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-- Copyright (C) 1995 by International Computer Science Institute            --
-- This file is part of the GNU Sather library. It is free software; you may --
-- redistribute  and/or modify it under the terms of the GNU Library General --
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-- WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITY --
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-------------->  Please email comments to <bug-sather@gnu.org>  <--------------

-- arr.sa: Simple algorithms for array structures
-- Author: Benedict A. Gomes <gomes@tiramisu.ICSI.Berkeley.EDU>

-- $ARR{ETP}    : Array abstraction
-------------------------------------------------------------------
abstract class $RO_ARR{ETP} < $CONTAINER{ETP} is
   -- A read-only array which is the interface to other algorithm classes
   
   ind!: INT;
   -- post 0<=result<size
   -- Returns all the indices, which are the integers between 0 and size - 1 

   aget(i: INT): ETP;
   -- pre has_ind(i)

   has_ind(i: INT): BOOL;
   -- return 0<=i<size
   -- This method could actually be implemented at this level

end;
-------------------------------------------------------------------
abstract class $ARR{ETP} < $RO_ARR{ETP} is
   -- The indices are integers and lie in [0, size-1]
   -- Similar to a MAP from ints to elements, but more restrictive conditions
   -- The features are repeated here so as to restate the preconditions
   -- Inherits: copy, size, capacity, elt! and has
   -- size: INT;
   -- elt!: ETP;
   -- has(e: ETP): BOOL;
   
   ind!: INT;
   -- post 0<=result<size
   -- Returns all the indices, which are the integers between 0 and size - 1 

   aget(i: INT): ETP;
   -- pre has_ind(i)
   
   aset(ind: INT,e: ETP);
   -- pre has_ind(i)
   
    copy: SAME;
    -- Redefined to narrow the return type
   
   has_ind(i: INT): BOOL;
   -- return 0<=i<size
   -- This method could actually be implemented at this level

end;
-------------------------------------------------------------------   
