def t_FIELD(t):
    r'[A-Za-z_][\w_]*'
    if t.value in u_ops:
        t.type = 'U_OP'
    elif t.value in b_ops:
        t.type = 'B_OP'
    return t
def t_FIELD ( t ) : if t . value in u_ops : t . type = 'U_OP' elif t . value in b_ops : t . type = 'B_OP' return t
r'[A-Za-z_][\w_]*