SClassExtension-class        package:methods        R Documentation

_C_l_a_s_s _t_o _R_e_p_r_e_s_e_n_t _I_n_h_e_r_i_t_a_n_c_e (_E_x_t_e_n_s_i_o_n) _R_e_l_a_t_i_o_n_s

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

     An object from this class represents a single ``is'' relationship;
     lists of these objects are used to represent all the extensions
     (superclasses) and subclasses for a given class.  The object
     contains information about how the relation is defined and methods
     to coerce, test, and replace correspondingly.

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects from this class are generated by `setIs', both from direct
     calls

_S_l_o_t_s:

     `_s_u_p_e_r_C_l_a_s_s': The name of the class being extended. 

     `_p_a_c_k_a_g_e': The package to which that class belongs. 

     `_c_o_e_r_c_e': A function to carry out the as() computation implied by
          the relation.  Note that these functions should not be used
          directly.  They only deal with the `strict=TRUE' calls to the
          `as' function, with the full method constructed from this
          mechanically. 

     `_t_e_s_t': The function that would test whether the relation holds. 
          Except for explicitly specified `test' arguments to `setIs',
          this function is trivial. 

     `_r_e_p_l_a_c_e': The method used to implement `as(x, Class) <- value'.

     `_s_i_m_p_l_e': A `"logical"' flag, `TRUE' if this is a simple relation,
          either because one class is contained in the definition of
          another, or because a class has been explicitly stated to
          extend a virtual class.  For simple extensions, the three
          methods are generated automatically.

     `_b_y': If this relation has been constructed transitively, the
          first intermediate class from the subclass. 

     `_d_a_t_a_P_a_r_t': A `"logical"' flag, `TRUE' if the extended class is in
          fact the data part of the subclass.  In this case the
          extended class is a basic class (i.e., a type). 

_M_e_t_h_o_d_s:

     No methods defined with class "SClassExtension" in the signature.

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

     `is', `as' and `classRepresentation-class'.

