examples/legacy/seq2seq/run_eval_search.py/parse_search_arg
def parse_search_arg(search):
    groups = search.split()
    entries = {k: vs for k, vs in (g.split("=") for g in groups)}
    entry_names = list(entries.keys())
    sets = [[f"--{k} {v}" for v in vs.split(":")] for k, vs in entries.items()]
    matrix = [list(x) for x in itertools.product(*sets)]
    return matrix, entry_names