CODEWITHSUNDEEP
arraystypesada
Jonaswg
Jonaswg

Reputation: 404

Ada type conflict in array indices

This is the code and the algorithm works in Java but in Ada it still raises the CONSTRAINT_ERROR. In Ada we start indexing the array at 1 and not at 0 as in most other languages. For some reason I am still indexing out of array. 

 procedure spiral is

   M : Matrix := ((11,22,33,44,55),(1,8,3,8,9),(10,10,20,30,1));

   lastcol, firstcol, lastrow : Integer := 1;
   rowsize, colsize : Integer := 0;

   procedure Print ( M: in Matrix ) is
   begin

  rowsize := M'Length(1);
  colsize := M'Length(2);

  while lastrow<=rowsize loop

        for I in Index range Index(firstcol)..Index(colsize) loop
           Put( Elem'Image(M(Index(lastrow),Index(I))));
           Put( Ascii.HT );
        end loop;

        lastrow := lastrow + 1;

        if (lastrow>=rowsize) then 
           return;
        end if;

        for J in Index range Index(lastrow)..Index(rowsize) loop
           Put( Elem'Image(M(Index(J),Index(colsize))));
           Put( Ascii.HT );
        end loop;

        colsize := colsize - 1;


        for I in reverse Index range Index(colsize)..Index(lastcol) loop
           Put( Elem'Image(M(Index(rowsize), Index(I))));
           Put( Ascii.HT );
        end loop;

        rowsize := rowsize- 1;
        lastcol := lastcol+ 1;

        for I in reverse Index range Index(rowsize)..Index(lastrow) loop
           Put( Elem'Image(M(Index(I), Index(firstcol))));
           Put( Ascii.HT );
        end loop;

        firstcol := firstcol + 1;

     end loop;
   end Print;

begin
   --Put(rowDown);
   Print(M);
end spiral;

the Matrix package is defined as:

package Matrix_pack is

    type Index is new Integer;
    type Elem is new Integer;
    type Matrix is array (Index range <>, Index range <>) of Elem;

end Matrix_pack;

Upvotes: 0

Views: 377

Answers (1)

Jacob Sparre Andersen
Jacob Sparre Andersen

Reputation: 6601

The solution can be done in two steps:

  • First: Make the indexing type used in the loop explicit:
for I in Index range colLeft .. colRight loop
   Put (Elem'Image (M (rowUp, I)));
end loop;
  • Second: Fix the declarations of colLeft and colRight:
colLeft, colRight : Index;

Upvotes: 2

Related Questions