Aminet 30/Aminet 30 (1999)(Schatztruhe)[!][Apr 1999].iso/Aminet/dev/lang/SmallEiffel.lha/SmallEiffel/lib_std/array.e

Text File | 1998-12-22 | 8KB | 316 lines

-- This file is  free  software, which  comes  along  with  SmallEiffel. This
-- software  is  distributed  in the hope that it will be useful, but WITHOUT
-- ANY  WARRANTY;  without  even  the  implied warranty of MERCHANTABILITY or
-- FITNESS  FOR A PARTICULAR PURPOSE. You can modify it as you want, provided
-- this header is kept unaltered, and a notification of the changes is added.
-- You  are  allowed  to  redistribute  it and sell it, alone or as a part of
-- another product.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - [e-mail]
--                       http://www.loria.fr/SmallEiffel
--
class ARRAY[E]
   --
   -- General purpose resizable ARRAYs.
   --

inherit ARRAYED_COLLECTION[E];

creation make, with_capacity, from_collection

feature

   lower: INTEGER;
     -- Lower index bound.

feature -- Creation and Modification :

   make(minindex, maxindex: INTEGER) is
     -- Make array with range [`minindex' .. `maxindex'].
     -- When `maxindex' = `minindex' - 1, the array is empty.
      require
     minindex -1 <= maxindex
      local
     needed: INTEGER;
      do
     lower := minindex;
     upper := maxindex;
     needed := maxindex - minindex + 1;
     if needed > 0 then
        if capacity < needed then
           storage := storage.calloc(needed);
           capacity := needed;
        else
           clear_all;
        end;
     end;
      ensure
     lower = minindex;
     upper = maxindex;
     all_cleared
      end;

   with_capacity(needed_capacity, low: INTEGER) is
     -- Create an empty array with `capacity' initialized
     -- at least to `needed_capacity' and `lower' set to `low'.
      require
     needed_capacity >= 0
      do
     if capacity < needed_capacity then
        storage := storage.calloc(needed_capacity);
        capacity := needed_capacity;
     end;
     lower := low;
     upper := low - 1;
      ensure
     empty;
     needed_capacity <= capacity;
     lower = low
      end;

feature -- Modification :

   resize(minindex, maxindex: INTEGER) is
     -- Resize the array. No elements will be lost in the
     -- intersection of [old `lower' .. old `upper'] and
     -- [`minindex' .. `maxindex'].
     -- New positions are initialized with appropriate
     -- default values.
      require
         minindex -1 <= maxindex
      local
         needed, offset, intersize: INTEGER;
      do
         needed := maxindex - minindex + 1;
         if needed > 0 then
            if needed > capacity then
               if capacity = 0 then
                  storage := storage.calloc(needed);
                  capacity := needed;
               else
                  storage := storage.realloc(capacity, needed);
                  capacity := needed;
               end;
            end;
            offset := lower - minindex;
            intersize := maxindex.min(upper) - minindex.max(lower) + 1;
            if intersize > 0 then
               if offset = 0 then
                  if intersize < needed then
                     storage.clear(intersize, needed - 1);
                  end;
               elseif offset < 0 then
                  storage.move(-offset, intersize - offset - 1, offset);
                  if intersize < needed then
                     storage.clear(intersize, needed - 1);
                  end;
               else
                  storage.move(0, intersize - 1, offset);
                  storage.clear(0, offset - 1);
                  if intersize + offset < needed then
                     storage.clear(intersize + offset, needed - 1);
                  end;
               end;
            else
               storage.clear(0, needed - 1);
            end;
         end;
         lower := minindex;
         upper := maxindex;
      end;

feature

   sub_array(low, up: INTEGER): like Current is
      local
     i: INTEGER;
      do
     from
        !!Result.with_capacity(up - low + 1,low);
        Result.set_upper(up);
        i := low;
     until
        i > up
     loop
        Result.put(item(i),i);
        i := i + 1;
     end;
      ensure then
     Result.lower = low;
      end;

feature -- Implementation of deferred :

   count: INTEGER is
      do
     Result := upper - lower + 1;
      end;

   item, infix "@" (index: INTEGER): E is
      do
     Result := storage.item(index - lower);
      end;

   put(element: like item; index: INTEGER) is
      do
     storage.put(element,index - lower);
      end;

   force(element: like item; index: INTEGER) is
     -- Put `element' at position `index'. Current is
     -- resized if `index' is not inside current bounds.
     -- New bounds are initialized with default values.
      require else
     true
      do
     if upper < index then
        resize(lower,index);
     elseif index < lower then
        resize(index,upper);
     end;
     put(element,index);
      end;

   copy(other: like Current) is
      local
     needed_capacity: INTEGER;
      do
     lower := other.lower;
     upper := other.upper;
     needed_capacity := upper - lower + 1;
     if capacity < needed_capacity then
        capacity := needed_capacity;
        storage := storage.calloc(capacity);
     end;
     if needed_capacity > 0 then
        storage.copy_from(other.storage,needed_capacity - 1);
     end;
      end;

   set_all_with(v: like item) is
      do
     storage.set_all_with(v,upper - lower);
      end;

   remove_first is
      do
     storage.remove_first(upper - lower);
     lower := lower + 1;
      ensure then
     upper = old upper;
      end;

   remove(index: INTEGER) is
      do
     storage.remove(index - lower,upper - lower);
     upper := upper - 1;
      end;

   clear is
      do
     upper := lower - 1;
      ensure then
     capacity = old capacity
      end;

   add_first(element: like item) is
      do
     if upper < lower then
        add_last(element);
     else
        add_last(element);
        move(lower,upper - 1,1);
        put(element,lower);
     end;
      end;

   add_last(element: like item) is
      local
     new_capacity: INTEGER;
      do
     if capacity < count + 1 then
        if capacity = 0 then
           capacity := 16;
           storage := storage.calloc(capacity);
        else
           new_capacity := 2 * capacity;
           storage := storage.realloc(capacity,new_capacity);
           capacity := new_capacity;
        end;
     end;
     upper := upper + 1;
     put(element,upper);
      end;

   from_collection(model: COLLECTION[like item]) is
      local
     i, up: INTEGER;
      do
     from
        with_capacity(model.count,model.lower);
        i := model.lower;
        up := model.upper;
        upper := up;
     until
        i > up
     loop
        put(model.item(i),i);
        i := i + 1;
     end;
      ensure then
     lower = model.lower;
     upper = model.upper
      end;

   all_cleared: BOOLEAN is
      do
     Result := storage.all_cleared(upper - lower);
      end;

   nb_occurrences(element: like item): INTEGER is
      do
     Result := storage.nb_occurrences(element,upper - lower);
      end;

   fast_nb_occurrences(element: like item): INTEGER is
      do
     Result := storage.fast_nb_occurrences(element,upper - lower);
      end;

   index_of(element: like item): INTEGER is
      do
     Result := lower + storage.index_of(element,upper - lower);
      end;

   fast_index_of(element: like item): INTEGER is
      do
     Result := lower + storage.fast_index_of(element,upper - lower);
      end;

   is_equal(other: like Current): BOOLEAN is
      do
     if Current = other then
        Result := true;
     elseif lower = other.lower and then upper = other.upper then
        Result := storage.memcmp(other.storage,count);
     end;
      end;

   slice(low, up: INTEGER): like Current is
      local
     i: INTEGER;
      do
     from
        i := low;
        !!Result.with_capacity(up - low + 1,lower);
     until
        i > up
     loop
        Result.add_last(item(i));
        i := i + 1;
     end;
      end;

end -- ARRAY[E]