PROCEDURE  cjc_detab

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!  TPU procedure to replace tabs with spaces for the entire current buffer,
!  presuming that tabstops were  set at columns  1 , 9 , 17 , ...
!  ( i.e.,  mod ( tab-col , 8 )  =  1 )
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

LOCAL   where ,
        col ,
        end ;

ON_ERROR              !  deal with DEC's defective SEARCH that produces
ENDON_ERROR ;         !  silly "string not found" messages.

        position ( beginning_of (current_buffer ) ) ;

        loop
             where  :=  search ( ascii ( 9 ) , FORWARD ) ;
             exitif ( where = 0 ) ;
             position ( where ) ;
             col  :=  get_info ( mark ( NONE ) , "offset_column" ) ;

             end  :=  1 ;
             loop
                 end  :=  end + 8 ;
                 exitif ( end > col ) ;
             endloop ;

             erase ( where ) ;

             loop
                  copy_text ( ascii ( 32 ) ) ;
                  col  :=  col + 1 ;
                  exitif ( col >= end ) ;
             endloop ;

        endloop ;

ENDPROCEDURE ;