185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
+
+
+
+
+
-
+
+
|
-----------------------
-- Printer Interface --
-----------------------
overriding procedure Open_List (Output : in out Reference) is
begin
if Output.Exp.Is_Empty then
Output.Exp.Replace (Create_Tree'Access);
end if;
Output.Exp.Update.Data.Append (List_Node);
end Open_List;
overriding procedure Append_Atom
(Output : in out Reference; Data : in Atom) is
begin
if Output.Exp.Is_Empty then
Output.Exp.Replace (Create_Tree'Access);
end if;
Output.Exp.Update.Data.Append (Atom_Node, new Atom'(Data));
end Append_Atom;
overriding procedure Close_List (Output : in out Reference) is
begin
if not Output.Exp.Is_Empty then
Output.Exp.Update.Data.Close_List;
Output.Exp.Update.Data.Close_List;
end if;
end Close_List;
-------------------------
-- Reading Subprograms --
-------------------------
|