Spelling Corrector in Haskell
Haskell implementation (outlined in a blog post) of the simple spelling corrector
spell.py by Peter Norvig, which he describes in detail in the excellent essay "How to Write a Spelling Corrector". Any credit should go to him!
git clone https://github.com/doersino/spell.git cd spell cabal sandbox init cabal install
If you prefer using Stack, run
stack install instead of that Cabal nonsense.
For taking a first look, run
cabal repl or
stack ghci. Some examples:
*Spell> correction "scandinaiva" "scandinavia" *Spell> correction "inndeed" "indeed" *Spell> correction "photograf" "photograph"
- Performance is somewhat lacking. If you manage to significantly improve performance or reduce dependencies without major structural modifications (or just add more unit tests), please don't hesitate before filing an issue or sending a pull request.
- Haskell is lazy, so it won't parse the
big.txtfile until you call
correction. As a result, the first correction might take a few seconds -- subsequent ones will be faster.
- If you want, you can use this Cabal package as a dependency in your project (of course, there are better spell checkers). Since it's not on Hackage, run
cabal sandbox add-source <path to local clone of spell package>in your project directory before adding
build-dependslist in your
- In case you modify or replace
big.txt: the changes may not take effect until you re-run
cabal install. That's because it's listed in the
spell.cabal, enabling Cabal to provide an absolute path to
big.txtat runtime, which is helpful if you want to use the
spellpackage as a library or from any path on your system.
- If you want to be able to run the included Hspec unit tests, replace the
cabal installstep above with
cabal install --enable-tests. Run the tests by means of
cabal testor, for incremental and more colorful output,
cabal exec -- runhaskell -isrc -itest test/Spec.hs. If you're using Stack, simply run
stack haddockto generate documentation.