-- This file is  free  software, which  comes  along  with  SmartEiffel. 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) 1994-2002 LORIA - INRIA - U.H.P. Nancy 1 - FRANCE
--          Dominique COLNET and Suzanne COLLIN - SmartEiffel@loria.fr
--                       http://SmartEiffel.loria.fr
--
class ARRAY2[E]
   --
   -- General prurpose, resizable, two dimensional array.
   --

inherit COLLECTION2[E]

creation
   make, copy, from_collection2, from_collection, from_model

feature

   lower1, lower2, upper1, upper2: INTEGER

feature {ARRAY2}

   storage: NATIVE_ARRAY[E]
         -- To store elements line by line.

   capacity: INTEGER
         -- Number of elements in `storage'.

feature -- Creation / modification:

   make(line_min, line_max, column_min, column_max: INTEGER) is
         -- Reset all bounds `line_minimum' / `line_maximum' / `column_minimum' and
         -- `column_maximum' using arguments as new values.
         -- All elements are set to the default value of type E.
      require
         line_min <= line_max
         column_min <= column_max
      do
         lower1 := line_min
         upper1 := line_max
         lower2 := column_min
         upper2 := column_max
         if capacity >= count then
            storage.clear_all(count - 1)
         else
            capacity := count
            storage := storage.calloc(count)
         end
      ensure
         line_minimum = line_min
         line_maximum = line_max
         column_minimum = column_min
         column_maximum = column_max
      end

   from_collection2(model: COLLECTION2[like item]) is
      local
         i, j: INTEGER
      do
         make(model.line_minimum,
              model.line_maximum,
              model.column_minimum,
              model.column_maximum)
         from
            i := line_minimum
         until
            i > line_maximum
         loop
            from
               j := column_minimum
            until
               j > column_maximum
            loop
               put(model.item(i,j),i,j)
               j := j + 1
            end
            i := i + 1
         end
      ensure then
         lower1 = model.lower1
         lower2 = model.lower2
      end

   from_collection(contents: COLLECTION[E]
                   line_min, line_max, column_min, column_max: INTEGER) is
         --  Reset all bounds using `line_min', `line_max', `column_min',
         --  and `column_max' .
         --  Copy all elements of `contents', line by line into Current.
      require
         line_min <= line_max
         column_min <= column_max
         contents.count = (line_max - line_min + 1) * (column_max - column_min +1)
      local
         i: INTEGER
      do
         make(line_min,line_max,column_min,column_max)
         from
            i := 0
         until
            i >= count
         loop
            storage.put(contents.item(contents.lower + i),i)
            i := i + 1
         end
      ensure
         line_minimum = line_min
         line_maximum = line_max
         column_minimum = column_min
         column_maximum = column_max
         count = contents.count
      end

   from_model(model: COLLECTION[COLLECTION[E]]) is
         -- The `model' is used to fill line by line the COLLECTION2.
         -- Assume all sub-collections of `model' have the same indexing.
      local
         line, column: INTEGER
      do
         make(model.lower,
              model.upper,
              model.first.lower,
              model.first.upper)
         from
            line := model.lower
         until
            line > model.upper
         loop
            from
               column := model.first.lower
            until
               column > model.first.upper
            loop
               put(model.item(line).item(column),line,column)
               column := column + 1
            end
            line := line + 1
         end
      ensure
         line_minimum = model.lower
         line_maximum = model.upper
         column_minimum = model.first.lower
         column_maximum = model.first.upper
      end

feature -- Resizing:

   resize(line_min, line_max, column_min, column_max: INTEGER) is
         -- Resize bounds of the Current array
      require
         line_max >= line_min
         column_max >= column_min
      local
         tmp: like Current
         l, c: INTEGER
      do
         !!tmp.make(line_min, line_max, column_min, column_max)
         -- It may be possible to avoid this ceation when :
         --    new `capacity' <= old `capacity'
         from
            l := lower1
         until
            l > line_maximum
         loop
            from
               c := lower2
            until
               c > column_maximum
            loop
               if tmp.valid_index(l,c) then
                  tmp.put(item(l,c),l,c)
               end
               c := c + 1
            end
            l := l + 1
         end
         standard_copy(tmp)
      ensure
         line_minimum = line_min
         line_maximum = line_max
         column_minimum = column_min
         column_maximum = column_max
      end

feature -- Implementation of others feature from COLLECTION2:

   item(line, column: INTEGER): E is
      do
         Result := storage.item((line - lower1) * count2 + column - lower2)
      end

   put(element: like item; line, column: INTEGER) is
      do
         storage.put(element,(line - lower1) * count2 + column - lower2)
      end

   count1: INTEGER is
      do
         Result := upper1 - lower1 + 1
      end

   count2: INTEGER is
      do
         Result := upper2 - lower2 + 1
      end

   count: INTEGER is
      do
         Result := count1 * count2
      end

   force(x: like item; line, column: INTEGER) is
      require
         true
      do
         if not valid_index(line,column) then
            resize(line.min(lower1),
                   line.max(upper1),
                   column.min(lower2),
                   column.max(upper2))
         end
         put(x,line,column)
      end

   set_all_with(element: E) is
      do
         storage.set_all_with(element,count - 1)
      end

   replace_all(old_value, new_value: like item) is
      do
         storage.replace_all(old_value,new_value,count - 1)
      end

   fast_replace_all(old_value, new_value: like item) is
      do
         storage.fast_replace_all(old_value,new_value,count - 1)
      end

   sub_collection2(line_min, line_max, column_min, column_max: INTEGER): like Current is
      require
         valid_index(line_min,line_max)
         valid_index(column_min,column_max)
      local
         i, j, k: INTEGER
      do
         !!Result.make(line_min,line_max,column_min,column_max)
         from
            i := line_min
            k := 0
         until
            i > line_max
         loop
            from
               j := column_min
            until
               j > column_max
            loop
               Result.storage.put(item(i,j),k)
               j := j + 1
               k := k + 1
            end
            i := i + 1
         end
      ensure
         Result.lower1 = line_min
         Result.lower2 = column_min
         Result.upper1 = line_max
         Result.upper2 = column_max
      end

feature --  Looking and comparison:

   occurrences(elt: E): INTEGER is
      do
         Result := storage.occurrences(elt,count - 1)
      ensure
         Result >= 0
      end

   fast_occurrences(elt: E): INTEGER is
      do
         Result := storage.fast_occurrences(elt,count - 1)
      ensure
         Result >= 0
      end

   has(x: like item): BOOLEAN is
         -- Search if a element x is in the array using `equal'.
         -- See also `fast_has' to chose the apropriate one.
      do
         Result := storage.index_of(x,count - 1) <= count - 1
      end

   fast_has(x: like item): BOOLEAN is
         --  Search if a element x is in the array using `='.
      do
         Result := storage.fast_index_of(x,count - 1) <= count -1
      end

   all_default: BOOLEAN is
      do
         result := storage.all_default(count - 1)
      end

   swap(line1, column1, line2, column2 : INTEGER) is
      local
         tmp: like item
         c2, index1, index2: INTEGER
      do
         c2 := count2
         index1 := (line1 - lower1) * c2 + column1 - lower2
         index2 := (line2 - lower1) * c2 + column2 - lower2
         tmp := storage.item(index1)
         storage.put(storage.item(index2),index1)
         storage.put(tmp,index2)
      end

   copy(other: like Current) is
      do
         lower1 := other.lower1
         upper1 := other.upper1
         lower2 := other.lower2
         upper2 := other.upper2
         if capacity < count then
            capacity := count
            storage := storage.calloc(count)
         end
         storage.copy_from(other.storage, count - 1)
      end

   is_equal(other: like Current): BOOLEAN is
      do
         if other = Current then
            Result := true
         elseif lower1 /= other.lower1 then
         elseif lower2 /= other.lower2 then
         elseif upper1 /= other.upper1 then
         elseif upper2 /= other.upper2 then
         else
            Result := storage.memcmp(other.storage,count)
         end
      end

feature -- Only for ARRAY2:

   transpose is
         -- Transpose the Current array
      local
         i,j : INTEGER
         oldu1,oldu2 : INTEGER
         oldl1,oldl2 : INTEGER
      do
         oldu1 := line_maximum
         oldu2 := column_maximum
         oldl1 := lower1
         oldl2 := lower2
         resize(lower1.min(lower2),
                line_maximum.max(column_maximum),
                lower1.min(lower2),
                line_maximum.max(column_maximum))
         from
            i := lower1
         until
            i > line_maximum
         loop
            from
               j := i + 1
            until
               j > column_maximum
            loop
               swap(i,j,j,i)
               j := j + 1
            end
            i := i + 1
         end
         resize(oldl2,oldu2,oldl1,oldu1)
      ensure
         line_minimum = old column_minimum
         column_minimum = old line_minimum
         line_maximum = old column_maximum
         column_maximum = old line_maximum
         count = old count
      end

   to_external: POINTER is
         -- Gives C access to the internal `storage' (may be dangerous).
      do
         Result := storage.to_external
      end

feature {COLLECTION2}

   same_as(other: COLLECTION2[E]): BOOLEAN is
      do
         Result := other.same_as_array2(Current)
      end

   same_as_array2(other: ARRAY2[E]): BOOLEAN is
      do
         Result := standard_same_as(other)
      end

   same_as_fixed_array2(other: FIXED_ARRAY2[E]): BOOLEAN is
      do
         Result := standard_same_as(other)
      end

invariant

   count2 = upper2 - lower2 + 1

   capacity >= count

end -- ARRAY2[E]