def _hgvs_coord_to_ci(s, e):
def _hgvs_to_ci(c):<EOL><INDENT>assert c != <NUM_LIT:0>, "<STR_LIT>"<EOL>return c - <NUM_LIT:1> if c > <NUM_LIT:0> else c<EOL><DEDENT>return (None if s is None else _hgvs_to_ci(s), None if e is None else _hgvs_to_ci(e) + <NUM_LIT:1>)<EOL>
convert start,end interval in inclusive, discontinuous HGVS coordinates
    (..,-2,-1,1,2,..) to continuous interbase (right-open) coordinates
    (..,-2,-1,0,1,..)