def ft_emb(data, i, cols, rel=0, j=0, e=None, *args, **kwargs):
    """Generates features from word embeddings based on the `form` column.

    See links for more details on data resource format:

        http://metaoptimize.com/projects/wordreprs/
        https://code.google.com/p/word2vec/

    GOTCHA: some resources come with separators of 4 space characters
    (replacing a tab?), while the default is a single space.

    :param data: data
    :type data: DataFrame
    :param i: index
    :type i: int
    :param cols: column map
    :type cols: dict
    :param c: clusters
    :type c: dict
    :param rel: relative index
    :type rel: int
    :return: feature string
    :rtype: str
    """
    if 0 <= i + rel < len(data):
        try:
            emb = e[data[i + rel][cols['form']]][j]
        except KeyError:
            emb = None
    else:
        emb = None
    return 'emb[%s][%s]=%s' % (rel, j, emb)
