Re: Creating an empty file with Ada.Text_IO

["J-P. Rosen" <rosen@adalog.fr>]

Le 25/08/2015 17:26, Maciej Sobczak a écrit :
>> procedure Write_String_To_File (File_Name : in String; S : in String) is
>> >       A : Ada.Streams.Stream_Element_Array (1 .. S'Length);
>> >       F : Ada.Streams.Stream_IO.File_Type;
>> >    begin
>> >       -- convert S to stream elements
>> >       for I in S'Range loop
>> >          A (Ada.Streams.Stream_Element_Offset (I)) :=
>> >             Ada.Streams.Stream_Element (Character'Pos (S (I)));
>> >       end loop;
> Before anybody uses it in a rocket - there is no provision above that S'First will be 1 and the indices might not be compatible in the above assignment.
> 
> Correct version is:
> 
>       for I in S'Range loop
>          A (Ada.Streams.Stream_Element_Offset (I - S'First + 1)) :=
>             Ada.Streams.Stream_Element (Character'Pos (S (I)));
>       end loop;
Or simply:
      A : Ada.Streams.Stream_Element_Array
         (Stream_Element_Offset(S'First) ..
          Stream_Element_Offset(S'Last));

(saves some computation in the loop)
-- 
J-P. Rosen
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