Classifying the parts of speech of words

This recipe will demonstrate how to identify the parts of speech of each word in a sentence. We will be using a handy library called chatter, which contains very useful Natural Language Processing (NLP) tools. It can be obtained from Hackage at http://hackage.haskell.org/package/chatter.

NLP is the study of human language embedded in a machine. Our naturally spoken or written language may seem obvious to us in our day-to-day lives, but producing meaning out of words is still a difficult task for computers.

Getting ready

Install the NLP library using cabal:

cabal install chatter

How to do it…

In a new file, which we name Main.hs, enter the following source code:

1. Import the parts of speech library and the pack function:

   import NLP.POS
   import Data.Text (pack)

2. Obtain the default tagger provided by the library:

   main = do
   tagger <- defaultTagger

3. Feed the tag function a tagger and a text to see the corresponding parts of speech per each word:

   let text =...