Re: reading a text file into a string

[Dale Stanbrough <MrNoSpam@bigpoop.net.au>]

Robert I. Eachus wrote:


> 
> For this reason, I find myself contructing or using a Get_Line FUNCTION 
> inside a loop and a declare block:
> 
> while not End_of_Line(Somefile) loop
>    declare
>       Buffer: String := Get_Line(Somefile);
>    begin
>       -- process buffer
>    exception
>       ...
>    end;
> end loop;


I use a generic procedure that has a process procedure as a parameter.
It gets called with each line of the string...

--  Apply the procedure Process to each line of the file
--  This allows for very simple file processing, with all of the
--  control bits (not much really) hidden away.
--
--  Each line is read from the file, and then passed to the 
--  procedure
--  The maximum line size for the file is 1000 chars.
--
--  Typical use is
--
--    with Ada.Text_IO; use Ada.Text_IO;
--    with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
--
--    with Process_File;
--
--    procedure Count_Chars is
--
--       Count : Natural := 0;
--
--       procedure Count_Letters (Item : String) is
--       begin
--          Count := Count + Item'Length;
--       end;
--
--       procedure Count_Em is
--          new Process_File (Process => Count_Letters);
--   begin
--      Count_Em (<Somefilename>);
--      Put ("There are ..."); Put (Count); Put (" characters");
--   end;
--

generic
   with procedure Process (Line : String);
   Max_Line_Size : Positive := 1000;
   -- The maximum number of characters on any one line

procedure Process_File (Filename : String);


-----------------------------------------------------

it presumes a maximum line length, which is not so great, but
is otherwise a very convenient generic.

Dale

-- 
dstanbro@spam.o.matic.bigpond.net.au