{
History
-------

 13/02/86 - Add call to EpDiscard to dispose address descriptor in
	    Closewtih. New include file impint.pf
									}

{

                          MODULE 21


                       With Statements





 The set of records addressed by currently open with-statements  is
 held  as  a 'with-stack', pointed to by the variable TopWithEntry,
 and maintained by the procedures OpenWith and CloseWith.

 OpenWith creates an extended reference  to  the  record  variable,
 generates  code  if  necessary  to  save  its address in temporary
 storage, and pushes a new entry onto the  with-stack  holding  the
 variable  reference  and a unique 'with-base' key generated by the
 analyser.

 Subsequent calls to WithReference use the key  value  supplied  by
 the  analyser  to  locate the corresponding reference in the with-
 stack, and re-create it on the operand/reference stack for use  by
 the subsequent call to FieldReference.

 At the end of a with-statement the  procedure  CloseWith  releases
 any locks set by the extended reference and pops the with-stack.

                                                                     }

program WithStatements;
  
#include "globals.x"
#include "varref.pf"
#include "codeutils.pf"
#include "impint.pf"

  procedure OpenWith(WithBase: DispRange);
    visible;
    
    var
      LocalBase: StackEntry;
      ThisEntry: WithEntry;
    
    begin
      if CodeIsToBeGenerated
      then
        begin
          new(ThisEntry);
          with ThisEntry^ do
            begin
              BaseNum := WithBase;
              Pop(LocalBase);
              SaveAddress(LocalBase);
              Entry := LocalBase;
              Next := TopWithEntry
            end;
          TopWithEntry := ThisEntry
        end
    end { openwith };
  
  procedure WithReference(WithBase: DispRange);
    visible;
    
    var
      BaseEntry: WithEntry;
      NewBase: StackEntry;
    
    begin
      if CodeIsToBeGenerated
      then
        begin
          BaseEntry := TopWithEntry;
          while BaseEntry^.BaseNum <> WithBase do
            BaseEntry := BaseEntry^.Next;
          GetEntry(NewBase);
          NewBase^ := BaseEntry^.Entry^;
          Push(NewBase)
        end
    end { withreference };
  
  procedure CloseWith;
    visible;
    
    var ThisEntry: WithEntry;
    
    begin
      if CodeIsToBeGenerated
      then
        begin
          ThisEntry := TopWithEntry;
          with ThisEntry^ do
            begin
              with Entry^ do
		if Kind = Address then
		  if not Loaded then EpDiscard(Descriptor);
	      FreeEntry(Entry);
              TopWithEntry := Next
            end;
          dispose(ThisEntry)
        end
    end { closewith };
  
  procedure InitWith;
    visible;
    
    begin TopWithEntry := nil end;
  
  begin 
  { end of module }
  end.