal vowel or nasal katakana corresponding to the preceding kana if exists.

HIRAGANA- and KATAKANA ITERATION MARKs

The ITERATION MARKs (VOICELESS) are repleced to a normal kana corresponding to the preceding kana if exists.

HIRAGANA- and KATAKANA VOICED ITERATION MARKs

The VOICED ITERATION MARKs are repleced to a voiced kana corresponding to the preceding kana if exists.

Cases of no replacement

Otherwise, no replacement occurs. Especially in the cases when these marks follow any character except kana.

The unreplaced characters are primary greater than any kana.

e.g.  CJK Ideograph followed by PROLONGED SOUND MARK
      Digit followed by ITERATION MARK
      Kana that has no voiced variant followed by VOICED ITERATION MARK

Conformance to the Standard [JIS X 4061, 6.2]

(1) charset: Shift-JIS.

(2) No limit of the number of characters in the string considered
    to collate.

(3) No character class is added.

(4) The following characters are added as collation elements.

    IDEOGRAPHIC SPACE is added in the space class.

    ACUTE ACCENT, GRAVE ACCENT, DIAERESIS, CIRCUMFLEX ACCENT
    are added in 'kijutsu kigou'.

    APOSTROPHE, QUOTATION MARK are added in 'kakko kigou'.

    HYPHEN-MINUS is added in 'gakujutsu kigou'.

(5) Collation of Latin alphabets with macron and with circumflex
    is not supported.

(6) Kanji Classes:
     i) the minimal kanji class (Five kanji-like chars).
     ii) the basic kanji class (Levels 1 and 2 kanji of JIS)..

AUTHOR

SADAHIRO Tomoyuki <SADAHIRO@cpan.org>

Copyright(C) 2001-2007, SADAHIRO Tomoyuki. Japan. All rights reserved.

This module is free software; you can redistribute it
and/or modify it under the same terms as Perl itself.

SEE ALSO

JIS X 4061

Collation of Japanese character strings

JIS X 0201

7-bit and 8-bit coded character sets for information interchange

JIS X 0208

7-bit and 8-bit double byte coded KANJI sets for information interchange

JIS X 0221

Information technology - Universal Multiple-Octet Coded Character Set (UCS) - part 1 : Architectute and Basic Multilingual Plane

Japanese Industrial Standards Committee (JISC)

http://www.jisc.go.jp/

Japanese Standards Association (JSA)

http://www.jsa.or.jp/

ShiftJIS::String
ShiftJIS::Regexp