Defining a list of strings using snowball

Question

How can i define a list string using snowball ?

I have tried to do it like this :

define patterns ( 
      '{m}{f}{i}{l}' or '{f}{a}{i}{l}' or ....... 
)

How to get the list length ? how to deal with every pattern ?

Answer 1

An example:

groupings ( v v_WXY valid_LI )

stringescapes {}

define v        'aeiouy'
define v_WXY    v + 'wxY'

define valid_LI 'cdeghkmnrt'

Combine strings into groupings. Example drawn from: http://snowball.tartarus.org/algorithms/english/stemmer.html