(none)

[jduarte@siam.ICS.UCI.EDU (Jose_Duarte)]

Hello Folks,

	I am currently writing a routine in Ada under Berkeley Unix 4.2
using the Verdix ADA compiler 6.0.  I am using the standard Text_IO
routines GET and PUT to implement a function to save a tree in text
format.  I save the tree using a depth-first algorithm, and this means
that I have to call the Save_Tree function recursively...I am using a
Sun 4 machine to work on, and I get a BUS ERROR once in a while...No
exceptions are raised...just a BUS ERROR...It doesn't happen always,
and my routine doesn't "bite the dust" in the same place when I do
get a BUS ERROR...My question is: Has anyone else had the same problem ?
I know this is too general a question, but I just thought I'd ask...

Jose Duarte.
------------------------------------------------------
CODE:

with Lines,
     Text_IO,
     Tree_Generation,
     File_Manager,
     Command_Line,
     CTA_System,
     Tables;






package body Tree_Traversal is






------------------------------------------------------
-- procedure Print_Tree_2
--
-- This procedure Prints out the Classification Tree
-- using a depth-first recursive algorithm.  The User's
-- Manual displays a Tree and a sample tree ouput. If
-- The Indentation_Level is too long, then the output
-- will be messed up. Tough Luck !!!
--
-- There are three cases possible when Printing the tree:
--
-- 1. The Node_Ptr parameter is null.
--         The words "null node" are ouput
--
-- 2. The Node_Ptr parameter points to a terminal node:
--         The Node classification is determined from the
--         node record field "Classification", and then the
--         symbols <+> or <-> or <*> are output.
--
-- 3. The Node_Ptr points to a NONTERMINAL record node:
--         The Metric Name is extracted from the Metrics
--         Table according to the "Metric_Code" field in the
--         record.  Next, the Arc_List pointer is initialized
--         to point to the first arc.  A "while" loop calls
--         the Print_Tree procedure recursively for each arc
--         in the arcs_list with a new Indentation_Level.
--
------------------------------------------------------
procedure Print_Tree_2(F                : Text_IO.File_Type;
                       Node_Ptr         : Tree_Generation.Tree_Node_Pointer;
                       Indentation_Level: Natural ) is

use File_Manager,CTA_System,Tree_Generation,Text_IO;
Arc_List : Tree_Arc_Pointer;

Metric_Type: Tables.Value_Type;
Metric_Code: POSITIVE;
Temp_Str   : Lines.Normal_Line;
Int1,Int2  : INTEGER;
F1,F2      : FLOAT;

begin
   New_Line(F);
   -- indent the proper number of columns:
   For X in NATURAL range 1..Indentation_Level loop
       Put(F,'|');
   end loop;


   -- case 1: The pointer is a null pointer
   if (Node_Ptr = null) then
      Put(F,"<null node>");
      return;
   end if;


   -- case 2: The pointer points to a terminal node
   if (Is_Terminal(Node_Ptr)) then
      case Return_Classification(Node_Ptr) is
          when CTA_System.P => Put(F,"<+>");
          when CTA_System.N => Put(F,"<->");
          when CTA_System.Z => Put(F,"<Z>");
          when CTA_System.M => Put(F,"<M>");
          when CTA_System.D => Put(F,"<D>");
          when CTA_System.U => Put(F,"<U>");
      end case;
      -- New_Line(F);
      return;
   end if;

   -- case 3: a NONTERMINAL
   -- it's not null and not a terminal
   -- i.e. it's a nonterminal:

   -- put out Metric Name - a conversion is required:
   Put(F,Lines.IMAGE(Get_Metric_Name(Return_Metric_Code(Node_Ptr))));
   -- New_Line(F);

   -- start off with the first child node:
   Arc_List := Get_Arc_List_Pointer(Node_Ptr);

   Metric_Type := Get_Metric_Type(Return_Metric_Code(Node_Ptr));
   while (Arc_List /= null) loop
       Get_Range_Values(Arc_List,Temp_Str,Int1,Int2,F1,F2);
       if NOT (Is_Terminal(Get_Child_Node_From_Arc(Arc_List))) then
       New_Line(F);
       For X in NATURAL range 1..Indentation_Level+4 loop
          Put(F,' ');
       end loop;
       case Metric_Type is
         when Tables.CHAR  =>
              Put(F," ( " & Lines.IMAGE(Temp_Str) & " ) ");
         when Tables.INT   =>
              Put(F, " ( ");
              Put(F, INTEGER'IMAGE(Int1));
              Put(F," , ");
              Put(F, INTEGER'IMAGE(Int2));
              Put(F, " ) ");
         when Tables.REAL  =>
              Put(F, " ( ");
              CTA_System.CTA_Floats.Put(F,F1,1,3,3);
              Put(F," , ");
              CTA_System.CTA_Floats.Put(F, F2,1,3,3);
              Put(F, " ) ");
         end case;
       end if;
       Print_Tree_2(F,Get_Child_Node_From_Arc(Arc_List), Indentation_Level+5);

       if (Is_Terminal(Get_Child_Node_From_Arc(Arc_List))) then
       case Metric_Type is
         when Tables.CHAR  =>
              Put(F," ( " & Lines.IMAGE(Temp_Str) & " ) ");
         when Tables.INT   =>
              Put(F, " ( ");
              Put(F, INTEGER'IMAGE(Int1));
              Put(F," , ");
              Put(F, INTEGER'IMAGE(Int2));
              Put(F, " ) ");
         when Tables.REAL  =>
              Put(F, " ( ");
              CTA_System.CTA_Floats.Put(F,F1,1,3,3);
              Put(F," , ");
              CTA_System.CTA_Floats.Put(F, F2,1,3,3);
              Put(F, " ) ");
       end case;
       -- New_Line(F);
       end if;
       Arc_List := Next_Arc(Arc_List);
   end loop;
end Print_Tree_2;





------------------------------------------------------
procedure Print_Tree(Node_Ptr         : Tree_Generation.Tree_Node_Pointer;
                     Indentation_Level: Natural := 0) is
use Text_IO;

F: File_Type;

begin
   -- Get the output filename from the command-line:
   Lines.Assign(CTA_System.Filename,Command_Line.argv(2).s);
   CREATE(F,Out_File,Lines.IMAGE(CTA_System.Filename));
   -- Save the tree to a file:
   Print_Tree_2(F,Node_Ptr,Indentation_Level);
   CLOSE(F);
end;





end Tree_Traversal;