A Basque stemming algorithm

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Tar-gzipped file of the delivered resources

Basque suffixes (as referenced below)

From: Mikel Otxandorena 
Date: Mon, 26 Jul 2010 13:04:19 +0200
Subject: Basque Snowball Stemmer

Hi,

As I told you the other day, I am sending you a valid version of a
Basque stemmer.

I have tested it with a dictionary that I attach in the
email and it works well.

For our use of suffixes see the following table:

http://www.santurtzieus.com/gelairekia/unitateak/3/lagun/atzizkien_zerrenda.htm

We are open to feedback and discussion about the linguistics,
and about the final form of the snowball implementation.

Please distribute this freely, with a mention of the author and
of the company iSOCO, that has let us share our work freely with the
Snowball community.

Kind Regards,

Mikel Otxandorena

routines (
           aditzak
           izenak
           adjetiboak
           mark_regions
           RV R2 R1
)

externals ( stem )

integers ( pV p1 p2 )

groupings ( v )

stringescapes {}

/* special characters (in ISO Latin I) */

stringdef n~ hex 'f1'

define v 'aeiou'

define mark_regions as (

    $pV = limit
    $p1 = limit
    $p2 = limit  // defaults

    do (
        ( v (non-v gopast v) or (v gopast non-v) )
        or
        ( non-v (non-v gopast v) or (v next) )
        setmark pV
    )
    do (
        gopast v gopast non-v setmark p1
        gopast v gopast non-v setmark p2
    )
)

backwardmode (

    define RV as $pV <= cursor
    define R2 as $p2 <= cursor
    define R1 as $p1 <= cursor

    define aditzak as (
        [substring] among(
            'le' 'la' 'tzaile' 'aldatu' 'atu' 'tzailea' 'taile' 'tailea' 'pera' 'gale' 'galea'
            'gura' 'kura' 'kor' 'korra' 'or' 'orra' 'tun' 'tuna' 'gaitz' 'gaitza'
            'kaitz' 'kaitza' 'ezin' 'ezina' 'tezin' 'tezina' 'errez' 'erreza'
            'karri' 'karria' 'tzaga' 'tzaka' 'tzake' 'tzeke' 'ez' 'eza' 'tzez'
            'keta' 'eta' 'etan' 'pen' 'pena' 'tze' 'atze' 'kuntza' 'kunde' 'kundea'
            'kune' 'kunea' 'kuna' 'kera' 'era' 'kizun' 'kizuna' 'dura' 'tura' 'men' 'mena'
            'go' 'ago' 'tio' 'taldi' 'taldia' 'aldi' 'aldia' 'gune' 'gunea' 'bide' 'bidea'
            'pide' 'pidea' 'gai' 'gaia' 'ki' 'kin' 'rekin' 'kina' 'kari' 'karia' 'ari' 'tari' 'etari'
            'gailu' 'gailua' 'kide' 'kidea' 'ide' 'idea' 'du' 'ka' 'kan' 'an' 'ean' 'tu' 'lari' 'tatu'
            'rean' 'tarazi' 'arazi' 'tzat' 'bera' 'dako'
            ( RV delete )
            'garri' 'garria' 'tza'
            (R2 delete)
            'atseden'
            (<- 'atseden')
            'arabera'
            (<- 'arabera')
            'baditu'
            (<- 'baditu')

        )
    )

    define izenak as (
        [substring] among(
            'ari' 'aria' 'bizia' 'kari' 'karia' 'lari' 'laria' 'tari' 'taria' 'zain' 'zaina'
            'tzain' 'tzaina' 'zale' 'zalea' 'tzale' 'tzalea' 'aizun' 'orde' 'ordea'
            'burua' 'ohi' 'ohia' 'kintza' 'gintzo' 'gintzu' 'tzu' 'tzua'
            'tzo' 'tzoa' 'kuntza' 'talde' 'taldea' 'eria' 'keria' 'teria' 'di'
            'za' 'ada' 'tara' 'etara' 'tra' 'ta' 'tegi' 'tegia' 'keta' 'z' 'zko' 'zkoa'
            'ti' 'tia' 'tsu' 'tsua' 'zu' 'zua' 'bera' 'pera' 'zto' 'ztoa' 'asi' 'asia'
            'gile' 'gilea' 'estu' 'estua' 'larri' 'larria' 'nahi' 'nahia'
            'koi' 'koia' 'oi' 'oia' 'goi' 'min' 'mina' 'dun' 'duna' 'duru' 'durua'
            'duri' 'duria' 'os' 'osa' 'oso' 'osoa' 'ar' 'ara' 'tar' 'dar' 'dara'
            'tiar' 'tiara' 'liar' 'liara' 'gabe' 'gabea' 'kabe' 'kabea' 'ga' 'ge'
            'kada' 'tasun' 'tasuna' 'asun' 'asuna' 'go' 'mendu' 'mendua' 'mentu' 'mentua'
            'mendi' 'mendia' 'zio' 'zioa' 'zino' 'zinoa' 'zione' 'zionea' 'ezia'
            'degi' 'degia' 'egi' 'egia' 'toki' 'tokia' 'leku' 'lekua' 'gintza' 'alde'
            'aldea' 'kalde' 'kaldea' 'gune' 'gunea' 'une' 'unea' 'una' 'pe' 'pea'
            'gibel' 'gibela' 'ondo' 'ondoa' 'arte' 'artea' 'aurre' 'aurrea'
            'etxe' 'etxea' 'ola' 'ontzi' 'ontzia' 'gela' 'denda' 'taldi' 'taldia'
            'aldi' 'aldia' 'te' 'tea' 'zaro' 'zaroa' 'taro' 'taroa' 'oro' 'oroa'
            'aro' 'aroa' 'ero' 'eroa' 'eroz' 'eroza' 'ka' 'kan' 'kana' 'tako' 'etako' 'takoa'
            'kote' 'kotea' 'tzar' 'tzarra' 'handi' 'handia' 'kondo' 'kondoa' 'skila'
            'no' 'noa' '{n~}o' '{n~}oa' 'ska' 'xka' 'zka' 'tila' 'to' 'toa' 'tto' 'ttoa'
            'txo' 'txoa' 'txu' 'txua' 'anda' 'anga' 'urren' 'urrena' 'gai' 'gaia'
            'gei' 'geia' 'eme' 'emea' 'kume' 'kumea' 'sa' 'ko' 'eko' 'koa' 'ena'
            'enea' 'ne' 'nea' 'kor' 'korra' 'ez' 'eza' 'eta' 'etan'
            'ki' 'kia' 'kin' 'kina' 'tu' 'tua' 'du' 'dua' 'ek'
            'tarik' 'tariko' 'tan' 'ordu' 'ordua' 'oste' 'ostea' 'tzara'
            'ra' 'antza' 'behar' 'ro' 'giro' 'ak' 'zp' 'ket'
            'kail' 'kaila' 'ail' 'kirri' 'kirria' 'ngo' 'ngoa' '{n~}i' 'sko'
            'sta' 'koitz' 'koitza' 'na' 'garren' 'garrena' 'kera'
            'gerren' 'gerrena' 'garna' 'kide' 'tz' 'tuko'
            ( RV delete )
            'ora' 'garri' 'garria' 'or' 'buru' 'ren' 'tza'
            ( R2 delete )
            'joka'
            (<- 'jok')
            'tzen' 'ten' 'en' 'tatu'
            (R1 delete)
            'trako'
            (<- 'tra')
            'minutuko'
            (<- 'minutu')
            'zehar'
            (<- 'zehar')
            'geldi'
            (<- 'geldi')
            'igaro'
            (<- 'igaro')
            'aurka'
            (<- 'aurka')
        )
    )

    define adjetiboak as (
        [substring] among(
            'era' 'ero' 'go' 'tate' 'tade' 'date' 'dade' 'keria'
            'ki' 'to' 'ro' 'la' 'gi' 'larik' 'lanik' 'ik' 'ztik' 'rik'
            ( RV delete )
            'zlea'
            (<- 'z')
        )
    )

)

define stem as (
    do mark_regions
    backwards (
        repeat aditzak
        repeat izenak
        do adjetiboak
    )

)

/*
    Note 1: additions of 21 Jul 2010
*/