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Perstem: Persian stemmer, morphological analyzer, transliterator

Persian (Farsi) stemmer, morphological analyzer, transliterator, and partial part-of-speech tagger. Input may be encoded as Perso-Arabic script UTF-8, ISIRI 3342, Windows-1256, SGML/HTML/XML-style numeric character references (ncr), or dehdari-transliterated latin-script text. Use the -i flag to specify input encoding. Output is handled similarly.


  perl [options] < input > output


 -f, --form <x>         Output forms as one of the following:
                          dict: as they appear in a dictionary (default)
                          linked: show all morphemes, linked together
                          unlinked: show all morphemes as separate tokens
                          untouched: don't stem/analyze; mostly for char-set conversion
     --flush            Autoflush buffer output after every line
 -h, --help             Print this usage
 -i, --input <type>     Input character encoding type {cp1256,isiri3342,ncr,
                        translit,utf8} (default: utf8)
     --irreg-stem {0|1} Resolve irregular present-tense verb stems to their
                        past-tense stems (eg. kon -> kar).  (default: 1 == true)
 -n, --noroman          Delete all non-Arabic script characters (eg. HTML tags)
 -o, --output <type>    Output character encoding type {arabtex,cp1256,
                        isiri3342,ncr,translit,utf8} (default: utf8)
 -p, --pos              Tag inflected words for parts of speech
     --pos-sep <char>   Separate words from their parts of speech by <char>
                        (default: "/" )
 -r, --recall           Increase recall by parsing ambiguous affixes; may lower
     --skip-comments    Skip commented-out lines, without printing them
 -s, --stem             Return only word stems
 -t, --tokenize {0|1}   Tokenize punctuation (default: 1 == true)
 -u, --unvowel          Remove short vowels
 -v, --version          Print version
 -z, --zwnj {0|1}       Insert Zero Width Non-Joiners where they should be (default: 1 == true)


Thanks to Jace Livingston, David Zajic, and Corey Miller for their comprehensive error analysis and other suggestions. Thanks to Jay Ritch and Artyom Lukanin for spotting bugs.


If you use this software please cite the following

Dehdari, Jon, and Deryle Lonsdale. 2008. A link grammar parser for Persian. In Karimi, S., Samiian, V., and Stilo, D., editors, Aspects of Iranian Linguistics, volume 1. Cambridge Scholars Press. ISBN: 978-18-471-8639-3 (BibTeX)

Jadidinejad, Amir Hossein, Fariborz Mahmoudi, and Jon Dehdari. 2010. Evaluation of Perstem: A Simple and Efficient Stemming Algorithm for Persian. In Peters, C., Nunzio, G. D., Kurimo, M., Mandl, T., Mostefa, D., Peñas, A., and Roda, G., editors, Multilingual Information Access Evaluation I. Text Retrieval Experiments, volume 6241 of Lecture Notes in Computer Science, pages 98–101. Springer, Heidelberg. (BibTeX)


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