nwsIFetch                package:nws                R Documentation

_I_t_e_r_a_t_e _T_h_r_o_u_g_h _V_a_l_u_e_s _i_n _a _n_e_t_W_o_r_k_S_p_a_c_e _V_a_r_i_a_b_l_e

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

     Create a function that acts as a destructive iterator over the
     values of the specified variable.

_U_s_a_g_e:

     ## S4 method for signature 'netWorkSpace':
     nwsIFetch(.Object, xName)

_A_r_g_u_m_e_n_t_s:

 .Object: a netWorkSpace class object.

   xName: character string specifying name of the variable to be
          fetched

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

     The iterator function returned by the 'nwsIFetch' method takes no
     arguments, and works just like the 'nwsFetch' method, specified
     with the same arguments that were passed to 'nwsIFetch' method.
     Note that the 'nwsIFind' and 'nwsIFindTry' methods are much more
     useful, since they provide the only way to iterate over values of
     a variable non-destructively. The 'nwsIFetch' and 'nwsIFetchTry'
     methods are provided for completeness.

_S_e_e _A_l_s_o:

     'nwsFetch', 'nwsIFetchTry'

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

     ## Not run: 
     ws <- netWorkSpace('nws example')
     nwsStore(ws, 'x', 10)
     it <- nwsIFetch(ws, 'x')
     it()  # returns the value 10
     it()  # blocks until another process stores a value in the variable
     ## End(Not run)

