sctabl (2) --- scan all symbols in a symbol table        01/07/83


            _C_a_l_l_i_n_g _I_n_f_o_r_m_a_t_i_o_n

                 integer function sctabl (table, symbol, info, posn)
                 pointer table, posn
                 untyped info (ARB)
                 character symbol (ARB)

                 Library:  vswtlb (standard Subsystem library)


            _F_u_n_c_t_i_o_n

                 'Sctabl'  provides  a means of accessing all symbols present
                 in a symbol table (c.f.  'mktabl') without knowledge of  the
                 table's  internal  structure.  After a simple initialization
                 (see below), successive calls to 'sctabl' return symbols and
                 their associated information.   When  the  return  value  of
                 'sctabl' is EOF, the entire table has been scanned.

                 The  first  argument  is the index in dynamic storage of the
                 symbol table to be accessed.   (This  should  be  the  value
                 returned by 'mktabl'.)

                 The second and third arguments receive the character text of
                 and integer information associated with the symbol currently
                 under scan.

                 The  fourth  argument  is  used to keep track of the current
                 position in the symbol table.  It  must  be  initialized  to
                 zero  before  'sctabl'  is  called  for the first time for a
                 given scan.  Furthermore, if the  scan  must  be  terminated
                 early (before 'sctabl' returns EOF) the dynamic storage area
                 pointed  to by this argument must be freed, e.g.  with "call
                 dsfree (posn)".

                 The function return is EOF when the entire  table  has  been
                 scanned, and not EOF otherwise.


            _I_m_p_l_e_m_e_n_t_a_t_i_o_n

                 If  'posn'  is zero, 'sctabl' allocates two words of dynamic
                 memory and assigns their location to it.   These  words  are
                 used to keep track of (1) the hash table bucket currently in
                 use  and  (2)  the position in the bucket's list of the next
                 symbol.  If a symbol  is  available  in  the  current  list,
                 'sctabl'  returns  its  data and records the position of the
                 next symbol in the list; otherwise, it  moves  to  the  next
                 bucket and examines that list.  If there are no more buckets
                 in  the symbol table, the position information pointed to by
                 'posn' is returned via a call to 'dsfree' and EOF is  retur-
                 ned  as  the function value.  Incidentally, 'posn' is set to
                 zero when the end of the table is encountered.





            sctabl (2)                    - 1 -                    sctabl (2)




            sctabl (2) --- scan all symbols in a symbol table        01/07/83


            _A_r_g_u_m_e_n_t_s _M_o_d_i_f_i_e_d

                 symbol, info, posn


            _C_a_l_l_s

                 dsget, dsfree, scopy


            _B_u_g_s

                 A call to 'enter' must be made  to  update  the  information
                 associated with a symbol.  If new symbols are entered or old
                 symbols  deleted  during  a  scan, the results are unpredic-
                 table.  The argument order is bogus; all  the  other  symbol
                 table routines have the table pointer as the last argument.


            _S_e_e _A_l_s_o

                 lookup  (2),  delete (2), mktabl (2), rmtabl (2), st$lu (6),
                 dsget (2), dsfree (2), dsinit (2)



































            sctabl (2)                    - 2 -                    sctabl (2)