'A list of rules based on context (preceding and following words).'

def __init__(self, path=''):

    self._path = path
    self._cmd = set(('prevtag', 'nexttag', 'prev2tag', 'next2tag', 'prev1or2tag', 'next1or2tag', 'prev1or2or3tag', 'next1or2or3tag', 'surroundtag', 'curwd', 'prevwd', 'nextwd', 'prev1or2wd', 'next1or2wd', 'next1or2or3wd', 'prev1or2or3wd', 'prevwdtag', 'nextwdtag', 'wdprevtag', 'wdnexttag', 'wdand2aft', 'wdand2tagbfr', 'wdand2tagaft', 'lbigram', 'rbigram', 'prevbigram', 'nextbigram'))
