Department of Mathematics and Computer Science

Math 169

Ada Information

D. C. Smolarski, S.J.

Contents

• Ada on the Dec Alpha Server
• Sample Ada Source Code
• Sample Execution

Ada on the Dec Alpha Server

1. General information is given in the Dec User's Guide for running ADA programs.

2. Create a source code (program) file using an editor of your choice (e.g., Emacs or other available VMS editor, such as LSE). The extension should be .ADA

3. After the source code file is created, execution of the code is via a modified sequence of steps, resembling the standard procedure for other languages, but with several significant differences. You must first create a proper ADA library via the command:

             ACS CREATE LIBRARY [JSMITH.ADALIB]
   

   Then you set the library via the command:

             ACS SET LIBRARY [JSMITH.ADALIB]
   

   Setting the library must be done for every login session (you can insert this command into your LOGIN.COM file), although the library directory need only be created once. Linking is done via ACS, as in the following example:

   	[JDOE]> ADA MPADA
   	[JDOE]> ACS LINK MPADA
   	[JDOE]> RUN MPADA
   

4. A sample run of an Ada program on the Alpha is given in below.

Sample Ada Source Code

     
With Text_IO; 
Use Text_IO;

Package Int_IO is new Integer_IO(integer);
with int_IO;
use Int_IO;

Procedure Point is

--The following line can also be used in some versions of ADA as the
--header line.
--Package Body Point Is

type node;

type tree is access node;

type node is record
              left : tree;
              info : integer;
              right: tree;
            end record;

     count:integer;  --(* counts the recursive level. *)
     numnode:integer;--(* counts the number of nodes created. *)
     root:tree;

-- The following instantiation of Integer_IO (contained in
-- Text_IO) is standard.  However, in the PC Janus/Ada version,
-- it is not necessary.  This process of INSTANTIATION takes the
-- generic template for IO functions, and makes an actual version
-- of it with Integer as the data type used.

Package Int_IO is new Integer_IO(Integer);
Use Int_IO;

--(* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *)
--(*       F U N C T I O N   G E N T R E E                   *)
--(*     This generates a tree.  n is a small positive integer
--	specifying an upper bound on the number of nodes
--	of the tree.  The nodes can have two children, and
--	an information field.  The information field is 
--	given a sequential node number.                    *)

function gentree(n:integer) return tree is
   t : tree;
BEGIN
   numnode := numnode + 1;
   t := new node'(null,numnode,null);
   IF n <=2 THEN t.left := null;
            ELSE t.left := gentree(n / 2);
   End If;
   IF n <= 2 THEN t.right := null;
             ELSE t.right := gentree(n / 2);
   End If;
   return(t);
END;
--(* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *)
--(*       P R O C E D U R E   T R E E P R I N T            *)
--(*	The information fields of the nodes of a tree
--	are printed so that the tree is rotated 90 degrees
--	counter-clockwise.  The nodes are given proper 
--	depths.                                          *)

PROCEDURE treeprint (t:tree) is

BEGIN
   count := count + 1;
   IF t /= null THEN
           treeprint(t.right);
           FOR i in 1 .. count loop put("       "); End loop;
           Put(t.info); New_line;
           treeprint(t.left);
        END If;
   count := count - 1;
END;

BEGIN
   numnode := 0;  count := 0;  --(* initialization *)
   root := gentree(16);
   treeprint(root);
END point;

Sample Execution of an Ada Program on the Alpha

[DSMOLARSKI]> photo
[DSMOLARSKI]>  acs set library [dsmolarski.ada]
%ACS-I-CL_LIBIS, Current program library is FACULTY:[DSMOLARSKI.ADA]
[DSMOLARSKI]> ada point
[DSMOLARSKI]> acs link point
%ACS-I-CL_LINKING, Invoking the VAX/VMS Linker
[DSMOLARSKI]> run point
                                     15
                              13
                                     14
                        9
                                     12
                              10
                                     11
                 1
                                      8
                               6
                                      7
                        2
                                      5
                               3
                                      4
[DSMOLARSKI]> pop
  Process DSMOLARSKI_1 logged out at  3-FEB-1988 21:34:43.03

My email address is dsmolarski@math.scu.edu

This page last updated 25 March 2000.