isClosure                package:nws                R Documentation

_i_s_C_l_o_s_u_r_e _F_u_n_c_t_i_o_n

_D_e_s_c_r_i_p_t_i_o_n:

     This is a heuristic function that is used by eachWorker and
     eachElem to guess if the worker function is a closure.

_D_e_t_a_i_l_s:

     If the "closure" option wasn't specified via the "eo" argument to
     eachWorker or eachElem, then this function is used to guess if the
     worker function is a closure.  It can be very useful to use a
     closures with eachWorker and eachElem, but if not used properly,
     you could accidentally include a lot of unnecessary data in the
     tasks, thus hurting your performance.

     This function is included as a development tool so you can
     manually test your worker functions.  This could be useful if you
     are getting a warning from eachWorker or eachElem, and are trying
     to determine how to modify the function or set the "closure"
     option.

_E_x_a_m_p_l_e_s:

     # this should return FALSE
     isClosure(sqrt)
     f <- function(x) function(y) x + y
     g <- f(1)
     # this should return TRUE
     isClosure(g)

