-- Item :      Simple Search Procedure
-- Reference : Data Structures and Program Design, Pascal, p 244.
-- Author :    Kruse, recoded by Paul Stachour, stachour@winternet.com
-- Version :   1.0, 1999/Jan/12
-- For :       ICS340, Winter 199, Metro State, Minnesota
-- Style :     Ada95, in a pascalish style, to match the textbook.
-- Protection: Original copyright 1994, Prentice Hall
-- Derivation: Derivation by permission; see Author for details

procedure ch7_ss is             -- demo procedure to drive example.

-- types and constants for the driver.
type key_type is new integer;   -- For the demo, keys are integers
subtype Position is Natural;    -- Descrete for type-safety
type list_entry is              -- An entry in the list.
  record
     key: key_type;
     data: integer;
  end record;

type list is array(Position range <>) of list_entry;

ss_list: list := ( 
  (key => 1, data => 3),
  (key => 2, data => 3),
  (key => 3, data => 7),
  (key => 101, data => 32767) );

Is_Found : BOOLEAN := False;
Where    : Position;

procedure sequential_search
  (L: in list;                  -- The list to be searched
   Target: in Key_Type;         -- The target of the search
   Found: out BOOLEAN;          -- Was the search successful?
   Location: out Position) is   -- Where in list if successful
-- Pre : The contiguous list L has been created
-- Post: In an entry in L has key equal to target, then Found becomes
--       TRUE and Location contains the position of such entry. Otherwise
--       Found becomes False and Location becomes invalid.
begin
  Found := False;
  for Loc in L'Range loop       -- We loop through range of possibilities
    if L(lOC).Key = Target then -- Did we find it?
      Found := TRUE;
      Location := Loc;
      exit;                    -- Yes, so indicate and exit
    end if;
  end loop;
end Sequential_Search;

begin
  Sequential_Search
    (L => ss_list, Target => 3, Found => Is_Found, Location => Where);
  Sequential_Search
    (L => ss_list, Target => 101, Found => Is_Found, Location => Where);
  Sequential_Search
    (L => ss_list, Target => 237, Found => Is_Found, Location => Where);

end ch7_ss;