Slicing & sliding

[matthewsj@saic.com (John B. Mattehws, M.D.)]

Given the following program

with Text_IO;

procedure Slice is

S : String (1 .. 64) := (others => '.');

    function F return String is
    begin
        return "result";
    end F;

begin

    Text_IO.Put_Line(S);
    S(S'Range) := F(S'Range);
    Text_IO.Put_Line(S);
    
end Slice;

The output is
................................................................
result

I was suprised to see that the indicated slice of F (F(S'Range)) is allowed
to be larger than the result returned by F, despite RM 4.1.2(7). For
smaller slices, the remainder of S seems to slide down, and the rest is
padded with nulls. Can someone help me understand this? Is this conformant
with the RM?

Thanks,

John
----
John B. Matthews, M.D.
matthewsj@saic.com; jmattthews@nova.wright.edu