Re: Constant record components

["ME" <abcdefg@nonodock.net>]

"Georg Bauhaus" <bauhaus@futureapps.de> wrote in message 
news:44afe7b2$0$29128$9b4e6d93@newsread4.arcor-online.net...
> ME wrote:
>> "Georg Bauhaus" <bauhaus@futureapps.de> wrote in message 
>> news:1152263715.5568.1.camel@localhost...
>>> On Thu, 2006-07-06 at 22:39 -0700, ME wrote:
>>>> What I am looking for is a way to read in a values from a file ,assign 
>>>> them
>>>> once to  records and disallow any future assignment i.e. these 
>>>> "constant
>>>> parts of the records represent a structure that I don't want to ever 
>>>> change
>>>> during the life of the program (write once and read only afterwards).
>>> Wouldn't it be an option to declare the public view
>>> of the to-be-constant record subtype limited?
>> The record has no discriminants
>
> Yes. What I meant has in fact little to do with discriminants.
> package P is
>
>   type C is limited private;
>     -- to be the constant part in R  -- C ops ...
>
>   type R is record  -- cannot be assigned because
but I need R to be assigned
anyway the unconstrained array of records R is private
>     immutable: C;  -- this cannot be assigned either (read only)
>     other_data: Integer;  -- (read/write)
>   end record;
>
>   type Grid is array(...) of R;
>
>   -- etc.
>
> private
>   type C is record
>      mutable: Integer;  -- can be assigned, e.g. during init
>   end record;
>
>   -- perform initialization in package body, maybe require
>   -- a suitable callback that reads initial values
>   -- ...
>
> end P;