SFST

SFST (Stuttgart Finite State Toolkit) is a set of programs that can be used for writing morphological analysers. It is also one of the possible backends for HFST.

Installation

Prerequisites

On Ubuntu/Debian:

sudo apt-get install libreadline-dev

Download, compile, install

 wget ftp://ftp.ims.uni-stuttgart.de/pub/corpora/SFST/SFST-1.4.6g.tar.gz
 tar -xzvf SFST-1.4.6g.tar.gz
 cd SFST/src
 make
 sudo make install
 sudo make libinstall

Note: on Arch Linux, you may have to do make clean && make CFLAGS=-fPIC instead of make.

Usage

To try SFST out, you can start by compiling the German transducer, SMOR, that comes with the package:

$ cd data/SMOR
$ make

Wait some time, and you will have a file called smor.a, now you need to compact this so it can be read by fst-proc,

$ fst-compact smor.a smor.ac

Now you can use it,

$ cd ../../src
$ echo "Ich habe ein Bier" |  fst-proc ../data/SMOR/smor.ac
^Ich/<CAP>ich<+PPRO><pers><1><Sg><NoGend><Nom>$ 
^habe/haben<+V><1><Sg><Pres><Konj>/haben<+V><3><Sg><Pres><Konj>/haben<+V><Imp><Sg>/haben<+V><1><Sg><Pres><Ind>$ 
^ein/ein<+ART><Indef><Masc><Nom><Sg>/ein<+ART><Indef><Neut><Nom><Sg>/ein<+ART><Indef><Neut><Akk><Sg>$ ^Bier/*Bier$

It should also work with deformatters and reformatters,

$ echo "Ich habe <em>ein</em> bier" | apertium-deshtml  |  ./fst-proc ../data/SMOR/smor.ac
^Ich/<CAP>ich<+PPRO><pers><1><Sg><NoGend><Nom>$ 
^habe/haben<+V><1><Sg><Pres><Konj>/haben<+V><3><Sg><Pres><Konj>/haben<+V><Imp><Sg>/haben<+V><1><Sg><Pres><Ind>$[ 
<em>]^ein/ein<+ART><Indef><Masc><Nom><Sg>/ein<+ART><Indef><Neut><Nom><Sg>/ein<+ART><Indef><Neut><Akk><Sg>$[<\/em> ]^Bier/*Bier$.[][

Note: fst-proc currently does a rather crude tokenisation based on spaces, so multiwords currently aren't possible.

Morphologies

SFST has the following morphologies available for download:

• Morph-IT! (Italian, 34,968 lemmas, LGPL)
• Omorfi–SFST implementation of word form morphology of Finnish (Finnish, 93,510 lemmas, LGPL)
  • For further information see: Omorfi
• SMOR — comes in the SFST distribution (German, 1,096 lemmas, GPL)
• trmorph (Turkish, wide coverage)
  • For further information see: Turkish

Performance

The analysers produced are fast. For a 1.3Mb analyser (SMOR), it processes ~1,100 words per second. Compare with lttoolbox which processes ~5,000 words per second.

External links

• SFST - Stuttgart Finite State Transducer Tools