Re: Random Input-Size and recognizing ENTER-press

[Jeffrey Carter <spam@spam.com>]

Pascal Obry wrote:

> That's not right. There is a buffer that is allocated when there is no more
> space into an Unbounded_String. So there is far less that N allocation when
> adding N characters into an Unbounded_String.

Here's what I have:

    Null_String : aliased String := "";

    function To_Unbounded (S : String) return Unbounded_String
      renames To_Unbounded_String;

    type Unbounded_String is new AF.Controlled with record
       Reference : String_Access := Null_String'Access;
    end record;

    procedure Append
      (Source   : in out Unbounded_String;
       New_Item : in Character)
    is
       S_Length : constant Integer := Source.Reference.all'Length;
       Length   : constant Integer := S_Length + 1;
       Tmp      : String_Access;

    begin
       Tmp := new String (1 .. Length);
       Tmp (1 .. S_Length) := Source.Reference.all;
       Tmp (S_Length + 1) := New_Item;
       Free (Source.Reference);
       Source.Reference := Tmp;
    end Append;

Starting with a null string, that certainly looks like N allocations.

-- 
Jeff Carter
"I was hobbling along, minding my own business, all of a
sudden, up he comes, cures me! One minute I'm a leper with
a trade, next minute my livelihood's gone! Not so much as a
'by your leave!' You're cured, mate. Bloody do-gooder!"
Monty Python's Life of Brian
76