Re: Pondering what rationale behind record type

[Martin <martin.dowie@btopenworld.com>]

On May 10, 1:50 pm, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
wrote:
> On Tue, 10 May 2011 14:18:28 +0200, Georg Bauhaus wrote:
> > On 10.05.11 14:08, Dmitry A. Kazakov wrote:
>
> >>> Anything wrong with (i.e. makes you shudder)
>
> >>>    Label_A: loop
> >>>      ...
> >>>    end loop Label_A;
>
> >>> ?
>
> >> loop A do
> >>    ...
> >> end A;
>
> > Consequently,
>
> > if ... then A do
> >    ...
> > else
> >    ...
> > end A;
>
> > I guess?
>
> What is the reason to name statements? But if you wanted to, it would be
>
> if A do <condition> then
>    ...
> else
>    ...
> end A;
>
>
>
>
>
>
>
>
>
> >>>    type Get_Token is function (File : File_Type) return
> >>>        ((Matched : Boolean; Length : Positive) record
> >>>            case Matched is
> >>>              when True => Token : String (1..Length);
> >>>              when False => null;
> >>>            end case;
> >>>         end record)
> >>>    end Get_Token;
>
> >> No, Get_Token would be a function-type.
>
> > Yes. It was suggested that the meat part of type declarations
> > should end in "end [X]", not "end keyword", so that
>
> >> E.g.
>
> >     type Func is
> >        function (X : Float) return Float;
> >     end Func;
>
> No, because here there is no left bracket that follows "is". Compare
>
>    type String is array (...) of ...;
>
> The type declaration syntax is:
>
>    type <name> is <definition>;
>
> <definition> can be:
>
> 1. plain, e.g. private; range ...; delta ...; array; access ...; mod ...
>
> 2. nested, like task, record, protected object. Their declarations are
> unfortunately irregular. They should have been
>
>    type Worker is task ... end Worker;
>    type Mutex is protected ... end Mutex;
>    type Data is record ... end Data;
>
> Of course one could deploy the alternative schema:
>
>    <class-name> type <name> is <definition>;
>
> E.g.
>
>    task type A is ... end A;
>    record type B is ... end B;
>    array type String is (Positive range <>) of Character;
>    range type Integer is -2**31-1..2**31-1;
>
> But mixing them was a bad idea.
>
> P.S. task and protected should have been record types with entries being
> primitive operations.
>
> --
> Regards,
> Dmitry A. Kazakovhttp://www.dmitry-kazakov.de

Doesn't 'type' become redundant at this point?...

-- Martin