step1a ( str -- newstr )
Porter stemming algorithm

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Vocabulary
porter-stemmer

Inputs

str

a string

Outputs

newstr

a new string

Word description
Gets rid of plurals.

Examples

Input	Output
caresses	caress
ponies	poni
ties	ti
caress	caress
cats	cat

Definition

USING: combinators kernel sequences splitting ;

IN: porter-stemmer

: step1a ( str -- newstr )
    dup last 115 = [
        {
            { [ "sses" ?tail ] [ "ss" append ] }
            { [ "ies" ?tail ] [ "i" append ] }
            { [ dup "ss" tail? ] [ ] }
            { [ "s" ?tail ] [ ] }
            [ ]
        } cond
    ] when ;