from pydsl.File.BNF import load_bnf_file
grammardefinition = loand_bnf_file('myfile.bnf')
grammardefinition.alphabet # Returns the alphabet used by this grammar
grammardefinition.minsize
grammardefinition.maxsize 
grammardefinition.enumerate # Returns a generator that generates every accepted word

from pydsl.Checker import check
check(grammardefinition,'mystring') # returns True or False

from pydsl.Parser import parse
parse(grammardefinition,'mystring') # returns a ParseTree

from pydsl.Extract import extract
extract(grammardefinition,'abcmystringabc') # returns ('mystring',3,11)